Exoplanets – worlds of other suns

weatheriscool
Posts: 12971
Joined: Sun May 16, 2021 6:16 pm

Re: Exoplanets – worlds of other suns

Post by weatheriscool »

New insights into seasons on a planet outside our solar system
https://phys.org/news/2022-01-insights- ... solar.html
by McGill University

Imagine being in a place where the winds are so strong that they move at the speed of sound. That's just one aspect of the atmosphere on XO-3b, one of a class of exoplanets (planets outside our solar system), known as hot Jupiters. The eccentric orbit of the planet also leads to seasonal variations hundreds of times stronger than what we experience on Earth. In a recent paper, a McGill-led research team, provides new insight into what seasons looks like on a planet outside our solar system. The researchers also suggest that the oval orbit, extremely high surface temperatures (2,000 degrees C- hot enough to vaporize rock) and "puffiness" of XO-3b reveal traces of the planet's history. The findings will potentially advance both the scientific understanding of how exoplanets form and evolve and give some context for planets in our own solar system.

Hot Jupiters are massive, gaseous worlds like Jupiter, that orbit closer to their parent stars than Mercury is to the Sun. Though not present in our own solar system, they appear to be common throughout the galaxy. Despite being the most studied type of exoplanet, major questions remain about how they form. Could there be subclasses of hot Jupiters with different formation stories? For example, do these planets take shape far from their parent stars—at a distance where it's cold enough for molecules such as water to become solid—or closer. The first scenario fits better with theories about how planets in our own solar system are born, but what would drive these types of planets to migrate so close to their parent stars remains unclear.

To test those ideas, the authors of a recent McGill-led study used data from NASA's retired Spitzer Space Telescope to look at the atmosphere of exoplanet XO-3b. They observed eccentric seasons and measured wind speeds on the planet by obtaining a phase curve of the planet as it completed a full revolution about its host star.
weatheriscool
Posts: 12971
Joined: Sun May 16, 2021 6:16 pm

Re: Exoplanets – worlds of other suns

Post by weatheriscool »

Astronomers find evidence for a second supermoon beyond our solar system
https://phys.org/news/2022-01-astronome ... solar.html
by Columbia University
Astronomers have reported a second, super-sized moon orbiting a Jupiter-sized planet beyond our solar system. If confirmed, the sighting could mean that exomoons are as common in the universe as exoplanets, and that big or small, such moons are a feature of planetary systems. But it could be a long wait. The first-ever sighting of an exomoon four years ago is still awaiting confirmation, and verification of this newest candidate could be as equally long and contentious.

The discovery, published in Nature Astronomy, was led by David Kipping and his Cool Worlds Lab at Columbia University, which reported the first exomoon candidate in 2017.

"Astronomers have found more than 10,000 exoplanet candidates so far, but exomoons are far more challenging," said Kipping, who has spent the last decade hunting for exomoons. "They are terra incognita."

The team spotted the giant exomoon candidate orbiting the planet Kepler 1708b, a world 5,500 light-years from Earth in the direction of the Cygna and Lyra constellations. This new candidate is about a third smaller than the Neptune-sized moon that Kipping and his colleagues earlier found orbiting a similar Jupiter-sized planet, Kepler 1625b.

Both supermoon candidates are likely made of gas that has piled up under the gravitational pull caused by their enormous size, said Kipping. If one astronomer's hypothesis is correct, the moons may have even started life as planets, only to be pulled into the orbit of an even bigger planet like Kepler 1625b or 1708b.
weatheriscool
Posts: 12971
Joined: Sun May 16, 2021 6:16 pm

Re: Exoplanets – worlds of other suns

Post by weatheriscool »

weatheriscool
Posts: 12971
Joined: Sun May 16, 2021 6:16 pm

Re: Exoplanets – worlds of other suns

Post by weatheriscool »

Water vapor detected on a 'super Neptune'
https://phys.org/news/2022-01-vapor-super-neptune.html
by Pat Brennan, NASA
The recently discovered planet TOI-674 b, a bit bigger than Neptune and orbiting a red-dwarf star about 150 light-years away, is a member of an exclusive club: Exoplanets, or planets around other stars, known to have water vapor in their atmospheres. Many questions remain, such as how much water vapor its atmosphere holds. But TOI-674 b's atmosphere is far easier to observe than those of many exoplanets, making it a prime target for deeper investigation.

The planet's distance, size and relationship to its star make it especially accessible to spaceborne telescopes. At 150 light-years, it's considered "nearby" in astronomical terms. The star itself, relatively cool and less than half as big around as our Sun, can't be seen from Earth with the naked eye, but this too translates into an advantage for astronomers. As the comparatively large planet—in a size-class known as "super Neptune"—crosses the face of its smallish star, starlight shining through its atmosphere can be more easily analyzed by our telescopes. Those equipped with special instruments called spectrographs—including the just-launched James Webb Space Telescope—can spread this light into a spectrum, revealing which gases are present in the planet's atmosphere.
User avatar
Kevin_Hall
Posts: 7
Joined: Mon Jan 17, 2022 6:25 pm

Re: Exoplanets – worlds of other suns

Post by Kevin_Hall »

A group of astronomers and citizen scientists has uncovered a hidden planet the size of Jupiter in a distant solar system, and they should get the chance to see it again soon.
"There's a lot of science motivation," behind studying long-orbit exoplanets, Dalba added. "We can ask questions like, 'Do short and long orbit exoplanets form differently or evolve differently? How do they change over time?'"

TOI-2180 b is roughly the same size as Jupiter. But it's almost three times more massive; the planet contains roughly 105 Earth masses' worth of elements heavier than hydrogen and helium, according to a release issued by the University of New Mexico, the home institution of discovery team member Diana Dragomir. This density difference could indicate that the planet formed differently from Jupiter.
https://www.space.com/hidden-exoplanet- ... scientists
"Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world", - Einstein.
weatheriscool
Posts: 12971
Joined: Sun May 16, 2021 6:16 pm

Re: Exoplanets – worlds of other suns

Post by weatheriscool »

NASA's TESS hits milestone of 5,000 exoplanet candidates
https://phys.org/news/2022-01-nasa-tess ... dates.html
by Massachusetts Institute of Technology
The catalog of planet candidates found with NASA's Transiting Exoplanet Survey Satellite (TESS) recently passed 5,000 TOIs, or TESS Objects of Interest.

The catalog has been growing steadily since the start of the mission in 2018, and the batch of TOIs boosting the catalog to over 5,000 come mostly from the Faint Star Search led by MIT postdoc Michelle Kunimoto.

Kunimoto reflects, "This time last year, TESS had found just over 2,400 TOIs. Today, TESS has reached more than twice that number—a huge testament to the mission and all the teams scouring the data for new planets. I'm excited to see thousands more in the years to come!"

Now in its extended mission, TESS is observing the Northern Hemisphere and ecliptic plane, including regions of the sky previously observed by the Kepler and K2 missions. The TOIs added in late December are from the third year of the TESS mission, which ran from July 2020 to June 2021. TESS re-observed the sky visible in the Earth's Southern Hemisphere, revisiting stars it had first observed at the mission's start in 2018.
User avatar
caltrek
Posts: 6509
Joined: Mon May 17, 2021 1:17 pm

Re: Exoplanets – worlds of other suns

Post by caltrek »

Extreme Exoplanet Has a Complex and Exotic Atmosphere
January 28, 2022

https://www.eurekalert.org/news-releases/941663

Introduction:
(EurekAlert) An international team including researchers from the University of Bern and the University of Geneva as well as the National Centre of Competence in Research (NCCR) PlanetS analyzed the atmosphere of one of the most extreme known planets in great detail. The results from this hot, Jupiter-like planet that was first characterized with the help of the CHEOPS space telescope, may help astronomers understand the complexities of many other exoplanets – including Earth-like planets.

The atmosphere of Earth is not a uniform envelope but consists of distinct layers that each have characteristic properties. The lowest layer that spans from sea level beyond the highest mountain peaks, for example – the troposphere –, contains most of the water vapour and is thus the layer in which most weather phenomena occur. The layer above it – the stratosphere – is the one that contains the famous ozone layer that shields us from the Sun's harmful ultraviolet radiation.

In a new study that appeared in the journal Nature Astronomy, an international team of researchers led by the University of Lund show for the first time that the atmosphere of one of the most extreme known planets may have similarly distinct layers as well – albeit with very different characteristics.

An exotic cocktail for an atmosphere

WASP-189b is a planet outside our own solar system, located 322 light years from Earth. Extensive observations with the CHEOPS space telescope in 2020 revealed among other things that the planet is 20 times closer to its host star than Earth is to the Sun and has a daytime temperature of 3200 degrees Celsius. More recent investigations with the HARPS spectrograph at the La Silla Observatory in Chile now for the first time allowed the researchers to take a closer look at the atmosphere of this Jupiter-like planet.
Don't mourn, organize.

-Joe Hill
weatheriscool
Posts: 12971
Joined: Sun May 16, 2021 6:16 pm

Re: Exoplanets – worlds of other suns

Post by weatheriscool »

Validation of 13 Hot and Potentially Terrestrial TESS Planets
https://iopscience.iop.org/article/10.3 ... 881/ac4334
The James Webb Space Telescope will be able to probe the atmospheres and surface properties of hot, terrestrial planets via emission spectroscopy. We identify 18 potentially terrestrial planet candidates detected by the Transiting Exoplanet Survey Satellite (TESS) that would make ideal targets for these observations. These planet candidates cover a broad range of planet radii (Rp ∼ 0.6–2.0R⊕) and orbit stars of various magnitudes (Ks = 5.78–10.78, V = 8.4–15.69) and effective temperatures (Teff ∼ 3000–6000 K). We use ground-based observations collected through the TESS Follow-up Observing Program (TFOP) and two vetting tools—DAVE and TRICERATOPS—to assess the reliabilities of these candidates as planets. We validate 13 planets: TOI-206 b, TOI-500 b, TOI-544 b, TOI-833 b, TOI-1075 b, TOI-1411 b, TOI-1442 b, TOI-1693 b, TOI-1860 b, TOI-2260 b, TOI-2411 b, TOI-2427 b, and TOI-2445 b. Seven of these planets (TOI-206 b, TOI-500 b, TOI-1075 b, TOI-1442 b, TOI-2260 b, TOI-2411 b, and TOI-2445 b) are ultra-short-period planets. TOI-1860 is the youngest (133 ± 26 Myr) solar twin with a known planet to date. TOI-2260 is a young (321 ± 96 Myr) G dwarf that is among the most metal-rich ([Fe/H] = 0.22 ± 0.06 dex) stars to host an ultra-short-period planet. With an estimated equilibrium temperature of ∼2600 K, TOI-2260 b is also the fourth hottest known planet with Rp < 2 R⊕.
weatheriscool
Posts: 12971
Joined: Sun May 16, 2021 6:16 pm

Re: Exoplanets – worlds of other suns

Post by weatheriscool »

A temperate sub-Neptune at TOI-1759

TOI-1759 b: a transiting sub-Neptune around a low mass star characterized with SPIRou and TESS
https://arxiv.org/abs/2202.01259

A transiting, temperate mini-Neptune orbiting the M dwarf TOI-1759 unveiled by TESS
https://arxiv.org/abs/2202.01240
weatheriscool
Posts: 12971
Joined: Sun May 16, 2021 6:16 pm

Re: Exoplanets – worlds of other suns

Post by weatheriscool »

Final moments of planetary remnants seen for first time
https://phys.org/news/2022-02-moments-p ... nants.html
by University of Warwick
The moment that debris from destroyed planets impacts the surface of a white dwarf star has been observed for the first time by astronomers at the University of Warwick.

They have used X-rays to detect the rocky and gaseous material left behind by a planetary system after its host star dies as it collides and is consumed within the surface of the star.

Published today (9 February) in the journal Nature, the results are the first direct measurement of the accretion of rocky material onto a white dwarf, and confirm decades of indirect evidence of accretion in over a thousand stars so far. The observed event occurred billions of years after the formation of the planetary system.
Post Reply