#Astronomers may have found an Earth-like exoplanet orbiting a sun-like star

[mysticstronomy]

HOW DO ASTRONOMERS DETECT EXOPLANETS AND DETERMINE IF THEY COULD SUPPORT LIFE??

Blog#335

Wednesday, September 27th, 2023

Welcome back,

On March 21, NASA announced the confirmation of the 5,000th planet outside our Solar System. From scorching-hot gas giants nestled near their parent star to rocky worlds that may host water on their surface, there’s a variety for scientists to study.

But finding these strange new worlds is a science in itself.

We’ve only been able to definitively detect planets of any kind for a few decades, and even at that, there are challenges in detecting such a small object at that distance in even the most powerful telescopes.

Inverse spoke with Marie-Eve Naud, an exoplanet researcher and outreach coordinator for the University of Montreal’s Institute for Research on Exoplanets, to tell us more about how astronomers find these worlds and the considerations for each method.

While there are numerous methods, the ones cited below are the most common.

THE TRANSIT METHOD

Astronomers have discovered most exoplanets using the transit method, notably with NASA's Kepler telescope launched in 2009. This method observes planets as they pass in front of their stars, causing a slight dimming of starlight, which photometers can detect. This approach works best in space due to minimal atmospheric interference, favored by missions like ESA's Cheops and NASA's TESS.

To confirm exoplanets, multiple transits are necessary to rule out sunspots or dust as causes of light fluctuations. Typically, two or three transits are required to gather substantial data.

Once a planet is detected, astronomers can estimate its radius, while mass is often determined through the radial velocity method. The combination of mass and radius helps classify a planet as rocky or gaseous, impacting its potential habitability.

Factors like proximity to an active star and radiation levels also affect habitability assessments, as seen with TRAPPIST-1's uncertain habitability despite hosting seven Earth-sized planets in its habitable zone.

RADIAL-VELOCITY METHOD

The radial velocity method is commonly used to discover planets, particularly with instruments like HARPS at the European Southern Observatory’s La Silla 3.6m telescope in Chile.

Planets and stars both orbit around their center of mass. A star with a planet exhibits a slight motion. Multiple planets can lead to complex motions.

This method involves analyzing the star's spectrum. When the star approaches, its light shifts towards red due to compression. When it moves away, the light shifts towards blue.

The planet's motion slightly affects the star's spectrum, creating a "barcode" of the star.

The first detection of a planet around a Sun-like star using this method was in 1995 when Didier Queloz and Michel Mayor found 51 Pegasi b. Prior to that, in 1992, planets were detected around pulsar PSR B1257+12, using changes in the pulsar's radio signal. This showcases the diverse scientific approaches to discovering distant worlds.

Originally published on www.inverse.com

COMING UP!!

(Saturday, September 30th, 2023)

"WHAT IS THE BLOCK THEORY??"

#astronomy #outer space #alternate universe #astrophysics #universe #spacecraft #white universe #space #parallel universe #astrophotography #dwarf planet #planets #come to the dark side #dark energy #cosmology #cosmos #big bang comics

[mindblowingscience]

NASA's Kepler Space Telescope may have saved the best for last. Astronomers combing over data collected by the telescope before its retirement in 2018 have found a system of seven planets being blasted by radiation from their parent star. Each of the seven blisteringly hot extra-solar planets — or "exoplanets" — in the system Kepler-385 received more radiation from the sun-like star they orbit than any planet in the solar system receives from the sun. The planets all appear to be larger than Earth but smaller than the solar system ice-giant Neptune.  Excitingly, the Kepler-385 system is just one of the highlights in a new Kepler Space Telescope-created catalog of around 4,400 exoplanet candidates and 700 multi-planet systems that has astronomers thrilled about the information they might glean from it.

Continue Reading.

#Science #Kepler Space Telescope #Exoplanets #astronomy #space #stem

[kuramirocket]

Lead study Mexican author Luis Rodríguez, a professor emeritus at the Institute of Radio Astronomy and Astrophysics at the National Autonomous University of Mexico

In 2023, the James Webb Space Telescope (JWST) helped identify hundreds of free-floating "rogue" planets that don't orbit a parent star. Now, astronomers have found that a pair of these planets may be producing enigmatic, hard-to-interpret radio signals.

The rogue planets spotted by JWST lie in the Orion Nebula, a long-time observational hotspot for astronomers. In total, they number over 500. This discovery bonanza was possible thanks to JWST's ability to pick up infrared radiation emitted by these relatively young planets.

Bizarrely, though, about 80 of these planets exist as pairs. Similar in mass to Jupiter, the planets orbit each other at distances ranging from 25 to 400 times the distance between Earth and the sun. These tangoing duos, called Jupiter-mass binary objects (JuMBOs), pose a huge mystery for astronomers, because the existence of these worlds challenges current theories of planet formation. Some scientists think these objects may not even be planets but rather previously unknown entities that are larger than planets but smaller than brown dwarfs, which are sometimes called "failed stars" because they blur the line between planets and stars.

The JWST data showed that JuMBOs generated infrared radiation, but the new study's authors wanted to see if these dancing objects produced radio waves. That's because different classes of cosmic objects produce distinct patterns of radio emissions. For instance, planets like Jupiter spew several types of radio signals, including gigahertz-frequency emissions thousands of times higher-pitched than an FM signal, partly because of their magnetic fields.

Spotting such signatures from the JuMBOs could help resolve their identity. The observations could also explain "why some objects have detectable radio emission and others do not," lead study author Luis Rodríguez, a professor emeritus at the Institute of Radio Astronomy and Astrophysics at the National Autonomous University of Mexico, told Live Science in an email.

To find radio wave "snapshots" of the Orion Nebula where the JuMBOs reside, the scientists combed through archives of observations maintained by the U.S. National Radio Astronomy Observatory (NRAO). They found just one pair that apparently emits radio waves: JuMBO 24. Itself an oddity among the oddball objects, it's the heaviest of the JuMBOs, and also the one with the tightest space between its component planets.

A decade's worth of data the research team collated showed that the radio waves remained steady but strong, with a power of roughly a quarter of a ton of TNT and frequencies of 6 to 10 gigahertz. The radio waves also weren't circularly polarized, meaning they lacked spiral, twisting electric fields, the team reported in their study, published Jan. 8 in The Astrophysical Journal Letters.

But these features aren't what astronomers expect of signals created by planets." Circular polarization is an unambiguous indicator of the presence of magnetic fields," Rodríguez said. Without this, the team can't say definitively that the signals come from JuMBO 24 (assuming the planets have magnetic fields). Besides, radio emissions from other exoplanets are more variable and less intense.

Even if JuMBO 24 isn't a pair of planets but rather another type of cosmic duo, the signals are unusual. Signals from brown dwarfs are very different from the newly identified radio beams. The beams' brightness and frequency even ruled out the possibility of pulsars, the rapidly spinning cores of dead stars that produce pulses of radio waves at regular intervals.

The researchers also estimated the likelihood that the signals originate from an object behind JuMBO 24 and found it to be exceedingly slim, at just 1 in 10,000. And, in case you were wondering, the signals probably don't originate from aliens.  "The fact that both components emit at similar levels favors a natural mechanism," Rodríguez said.

With the research at an impasse, the team is applying to the NRAO's Very Large Array in New Mexico to collect data from free-floating planets. Until then, the radio signals will remain a mystery.

#🇲🇽 #STEM #Luis Rodríguez #mexican scientists #astronomy #science #Institute of Radio Astronomy and Astrophysics #National Autonomous University of Mexico #James Webb Space Telescope #JWST #radio signals #planets #orion nebula #Jupiter-mass binary objects #JuMBOs #brown dwarfs #jupiter #JuMBO 24 #The Astrophysical Journal Letters #pulsars #mexican #latino #hispanic

[spacetimewithstuartgary]

In search for alien life, purple may be the new green

From house plants and gardens to fields and forests, green is the color we most associate with surface life on Earth, where conditions favored the evolution of organisms that perform oxygen-producing photosynthesis using the green pigment chlorophyll a.

But an Earth-like planet orbiting another star might look very different, potentially covered by bacteria that receive little or no visible light or oxygen, as in some environments on Earth, and instead use invisible infrared radiation to power photosynthesis.

Instead of green, many such bacteria on Earth contain purple pigments, and purple worlds on which they are dominant would produce a distinctive "light fingerprint" detectable by next-generation ground- and space-based telescopes, Cornell scientists report in new research.

"Purple bacteria can thrive under a wide range of conditions, making it one of the primary contenders for life that could dominate a variety of worlds," said Lígia Fonseca Coelho, a postdoctoral associate at the Carl Sagan Institute (CSI) and first author of "Purple is the New Green: Biopigments and Spectra of Earth-like Purple Worlds," published in Monthly Notices of the Royal Astronomical Society.

"We need to create a database for signs of life to make sure our telescopes don't miss life if it happens not to look exactly like what we encounter around us every day," added co-author Lisa Kaltenegger, CSI director and associate professor of astronomy in the College of Arts and Sciences.

Astronomers have confirmed more than 5,500 exoplanets to date, including more than 30 potentially Earth-like planets. Planned observatories such as the Extremely Large Telescope and Habitable Worlds Observatory will explore the chemical makeup of these worlds in their stars' habitable zones—where conditions are conducive to the existence of liquid water on surface—and analyses of their composition.

Using life on Earth as a guide, CSI's multidisciplinary team of scientists—also including William Philpot, professor emeritus in the School of Civil and Environmental Engineering in Cornell Engineering, and Stephen Zinder, professor emeritus of microbiology in the College of Agriculture and Life Sciences—are cataloging the colors and chemical signatures that a diverse range of organisms and minerals would present in an exoplanet's reflected light.

Coelho collected and grew samples of more than 20 purple sulfur and purple non-sulfur bacteria that may be found in a variety of environments, from shallow waters, coasts, and marshes to deep-sea hydrothermal vents.

Zinder and Coelho scooped some samples from a pond on Cornell's campus, while others were retrieved from waters off Cape Cod by Coelho during the 2023 Microbial Diversity summer course at the Marine Biological Laboratory at Woods Hole and from lab cultures maintained by collaborators from the University of Minnesota's Department of Plant and Microbial Biology, Associate Professor Trinity Hamilton and doctoral student Taylor Price.

What is collectively referred to as purple bacteria actually have a range of colors, including yellow, orange, brown, and red, due to pigments related to those that make tomatoes red and carrots orange. They thrive on low-energy red or infrared light using simpler photosynthesis systems utilizing forms of chlorophyll that absorb infrared and don't make oxygen.

They are likely to have been prevalent on early Earth before the advent of plant-type photosynthesis, the researchers said and could be particularly well-suited to planets that circle cooler red dwarf stars—the most common type in our galaxy.

"They already thrive here in certain niches," Coelho said. "Just imagine if they were not competing with green plants, algae, and bacteria: A red sun could give them the most favorable conditions for photosynthesis."

After measuring the purple bacteria's biopigments and light fingerprints, the researchers created models of Earth-like planets with varying conditions and cloud cover. Across a range of simulated environments, Coelho said, both wet and dry purple bacteria produced intensely colored biosignatures.

"If purple bacteria are thriving on the surface of a frozen Earth, an ocean world, a snowball Earth, or a modern Earth orbiting a cooler star," Coelho said, "we now have the tools to search for them."

Detecting a "pale purple dot" in another solar system would trigger intensive observations of the planet to try to rule out other color sources, such as colorful minerals, which CSI is also cataloging.

Kaltenegger, author of the forthcoming book, "Alien Earths: The New Science of Planet Hunting in the Cosmos," said detecting life is so difficult with current technology that if even single-celled organisms are found in one place, it would suggest that life must be widespread in the cosmos. That would revolutionize our thinking about the age-old question: Are we alone in the universe?

"We are just opening our eyes to these fascinating worlds around us," Kaltenegger said. "Purple bacteria can survive and thrive under such a variety of conditions that it is easy to imagine that on many different worlds, purple may just be the new green."

#science #space #astronomy #physics #news #astrophysics

[mit]

Newly discovered planet has longest orbit yet detected by the TESS mission

The frosty gas giant was discovered in a system that also hosts a warm Jupiter.

Jennifer Chu | MIT News

Of the more than 5,000 planets known to exist beyond our solar system, most orbit their stars at surprisingly close range. More than 80 percent of confirmed exoplanets have orbits shorter than 50 days, placing these toasty worlds at least twice as close to their star as Mercury is to our sun — and some, even closer than that.

Astronomers are starting to get a general picture of these planets’ formation, evolution, and composition. But the picture is much fuzzier for planets with longer orbital periods. Far-out worlds, with months- to years-long orbits, are more difficult to detect, and their properties have therefore been trickier to discern.

Now, the list of long-period planets has gained two entries. Astronomers at MIT, the University of New Mexico, and elsewhere have discovered a rare system containing two long-period planets orbiting TOI-4600, a nearby star that is 815 light years from Earth.

The team discovered that the star hosts an inner planet with an orbit of 82 days, similar to that of Mercury, while a second outer planet circles every 482 days, placing it somewhere between the orbits of Earth and Mars.

The discovery was made using data from NASA’s Transiting Exoplanet Survey Satellite, or TESS — an MIT-led mission that monitors the nearest stars for signs of exoplanets. The new, farther planet has the longest period that TESS has detected to date. It is also one of the coldest, at about -117 degrees Fahrenheit, while the inner planet is a more temperate 170 degrees Fahrenheit.

Both planets are likely gas giants, similar to Jupiter and Saturn, though the composition of the inner planet may be more of a mix of gas and ice. The two planets bridge the gap between “hot Jupiters” — the toasty, short-orbit planets that make up the majority of exoplanet discoveries — and the much colder, longer-period gas giants in our solar system.

“These longer-period systems are a comparatively unexplored range,” says team member Katharine Hesse, a technical staff member at MIT’s Kavli Institute for Astrophysics and Space Research. “As we’re trying to see where our solar system falls in comparison to the other systems we’ve found out there, we really need these more edge-case examples to better understand that comparison. Because a lot of systems we have found don’t look anything like our solar system.”

Hesse and her colleagues, including lead author Ismael Mireles, a graduate student at the University of New Mexico (UNM), have published their results today in Astrophysical Journal Letters.

Patch work

TESS monitors the nearest stars for signs of exoplanets by pointing at a patch of the sky and continuously measuring the brightness of stars in that sector for 30 days, before swiveling to the next patch. Scientists use “pipelines,” or algorithmic searches, to comb through the measurements for dips in brightness that could have been caused by a planet passing in front of its star.

In 2020, one pipeline picked up a possible transit from a star in the northern sky, close to the constellation Draco. The star was categorized as TOI-4600 (a TESS Object of Interest). The initial transit was studied in detail by the TESS Single Transit Planet Candidate Working Group, a team of scientists at MIT, UNM, and elsewhere who look for signs of longer-period planets in single-transit events.

“For missions like TESS, where it only looks at each region of the sky for 30 days, you really need to stack up the number of observations to be able to get enough data to find planets with orbits longer than a month,” Hesse notes.

The group looked for the star in other sectors of TESS data and eventually identified three more transits, similar to the first. From these four events, the scientists were able to determine that the source was a planet — TOI-4600b — with a relatively long 82-day orbit. The team also picked up a fifth transit, though it was out of sync with the other signals. They wondered: Could the transit be from another star temporarily eclipsing the first? Or could it be a second orbiting planet?

Giants in the sky

In 2021, when Mireles joined the group, he took up where the team left off, looking for more observations from TESS that would explain the last, puzzling transit.

“With each sector of data that came down, I would look to see if there was a second transit, and in the first five sectors, there wasn’t,” Mireles recalls. “Then, in July of last year, we saw something.”

Actually, they saw two things: one transit that appeared in the same 82-day cycle, which further confirmed the existence of a long-orbiting planet; and a second transit, which was detected 964 days after the previous, out-of-sync transit. These last two transits were similar in depth, or the amount of light that was dimmed, suggesting that both were produced by a single object that was orbiting the star, either every 964 days, or every 482 days. After all, the team reasoned, TESS simply could have not been looking in the star’s direction to catch the planet crossing at the 482-day mark. The team used a model to simulate what a planet would look like with both orbital periods, and concluded that the 482-day orbit was more likely.

To further confirm they had identified two long-period planets, the researchers focused in on the star using multiple ground-based telescopes. These observations helped the team rule out false-positive scenarios, such as a second star eclipsing the main star. In the end, they concluded that the star indeed hosts two long-period planets: TOI-4600b, a warm, Jupiter-like giant; and TOI-4600c, a frosty, icier giant, and the longest-period planet detected by TESS to date.

“It’s relatively rare that we see two giant planets in a system,” Hesse offers. “We’re used to seeing hot Jupiters that are close in to their stars, and we usually don’t find companions to them, let alone giant companions. This system is a more unique configuration.”

The distance between the two planets, which is about the same as the space between Mercury and Mars, implies there could be other planets in the system.

“We want to see if there’s evidence for more planets,” Mireles says. “There’s definitely a lot of room for potential planets, either closer in, or further out. And we show that TESS is capable of finding both warm and cold Jupiters.”

 This research was supported, in part, by NASA.

Make sure to follow us on Tumblr!

#planet #exoplanets #astronomy #nasa #planetary science #space exploration

[sciencespies]

Astronomers May Have Found the Galaxy’s Youngest Planet

https://sciencespies.com/space/astronomers-may-have-found-the-galaxys-youngest-planet/

Astronomers May Have Found the Galaxy’s Youngest Planet

The Webb telescope soon will help measure the world, which may offer insights into how our own formed.

Over the last 30 years, astronomers have found more than 5,000 exoplanets, an eclectic menagerie of worlds far from our stellar neighborhood. The latest may be a mere infant.

In the journal The Astrophysical Journal Letters, scientists on Tuesday announced compelling evidence for a world just 1.5 million years old, making it one of the youngest planets ever found, perhaps the youngest.

This world — 395 light-years from Earth in the constellation Ophiuchus — is so young that its building blocks of gas and dust are still coming together. This planet is a newborn being cradled in the arms of its parent star.

“It is like looking at our own past,” said Myriam Benisty, an astronomer at the Institute of Planetology and Astrophysics of Grenoble in France and a co-author of the study.

As the suspected planet is shrouded by the matter that is making it, further telescopic observations will be required to confirm its existence. Presuming it isn’t rocky detritus masquerading as a planet, scientists can use it to better understand how worlds are made.

The torrent of newly discovered exoplanets has complicated or disproved longstanding theories of planet formation. But the location of this baby planet — firmly within the disk of primordial matter around its star — supports the idea that most planets spend much of their time growing up in a similar sort of nursery.

The discovery of the celestial pip suggests “all planetary systems have a common formation process,” said Anders Johansen, an astronomer at Lund University in Sweden who was not involved with the study. Despite the chaos of the cosmos, he said, “there is actually a lot of order” when it comes to crafting planets.

The team of scientists used the Atacama Large Millimeter/submillimeter Array (ALMA), a collection of 66 antennas acting in unison in Chile, to gather evidence of this exceedingly young world. Gas and dust orbits certain stars in so-called circumstellar disks. This material, which clumps together to form planets within these disks, emits radio waves that ALMA can detect.

Last year, Dr. Benisty and her colleagues used ALMA to make the first unambiguous detection of a halo of gas and dust orbiting an exoplanet: a circumplanetary foundry still making the world it shrouded, and perhaps a few moons too.

For the latest study, they pointed ALMA at AS 209, a star just a tad heavier than the sun. Just 1.5 million years of age, it has only recently started to burn hydrogen — the stellar equivalent of a toddler uttering its first words.

AS 209’s circumstellar disk was found to have several gaps. And in one such gap, ALMA detected the radio-wave signature of a planet-making tempest, gas that was presumably enveloping a Jupiter-like world still under construction.

The planet’s precise age won’t be resolved soon, but it’s likely to be very similar to its nascent star. But its youth is not the only thing piquing astronomers’ interests. It is also bafflingly far from its star. Neptune, the outermost planet in our solar system, is roughly 2.8 billion miles from the sun. This exoplanet is almost 19 billion miles away from its own star.

That raises questions about our own neck of the woods.

The size of the debris disk that forged Earth and the other planets is uncertain. “Maybe the disc was only slightly larger than Neptune’s orbit, and that is why Neptune is the outermost planet,” Dr. Johansen said. But perhaps our hub of planet-making matter was more like AS 209’s. If so, “we also cannot rule out that our own solar system has a planet beyond Neptune,” he said — perhaps the hypothesized Planet 9 that some astronomers suspect is lingering in distant darkness.

In the coming days, the James Webb Space Telescope will determine the mass of the planetary newborn and study its atmospheric chemistry. And by painting a detailed portrait of one of the youngest worlds known to science, these observations will inch us all closer to answering the ultimate question, said Jaehan Bae, an astronomer at the University of Florida and an author of the study: “Where did we come from?”

#Space

#Space

[spacenutspod]

The search for extrasolar planets is currently undergoing a seismic shift. With the deployment of the Kepler Space Telescope and the Transiting Exoplanet Survey Satellite (TESS), scientists discovered thousands of exoplanets, most of which were detected and confirmed using indirect methods. But in more recent years, and with the launch of the James Webb Space Telescope (JWST), the field has been transitioning toward one of characterization. In this process, scientists rely on emission spectra from exoplanet atmospheres to search for the chemical signatures we associate with life (biosignatures). However, there’s some controversy regarding the kinds of signatures scientists should look for. Essentially, astrobiology uses life on Earth as a template when searching for indications of extraterrestrial life, much like how exoplanet hunters use Earth as a standard for measuring “habitability.” But as many scientists have pointed out, life on Earth and its natural environment have evolved considerably over time. In a recent paper, an international team demonstrated how astrobiologists could look for life on TRAPPIST-1e based on what existed on Earth billions of years ago. The team consisted of astronomers and astrobiologists from the Global Systems Institute, and the Departments of Physics and Astronomy, Mathematics and Statistics, and Natural Sciences at the University of Exeter. They were joined by researchers from the School of Earth and Ocean Sciences at the University of Victoria and the Natural History Museum in London. The paper that describes their findings, “Biosignatures from pre-oxygen photosynthesizing life on TRAPPIST-1e,” will be published in the Monthly Notices of the Royal Astronomical Society (MNRAS). The TRAPPIST-1 system has been the focal point of attention ever since astronomers confirmed the presence of three exoplanets in 2016, which grew to seven by the following year. As one of many systems with a low-mass, cooler M-type (red dwarf) parent star, there are unresolved questions about whether any of its planets could be habitable. Much of this concerns the variable and unstable nature of red dwarfs, which are prone to flare activity and may not produce enough of the necessary photons to power photosynthesis. With so many rocky planets found orbiting red dwarf suns, including the nearest exoplanet to our Solar System (Proxima b), many astronomers feel these systems would be the ideal place to look for extraterrestrial life. At the same time, they’ve also emphasized that these planets would need to have thick atmospheres, intrinsic magnetic fields, sufficient heat transfer mechanisms, or all of the above. Determining if exoplanets have these prerequisites for life is something that the JWST and other next-generation telescopes – like the ESO’s proposed Extremely Large Telescope (ELT) – are expected to enable. But even with these and other next-generation instruments, there is still the question of what biosignatures we should look for. As noted, our planet, its atmosphere, and all life as we know it have evolved considerably over the past four billion years. During the Archean Eon (ca. 4 to 2.5 billion years ago), Earth’s atmosphere was predominantly composed of carbon dioxide, methane, and volcanic gases, and little more than anaerobic microorganisms existed. Only within the last 1.62 billion years did the first multi-celled life appear and evolve to its present complexity. Moreover, the number of evolutionary steps (and their potential difficulty) required to get to higher levels of complexity means that many planets may never develop complex life. This is consistent with the Great Filter Hypothesis, which states that while life may be common in the Universe, advanced life may not. As a result, simple microbial biospheres similar to those that existed during the Archean could be the most common. The key, then, is to conduct searches that would isolate biosignatures consistent with primitive life and the conditions that were common to Earth billions of years ago. This artistic conception illustrates large asteroids penetrating Earth’s oxygen-poor atmosphere. Credit: SwRI/Dan Durda/Simone Marchi As Dr. Jake Eager-Nash, a postdoctoral research fellow at the University of Victoria and the lead author of the study, explained to Universe Today via email: “I think the Earth’s history provides many examples of what inhabited exoplanets may look like, and it’s important to understand biosignatures in the context of Earth’s history as we have no other examples of what life on other planets would look like. During the Archean, when life is believed to have first emerged, there was a period of up to around a billion years before oxygen-producing photosynthesis evolved and became the dominant primary producer, oxygen concentrations were really low. So if inhabited planets follow a similar trajectory to Earth, they could spend a long time in a period like this without biosignatures of oxygen and ozone, so it’s important to understand what Archean-like biosignatures look like.” For their study, the team crafted a model that considered Archean-like conditions and how the presence of early life forms would consume some elements while adding others. This yielded a model in which simple bacteria living in oceans consume molecules like hydrogen (H) or carbon monoxide (CO), creating carbohydrates as an energy source and methane (CH4) as waste. They then considered how gases would be exchanged between the ocean and atmosphere, leading to lower concentrations of H and CO and greater concentrations of CH4. Said Eager-Nash: “Archean-like biosignatures are thought to require the presence of methane, carbon dioxide, and water vapor would be required as well as the absence of carbon monoxide. This is because water vapor gives you an indication there is water, while an atmosphere with both methane and carbon monoxide indicates the atmosphere is in disequilibrium, which means that both of these species shouldn’t exist together in the atmosphere as atmospheric chemistry would convert all of the one into the other, unless there is something, like life that maintains this disequilibrium. The absence of carbon monoxide is important as it is thought that life would quickly evolve a way to consume this energy source.” Artist’s impression of Earth in the early Archean with a purplish hydrosphere and coastal regions. Even in this early period, life flourished and was gaining complexity. Credit: Oleg Kuznetsov When the concentration of gases is higher in the atmosphere, the gas will dissolve into the ocean, replenishing the hydrogen and carbon monoxide consumed by the simple life forms. As biologically produced methane levels increase in the ocean, it will be released into the atmosphere, where additional chemistry occurs, and different gases are transported around the planet. From this, the team obtained an overall composition of the atmosphere to predict which biosignatures could be detected. “What we find is that carbon monoxide is likely to be present in the atmosphere of an Archean-like planet orbiting an M-Dwarf,” said Eager-Nash. “This is because the host star drives chemistry that leads to higher concentrations of carbon monoxide compared to a planet orbiting the Sun, even when you have life-consuming this [compound].” For years, scientists have considered how a circumsolar habitable zone (CHZ) could be extended to include Earth-like conditions from previous geological periods. Similarly, astrobiologists have been working to cast a wider net on the types of biosignatures associated with more ancient life forms (such as retinal-photosynthetic organisms). In this latest study, Eager-Nash and his colleagues have established a series of biosignatures (water, carbon monoxide, and methane) that could lead to the discovery of life on Archean-era rocky planets orbiting Sun-like and red dwarf suns. Further Reading: arXiv The post Will We Know if TRAPPIST-1e has Life? appeared first on Universe Today.

#space #astronomy #news #science

[jcmarchi]

Earth-Sized Planet Discovered in ‘Our Solar Backyard’ - Technology Org

New Post has been published on https://thedigitalinsider.com/earth-sized-planet-discovered-in-our-solar-backyard-technology-org/

Earth-Sized Planet Discovered in ‘Our Solar Backyard’ - Technology Org

A team of astronomers have discovered a planet closer and younger than any other Earth-sized world yet identified. It’s a remarkably hot world whose proximity to our own planet and to a star like our sun mark it as a unique opportunity to study how planets evolve.

Young, hot, Earth-sized planet HD 63433d sits close to its star in the constellation Ursa Major, while two neighboring, mini-Neptune-sized planets — identified in 2020 — orbit farther out. Illustration by Alyssa Jankowski, UW–Madison

The new planet was described in a new study published by The Astronomical Journal. Melinda Soares-Furtado, a NASA Hubble Fellow at the University of Wisconsin–Madison who will begin work as an astronomy professor at the university in the fall, and recent UW–Madison graduate Benjamin Capistrant, now a graduate student at the University of Florida, co-led the study with co-authors from around the world.

“It’s a useful planet because it may be like an early Earth,” says Soares-Furtado.

Here is what scientists know about the planet:

The planet is known as HD 63433d and it’s the third planet found in orbit around a star called HD 63433.

HD 63433d is so close to its star, it completes a trip all the way around every 4.2 days.

“Even though it’s really close-orbiting, we can use follow-up data to search for evidence of outgassing and atmospheric loss that could be important constraints on how terrestrial worlds evolve,” Soares-Furtado says. “But that’s where the similarities end — and end dramatically.”

Based on its orbit, the astronomers are relatively certain HD 63433d is tidally locked, which means one side is perpetually facing its star.

That side can reach a brutal 2,300 degrees Fahrenheit and may flow with lava, while the opposite side is forever dark.

What you should know about the planet’s star:

HD 63433 is roughly the same size and star type as our sun, but (at about 400 million years old) it’s not even one-tenth our sun’s age.

The star is about 73 light years away from our own sun and part of the group of stars moving together that make up the constellation Ursa Major, which includes the Big Dipper.

“On a dark night in Madison,” Soares-Furtado says, “you could see [HD 63433] through a good pair of binoculars.”

How the scientists found the planet:

The study’s authors are collaborating on a planet-hunting project called THYME. In 2020, they used data from NASA’s Transiting Exoplanet Survey Satellite to identify two mini-Neptune-sized planets orbiting HD 63433.

Since then, TESS took four more looks at the star, compiling enough data for the researchers to detect HD 63433d crossing between the star and the satellite.

What comes next:

The researchers, including UW–Madison study co-authors graduate student Andrew C. Nine, undergraduate Alyssa Jankowski and Juliette Becker, a UW–Madison astronomy professor, think there is plenty to learn from HD 63433d.

The planet is uniquely situated for further study. Its peppy young star is visible from both the Northern and Southern hemispheres, increasing the number of instruments, like the South African Large Telescope or WIYN Observatory in Arizona (both of which UW–Madison helped design and build) that can be trained on the system.

And the star is orders of magnitude closer than many Soares-Furtado has studied, possibly affording opportunities to develop new methods to study gasses escaping from the planet’s interior or measure its magnetic field.

“This is our solar backyard, and that’s kind of exciting,” Soares-Furtado says. “What sort of information can a star this close, with such a crowded system around it, give away? How will it help us as we move on to look for planets among the maybe 100 other, similar stars in this young group it’s part of?”

Source: University of Wisconsin-Madison

You can offer your link to a page which is relevant to the topic of this post.

#Astronomy #Astronomy news #Dark #data #Design #earth #exoplanet #Exoplanets #Featured Space news #how #Hubble #illustration #it #lava #Learn #LED #Light #Link #magnetic field #measure #NASA #Neptune #One #opposite #orbit #Other #Planetary exploration #planets #project #satellite

[hobbyspacer]

ESO: Two exoplanets may share same orbit

A new report from the European Southern Observatory (ESO): Does this exoplanet have a sibling sharing the same orbit?

This image, taken with the Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner, shows the young planetary system PDS 70, located nearly 400 light-years away from Earth. The system features a star at its centre, around which the planet PDS 70 b (highlighted with a solid yellow circle) is orbiting. On the same orbit as PDS 70b, indicated by a solid yellow ellipse, astronomers have detected a cloud of debris (circled by a yellow dotted line) that could be the building blocks of a new planet or the remnants of one already formed. The ring-like structure that dominates the image is a circumstellar disc of material, out of which planets are forming. There is in fact another planet in this system: PDS 70c, seen at 3 o’clock right next to the inner rim of the disc. Using the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers have found the possible ‘sibling’ of a planet orbiting a distant star. The team has detected a cloud of debris that might be sharing this planet’s orbit and which, they believe, could be the building blocks of a new planet or the remnants of one already formed. If confirmed, this discovery would be the strongest evidence yet that two exoplanets can share one orbit. “Two decades ago it was predicted in theory that pairs of planets of similar mass may share the same orbit around their star, the so-called Trojan or co-orbital planets. For the first time, we have found evidence in favour of that idea,” says Olga Balsalobre-Ruza, a student at the Centre for Astrobiology in Madrid, Spain who led the paper published today in Astronomy & Astrophysics. https://youtu.be/T7-cp8Om_qU Trojans, rocky bodies in the same orbit as a planet, are common in our own Solar System , the most famous example being the Trojan asteroids of Jupiter — more than 12 000 rocky bodies that are in the same orbit around the Sun as the gas giant. Astronomers have predicted that Trojans, in particular Trojan planets, could also exist around a star other than our Sun, but evidence for them is scant. “Exotrojans have so far been like unicorns: they are allowed to exist by theory but no one has ever detected them,” says co-author Jorge Lillo-Box, a senior researcher at the Centre for Astrobiology. Now, an international team of scientists have used ALMA, in which ESO is a partner, to find the strongest observational evidence yet that Trojan planets could exist — in the PDS 70 system. This young star is known to host two giant, Jupiter-like planets, PDS 70b and PDS 70c. By analysing archival ALMA observations of this system, the team spotted a cloud of debris at the location in PDS 70b’s orbit where Trojans are expected to exist. https://youtu.be/0HWvXmfO5PU Trojans occupy the so-called Lagrangian zones, two extended regions in a planet's orbit where the combined gravitational pull of the star and the planet can trap material. Studying these two regions of PDS 70b’s orbit, astronomers detected a faint signal from one of them, indicating that a cloud of debris with a mass up to roughly two times that of our Moon might reside there. The team believes this cloud of debris could point to an existing Trojan world in this system, or a planet in the process of forming. “Who could imagine two worlds that share the duration of the year and the habitability conditions? Our work is the first evidence that this kind of world could exist,” “We can imagine that a planet can share its orbit with thousands of asteroids as in the case of Jupiter, but it is mind blowing to me that planets could share the same orbit.” “Our research is a first step to look for co-orbital planets very early in their formation,” says co-author Nuria Huélamo, a senior researcher at the Centre for Astrobiology. "It opens up new questions on the formation of Trojans, how they evolve and how frequent they are in different planetary systems,” adds Itziar De Gregorio-Monsalvo, ESO Head of the Office for Science in Chile, who also contributed to this research. To fully confirm their detection, the team will need to wait until after 2026, when they will aim to use ALMA to see if both PDS 70b and its sibling cloud of debris move significantly along their orbit together around the star. “This would be a breakthrough in the exoplanetary field,” says Balsalobre-Ruza. "The future of this topic is very exciting and we look forward to the extended ALMA capabilities, planned for 2030, which will dramatically improve the array’s ability to characterise Trojans in many other stars," concludes De Gregorio-Monsalvo. Notes When asteroids in Jupiter’s orbit were first discovered, they were named after heroes of the Trojan war, giving rise to the name Trojans to refer to these objects. === Amazon Ad === Celestron - NexStar 130SLT Computerized Telescope - Compact and Portable - Newtonian Reflector Optical Design - SkyAlign Technology - Computerized Hand Control - 130mm Aperture Read the full article

[myfeeds]

Exoplanet may reveal secrets about the edge of habitability

“Super-Earth” LP 890-9c (also named SPECULOOS-2c) is providing important insights about conditions at the inner edge of a star’s habitable zone and why Earth and Venus developed so differently, according to new research led by Lisa Kaltenegger, associate professor of astronomy at Cornell University. Her team found LP 890-9c, which orbits close to the inner edge of its solar system’s habitable zone, would look vastly different depending on whether it still had warm oceans, a steam atmosphere, or if it had lost its water — assuming it once had oceans like Earth’s. “Looking at this planet will tell us what’s happening on this inner edge of the habitable zone — how long a rocky planet can maintain habitability when it starts to get hot,” Kaltenegger said. “It will teach us something fundamental about how rocky planets evolve with increasing starlight, and about what will one day happen to us and Earth.” Kaltenegger is the lead author of “Hot Earth or Young Venus? A Nearby Transiting Rocky Planet Mystery,” published in Monthly Notices of the Royal Astronomical Society: Letters. LP 890-9c is one of two super-Earths orbiting a red dwarf star located 100 light years from Earth, researchers announced last year. They said liquid water or an atmosphere rich in water vapor was possible on LP 890-9c, which is about 40% larger than Earth and circles the small, cool star in 8.5 days. Those criteria suggested it to be one of the best targets for JWST to study among the known, potentially habitable terrestrial planets, in addition to the TRAPPIST-1 system. The team’s models are the first to detail differences in the chemical signatures generated by rocky planets near the habitable zone’s interior boundary, based on variables including the planet’s size, mass, chemical makeup, surface temperature and pressure, atmospheric height and cloud cover. The calculations were key to estimating how much time JWST would need to confirm the basic composition of an atmosphere — if there is one. The models span several scenarios thought to reflect stages of rocky planets’ evolution, ranging from a “hot Earth” where life might still be possible, to a desolate Venus featuring a carbon dioxide atmosphere. In between are phases Earth is expected to experience as the sun grows brighter and hotter with age, causing the oceans to gradually evaporate and fill the atmosphere with steam before boiling off entirely. How long those processes might take is unknown, and the astronomers say LP 890-9c provides a rare opportunity to explore that evolution. “This planet is the first target where we can test these different scenarios,” Kaltenegger said. “If it’s still a hotter Earth — hot, but with liquid water and conditions for life — then the timeline is slower than we thought. If we see that it’s already a full-blown Venus, then the water gets lost fast.” It’s possible that LP 890-9c has no atmosphere and hosts no life, or that it resembles a Venus with thick clouds that would block light from reflecting and thus yield little information. Deeper investigation promises to provide valuable clues, Kaltenegger said. “We don’t know what this planet on the edge of habitability could be like, so we have to look,” she said. “This is what real exploration is about.”

[twinhood-2dot0]

Awesome Science Finds

What. An. Awesome. Post, Alia.

Inspired, I wanted to do a sciencey one as well, although I'd planned a, uhm, somwhat mushy (and handwritten) one, but I'm a teensy tinsy bit short on time and sanity so here we are.

Monkeys Choke When Stressed?

We all know what we feel like when we’re in a super stressful situation, whether someone or you is in danger, or you’re in an exam hall, or you’re in the locker room, with the weight of expectations and the desire to win making you wanna freak out, or whether you’re up on the stage, with several eyes on you.

There has, however, been little research regarding animals in high-pressure situations, but a study on monkeys had found some fascinating similarities.

These results from psychologists at Georgia State University in Atlanta are the first evidence that other animals are also affected by stress from pressure to perform.

Basically, monkeys too “choke under pressure”.

Science Daily had also written a great article explaining how the researchers got these results.

Here's a quote from their abstract about their fascinating methodology

"...we trained capuchin monkeys on a computer game that had clearly denoted high- and low-pressure trials, then tested them on trials with the same signals of high pressure, but no difference in task difficulty. Monkeys significantly varied in whether they performed worse or better on high-pressure testing trials and performance improved as monkeys gained experience with performing under pressure. Baseline levels of cortisol were significantly negatively related to performance on high-pressure trials as compared to low-pressure trials. Taken together, this indicates that less experience with pressure may interact with long-term stress to produce choking behavior in early sessions of a task. Our results suggest that performance deficits (or improvements) under pressure are not solely due to human specific factors but are rooted in evolutionarily conserved biological factors."

Espresso isn't just the name of a way of consuming coffee, and you can use it to find new planets

ESPRESSO is also Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations. You know how space research centers love their acronyms.

Using ESPRESSO, we have even discovered a new planet, almost for sure!

Last year, scientists found evidence suggesting that there’s a planet we didn’t know of till now, orbiting Proxima Centauri, the closest star to us apart from our ­Sun. Proxima D.

So far, we had only found two other planets around Proxima Centauri and the coolest thing about this new one is that it’s super lightweight; in fact, one of the lighest planets we’ve found outside our solar system.

It’s like, a quarter of the mass of earth.

A team of astronomers had found this evidence using the, and I’m not making this up, the European Southern Observatory's Very Large Telescope or ESO's VLT, located in Chile and using our old friend ESPRESSO, with one of its really precise instruments for confirmation of the observations.

This discovery could give us key insight on finding other places that might host life, because it showed that the method they used for finding Proxima D, known as radial velocity technique, can recognize light planets, like the Earth, that our galaxy might very likely be teeming with.

The radial velocity technique basically picks up minute wobbles of stars caused by gravitation pull of planets orbiting it. And since F=ma and our Proxima D is super lightweight, the wobbles were particularly teeny.

Bravo, astronomers! Good job detecting those signals and interpreting them!

https://www.aanda.org/articles/aa/full_html/2022/02/aa42337-21/aa42337-21.html

I'll have more next week!

#science #nerdy #proxima centauri #proxima d #dftba #espresso

[nafiz4368dm]

What is the Universe?

What is the Universe?

The universe is everything. It includes all of space, and all the matter and energy that space contains. It even includes time itself and, of course, it includes you.

Earth and the Moon are part of the universe, as are the other planets and their many dozens of moons. Along with asteroids and comets, the planets orbit the Sun. The Sun is one among hundreds of billions of stars in the Milky Way galaxy, and most of those stars have their own planets, known as exoplanets.

The Milky Way is but one of billions of galaxies in the observable universe — all of them, including our own, are thought to have supermassive black holes at their centers. All the stars in all the galaxies and all the other stuff that astronomers can’t even observe are all part of the universe. It is, simply, everything.

Though the universe may seem a strange place, it is not a distant one. Wherever you are right now, outer space is only 62 miles (100 kilometers) away. Day or night, whether you’re indoors or outdoors, asleep, eating lunch or dozing off in class, outer space is just a few dozen miles above your head. It’s below you too. About 8,000 miles (12,800 kilometers) below your feet — on the opposite side of Earth — lurks the unforgiving vacuum and radiation of outer space.

In fact, you’re technically in space right now. Humans say “out in space” as if it’s there and we’re here, as if Earth is separate from the rest of the universe. But Earth is a planet, and it’s in space and part of the universe just like the other planets. It just so happens that things live here and the environment near the surface of this particular planet is hospitable for life as we know it. Earth is a tiny, fragile exception in the cosmos. For humans and the other things living on our planet, practically the entire cosmos is a hostile and merciless environment.

How old is the universe?

The universe, on the other hand, appears to be about 13.8 billion years old. Scientists arrived at that number by measuring the ages of the oldest stars and the rate at which the universe expands. They also measured the expansion by observing the Doppler shift in light from galaxies, almost all of which are traveling away from us and from each other. The farther the galaxies are, the faster they’re traveling away. One might expect gravity to slow the galaxies’ motion from one another, but instead they’re speeding up and scientists don’t know why. In the distant future, the galaxies will be so far away that their light will not be visible from Earth.

Put another way, matter, energy and everything in the universe (including space itself) was more compact last Saturday than it is today. The same can be said about any time in the past — last year, a million years ago, a billion years ago. But the past doesn’t go on forever.

By measuring the speed of galaxies and their distances from us, scientists have found that if we could go back far enough, before galaxies formed or stars began fusing hydrogen into helium, things were so close together and hot that atoms couldn’t form and photons had nowhere to go. A bit farther back in time, everything was in the same spot. Or really the entire universe (not just the matter in it) was one spot.

Don't spend too much time considering a mission to visit the spot where the universe was born, though, as a person cannot visit the place where the Big Bang happened. It's not that the universe was a dark, empty space and an explosion happened in it from which all matter sprang forth. The universe didn’t exist. Space didn’t exist. Time is part of the universe and so it didn’t exist. Time, too, began with the big bang. Space itself expanded from a single point to the enormous cosmos as the universe expanded over time.

What is the universe made of?

The universe contains all the energy and matter there is. Much of the observable matter in the universe takes the form of individual atoms of hydrogen, which is the simplest atomic element, made of only a proton and an electron (if the atom also contains a neutron, it is instead called deuterium). Two or more atoms sharing electrons is a molecule. Many trillions of atoms together is a dust particle. Smoosh a few tons of carbon, silica, oxygen, ice, and some metals together, and you have an asteroid. Or collect 333,000 Earth masses of hydrogen and helium together, and you have a Sun-like star.

For the sake of practicality, humans categorize clumps of matter based on their attributes. Galaxies, star clusters, planets, dwarf planets, rogue planets, moons, rings, ringlets, comets, meteorites, raccoons — they’re all collections of matter exhibiting characteristics different from one another but obeying the same natural laws.

Scientists have begun tallying those clumps of matter and the resulting numbers are pretty wild. Our home galaxy, the Milky Way, contains at least 100 billion stars, and the observable universe contains at least 100 billion galaxies. If galaxies were all the same size, that would give us 10 thousand billion billion (or 10 sextillion) stars in the observable universe.

But the universe also seems to contain a bunch of matter and energy that we can’t see or directly observe. All the stars, planets, comets, sea otters, black holes and dung beetles together represent less than 5 percent of the stuff in the universe. About 27 percent of the remainder is dark matter, and 68 percent is dark energy, neither of which are even remotely understood. The universe as we understand it wouldn’t work if dark matter and dark energy didn’t exist, and they’re labeled “dark” because scientists can’t seem to directly observe them. At least not yet.

How has our view of the universe changed over time?

Human understanding of what the universe is, how it works and how vast it is has changed over the ages. For countless lifetimes, humans had little or no means of understanding the universe. Our distant ancestors instead relied upon myth to explain the origins of everything. Because our ancestors themselves invented them, the myths reflect human concerns, hopes, aspirations or fears rather than the nature of reality.

Several centuries ago, however, humans began to apply mathematics, writing and new investigative principles to the search for knowledge. Those principles were refined over time, as were scientific tools, eventually revealing hints about the nature of the universe. Only a few hundred years ago, when people began systematically investigating the nature of things, the word “scientist” didn’t even exist (researchers were instead called “natural philosophers” for a time). Since then, our knowledge of the universe has repeatedly leapt forward. It was only about a century ago that astronomers first observed galaxies beyond our own, and only a half-century has passed since humans first began sending spacecraft to other worlds.

In the span of a single human lifetime, space probes have voyaged to the outer solar system and sent back the first up-close images of the four giant outermost planets and their countless moons; rovers wheeled along the surface on Mars for the first time; humans constructed a permanently crewed, Earth-orbiting space station; and the first large space telescopes delivered jaw-dropping views of more distant parts of the cosmos than ever before. In the early 21st century alone, astronomers discovered thousands of planets around other stars, detected gravitational waves for the first time and produced the first image of a black hole.

With ever-advancing technology and knowledge, and no shortage of imagination, humans continue to lay bare the secrets of the cosmos. New insights and inspired notions aid in this pursuit, and also spring from it. We have yet to send a space probe to even the nearest of the billions upon billions of other stars in the galaxy. Humans haven’t even explored all the worlds in our own solar system. In short, most of the universe that can be known remains unknown.

The universe is nearly 14 billion years old, our solar system is 4.6 billion years old, life on Earth has existed for maybe 3.8 billion years, and humans have been around for only a few hundred thousand years. In other words, the universe has existed roughly 56,000 times longer than our species has. By that measure, almost everything that’s ever happened did so before humans existed. So of course we have loads of questions — in a cosmic sense, we just got here.

Our first few decades of exploring our own solar system are merely a beginning. From here, just one human lifetime from now, our understanding of the universe and our place in it will have undoubtedly grown and evolved in ways we can today only imagine.

#Universe

[entertainmentnerdly]

Astronomers may have found an Earth-like exoplanet orbiting a sun-like star via /r/space https://ift.tt/2MAwdNg

#reddit #Astronomers may have found an Earth-like exoplanet orbiting a sun-like star #Space #the fin

[nasa]

The Stellar Buddy System

Our Sun has an entourage of planets, moons, and smaller objects to keep it company as it traverses the galaxy. But it’s still lonely compared to many of the other stars out there, which often come in pairs. These cosmic couples, called binary stars, are very important in astronomy because they can easily reveal things that are much harder to learn from stars that are on their own. And some of them could even host habitable planets!

The birth of a stellar duo

New stars emerge from swirling clouds of gas and dust that are peppered throughout the galaxy. Scientists still aren’t sure about all the details, but turbulence deep within these clouds may give rise to knots that are denser than their surroundings. The knots have stronger gravity, so they can pull in more material and the cloud may begin to collapse.

The material at the center heats up. Known as a protostar, it is this hot core that will one day become a star. Sometimes these spinning clouds of collapsing gas and dust may break up into two, three, or even more blobs that eventually become stars. That would explain why the majority of the stars in the Milky Way are born with at least one sibling.

Seeing stars

We can’t always tell if we’re looking at binary stars using just our eyes. They’re often so close together in the sky that we see them as a single star. For example, Sirius, the brightest star we can see at night, is actually a binary system (see if you can spot both stars in the photo above). But no one knew that until the 1800s.

Precise observations showed that Sirius was swaying back and forth like it was at a middle school dance. In 1862, astronomer Alvan Graham Clark used a telescope to see that Sirius is actually two stars that orbit each other.

But even through our most powerful telescopes, some binary systems still masquerade as a single star. Fortunately there are a couple of tricks we can use to spot these pairs too.

Since binary stars orbit each other, there’s a chance that we’ll see some stars moving toward and away from us as they go around each other. We just need to have an edge-on view of their orbits. Astronomers can detect this movement because it changes the color of the star’s light – a phenomenon known as the Doppler effect.

Stars we can find this way are called spectroscopic binaries because we have to look at their spectra, which are basically charts or graphs that show the intensity of light being emitted over a range of energies. We can spot these star pairs because light travels in waves. When a star moves toward us, the waves of its light arrive closer together, which makes its light bluer. When a star moves away, the waves are lengthened, reddening its light.

Sometimes we can see binary stars when one of the stars moves in front of the other. Astronomers find these systems, called eclipsing binaries, by measuring the amount of light coming from stars over time. We receive less light than usual when the stars pass in front of each other, because the one in front will block some of the farther star’s light.

Sibling rivalry

Twin stars don’t always get along with each other – their relationship may be explosive! Type Ia supernovae happen in some binary systems in which a white dwarf – the small, hot core left over when a Sun-like star runs out of fuel and ejects its outer layers – is stealing material away from its companion star. This results in a runaway reaction that ultimately detonates the thieving star. The same type of explosion may also happen when two white dwarfs spiral toward each other and collide. Yikes!

Scientists know how to determine how bright these explosions should truly be at their peak, making Type Ia supernovae so-called standard candles. That means astronomers can determine how far away they are by seeing how bright they look from Earth. The farther they are, the dimmer they appear. Astronomers can also look at the wavelengths of light coming from the supernovae to find out how fast the dying stars are moving away from us.

Studying these supernovae led to the discovery that the expansion of the universe is speeding up. Our Nancy Grace Roman Space Telescope will scan the skies for these exploding stars when it launches in the mid-2020s to help us figure out what’s causing the expansion to accelerate – a mystery known as dark energy.

Spilling stellar secrets

Astronomers like finding binary systems because it’s a lot easier to learn more about stars that are in pairs than ones that are on their own. That’s because the stars affect each other in ways we can measure. For example, by paying attention to how the stars orbit each other, we can determine how massive they are. Since heavier stars burn hotter and use up their fuel more quickly than lighter ones, knowing a star’s mass reveals other interesting things too.

By studying how the light changes in eclipsing binaries when the stars cross in front of each other, we can learn even more! We can figure out their sizes, masses, how fast they’re each spinning, how hot they are, and even how far away they are. All of that helps us understand more about the universe.

Tatooine worlds

Thanks to observatories such as our Kepler Space Telescope, we know that worlds like Luke Skywalker’s home planet Tatooine in “Star Wars” exist in real life. And if a planet orbits at the right distance from the two stars, it could even be habitable (and stay that way for a long time).

In 2019, our Transiting Exoplanet Survey Satellite (TESS) found a planet, known as TOI-1338 b, orbiting a pair of stars. These worlds are tricker to find than planets with only one host star, but TESS is expected to find several more!

Want to learn more about the relationships between stellar couples? Check out this Tumblr post: https://nasa.tumblr.com/post/190824389279/cosmic-couples-and-devastating-breakups

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

#NASA #stars #may the fourth be with you #Star Wars Day #binary stars #tattooine #TESS #Roman Space Telescope #space #Kepler #science #space facts #sirius #dark energy #supernova #astronomy #exoplanets

[spacetimewithstuartgary]

Exoplanet may reveal secrets about the edge of habitability How close can a rocky planet be to a star, and still sustain water and life? A recently discovered exoplanet may be key to solving that mystery. “Super-Earth” LP 890-9c (also named SPECULOOS-2c) is providing important insights about conditions at the inner edge of a star’s habitable zone and why Earth and Venus developed so differently, according to new research led by Lisa Kaltenegger, associate professor of astronomy at Cornell University. Her team found LP 890-9c, which orbits close to the inner edge of its solar system’s habitable zone, would look vastly different depending on whether it still had warm oceans, a steam atmosphere, or if it had lost its water – assuming it once had oceans like Earth’s. “Looking at this planet will tell us what’s happening on this inner edge of the habitable zone – how long a rocky planet can maintain habitability when it starts to get hot,” Kaltenegger said. “It will teach us something fundamental about how rocky planets evolve with increasing starlight, and about what will one day happen to us and Earth.” Kaltenegger is the lead author of “Hot Earth or Young Venus? A Nearby Transiting Rocky Planet Mystery,” published in Monthly Notices of the Royal Astronomical Society: Letters. LP 890-9c is one of two super-Earths orbiting a red dwarf star located 100 light years from Earth, researchers announced last year. They said liquid water or an atmosphere rich in water vapor was possible on LP 890-9c, which is about 40% larger than Earth and circles the small, cool star in 8.5 days. Those criteria suggested it to be one of the best targets for JWST to study among the known, potentially habitable terrestrial planets, in addition to the TRAPPIST-1 system. The team’s models are the first to detail differences in the chemical signatures generated by rocky planets near the habitable zone’s interior boundary, based on variables including the planet’s size, mass, chemical makeup, surface temperature and pressure, atmospheric height and cloud cover. The calculations were key to estimating how much time JWST would need to confirm the basic composition of an atmosphere – if there is one. The models span several scenarios thought to reflect stages of rocky planets’ evolution, ranging from a “hot Earth” where life might still be possible, to a desolate Venus featuring a carbon dioxide atmosphere. In between are phases Earth is expected to experience as the sun grows brighter and hotter with age, causing the oceans to gradually evaporate and fill the atmosphere with steam before boiling off entirely. How long those processes might take is unknown, and the astronomers say LP 890-9c provides a rare opportunity to explore that evolution. “This planet is the first target where we can test these different scenarios,” Kaltenegger said. “If it’s still a hotter Earth – hot, but with liquid water and conditions for life – then the timeline is slower than we thought. If we see that it’s already a full-blown Venus, then the water gets lost fast.” It’s possible that LP 890-9c has no atmosphere and hosts no life, or that it resembles a Venus with thick clouds that would block light from reflecting and thus yield little information. Deeper investigation promises to provide valuable clues, Kaltenegger said. “We don’t know what this planet on the edge of habitability could be like, so we have to look,” she said. “This is what real exploration is about.”

#space #science #Astronomy #physics #news #exoplanets

[mysticstronomy]

ASTRONOMERS SEE SIGNS OF A NEW WORLD OUTSIDE MILKY WAY FOR FIRST TIME!!

Blog# 157

Wednesday, January 12th, 2022

Welcome back,

Signs of a planet transiting a star outside of the Milky Way galaxy may have been detected for the first time. This intriguing result, using NASA’s Chandra X-ray Observatory, opens up a new window to search for exoplanets at greater distances than ever before.

The possible exoplanet candidate is located in the spiral galaxy Messier 51 (M51), also called the Whirlpool Galaxy because of its distinctive profile.

Exoplanets are defined as planets outside of our Solar System. Until now, astronomers have found all other known exoplanets and exoplanet candidates in the Milky Way galaxy, almost all of them less than about 3,000 light-years from Earth. An exoplanet in M51 would be about 28 million light-years away, meaning it would be thousands of times farther away than those in the Milky Way.

“We are trying to open up a whole new arena for finding other worlds by searching for planet candidates at X-ray wavelengths, a strategy that makes it possible to discover them in other galaxies,” said Rosanne Di Stefano of the Center for Astrophysics | Harvard & Smithsonian (CfA) in Cambridge, Massachusetts, who led the study, which was published today in Nature Astronomy.

This new result is based on transits, events in which the passage of a planet in front of a star blocks some of the star's light and produces a characteristic dip. Astronomers using both ground-based and space-based telescopes – like those on NASA's Kepler and TESS missions – have searched for dips in optical light, electromagnetic radiation humans can see, enabling the discovery of thousands of planets.

Di Stefano and colleagues have instead searched for dips in the brightness of X-rays received from X-ray bright binaries. These luminous systems typically contain a neutron star or black hole pulling in gas from a closely orbiting companion star. The material near the neutron star or black hole becomes superheated and glows in X-rays.

Because the region producing bright X-rays is small, a planet passing in front of it could block most or all of the X-rays, making the transit easier to spot because the X-rays can completely disappear. This could allow exoplanets to be detected at much greater distances than current optical light transit studies, which must be able to detect tiny decreases in light because the planet only blocks a tiny fraction of the star.

The team used this method to detect the exoplanet candidate in a binary system called M51-ULS-1, located in M51. This binary system contains a black hole or neutron star orbiting a companion star with a mass about 20 times that of the Sun. The X-ray transit they found using Chandra data lasted about three hours, during which the X-ray emission decreased to zero.

Based on this and other information, the researchers estimate the exoplanet candidate in M51-ULS-1 would be roughly the size of Saturn, and orbit the neutron star or black hole at about twice the distance of Saturn from the Sun.

While this is a tantalizing study, more data would be needed to verify the interpretation as an extragalactic exoplanet. One challenge is that the planet candidate’s large orbit means it would not cross in front of its binary partner again for about 70 years, thwarting any attempts for a confirming observation for decades.

Originally published on exoplanets.nasa.gov

COMING UP!!

(Saturday, January 15th, 2022)

“ASTRONOMERS SEE SIGNS OF A NEW WORLD OUTSIDE MILKY WAY FOR FIRST TIME!! PT.2”

#astronomyclub #astronomylover #astronomyfacts #Astronomy #outer space #spacecraft #spaceX #space #atmosphere #Sunspot #universe #alternate universe #white universe #Parallel Universe #my universe #antimatter #Dark Matter #strange matter #astrophotography #astrophysics