Exoplanets – worlds of other suns

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weatheriscool
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The worlds next door: Looking for habitable planets around Alpha Centauri
https://phys.org/news/2021-11-worlds-do ... alpha.html
by University of Sydney
Could life exist around our nearest stellar neighbors? Led by the University of Sydney and supported by the Breakthrough Initiatives, NASA's Jet Propulsion Laboratory and Saber Astronautics, this project aims to find out.

A mission to discover new planets potentially capable of sustaining life around Earth's nearest neighbor, Alpha Centauri, was announced today.

The proposed telescope project will look for planets in the 'Goldilocks' zone around the star system just four light years away, where temperatures could allow for liquid surface water on rocky planets.

Work on the project began in April of this year. Scientists from the University of Sydney, in partnership with the Breakthrough Initiatives in California, Saber Astronautics in Australia and NASA's Jet Propulsion Laboratory, have named the project TOLIMAN, the Arabic-derived name for Alpha Centauri from antiquity.

"Our nearest stellar neighbors—the Alpha Centauri and Proxima Centauri systems—are turning out to be extraordinarily interesting," said Dr. Pete Worden, Executive Director of the Breakthrough Initiatives. "The TOLIMAN mission will be a huge step towards finding out if planets capable of supporting life exist there."
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Re: Exoplanets – worlds of other suns

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A highly mutually-inclined, compact warm-Jupiter system KOI-984?
https://arxiv.org/abs/2111.09668
The discovery of a population of close-orbiting giant planets (≤ 1 au) has raised a number of questions about their origins and dynamical histories. These issues have still not yet been fully resolved, despite over 20 years of exoplanet detections and a large number of discovered exoplanets. In particular, it is unclear whether warm Jupiters (WJs) form in situ, or whether they migrate from further outside and are even currently migrating to form hot Jupiters (HJs). Here, we report the possible discovery and characterization of the planets in a highly mutually-inclined (Imut≃45∘), compact two-planet system (KOI-984), in which the newly discovered warm Jupiter KOI-984c is on a 21.5-day, moderately eccentric (e≃0.4) orbit, in addition to a previously known 4.3-day planet candidate KOI-984b. Meanwhile, the orbital configuration of a moderately inclined (Imut≃15∘), low-mass (mc≃24M⊕;Pb≃8.6 days) perturbing planet near 1:2 mean motion resonace with KOI-984b could also well reproduce observed transit timing variations and transit duration variations of KOI-984b. Such an eccentric WJ with a close-in sibling would pose a challenge to the proposed formation and migration mechanisms of WJs, if the first scenario is supported with more evidences in near future; this system with several other well-measured inclined WJ systems (e.g., Kepler-419 and Kepler-108) may provide additional clues for the origin and dynamical histories of WJs.
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Re: Exoplanets – worlds of other suns

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Water Found in Habitable Super-Earth’s Atmosphere for First Time
by Ignat

Astronomers have discovered water vapor in the atmosphere of a super-Earth exoplanet orbiting within its star’s habitable zone. The discovery suggests that liquid water could exist on the rocky world’s surface, possibly forming a global ocean.

The discovery, made with NASA’s Hubble Space Telescope, is the first detection of water vapor in the atmosphere of such a planet. Because the planet, dubbed K2-18 b, is likely to have a temperature similar to Earth, the newly discovered water vapor makes it one of the most promising candidates for follow-up studies with next-generation space telescopes.

“This is the only planet right now that we know outside the solar system that has the correct temperature to support water, it has an atmosphere, and it has water in it, making this planet the best candidate for habitability that we know right now,” lead author Angelos Tsiaras, an astronomer at University College London, said in a press conference.
https://ilovetheuniverse.com/water-foun ... A0JCoogJvs
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Re: Exoplanets – worlds of other suns

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weatheriscool wrote: Sat Nov 20, 2021 7:40 am Water Found in Habitable Super-Earth’s Atmosphere for First Time
by Ignat

Astronomers have discovered water vapor in the atmosphere of a super-Earth exoplanet orbiting within its star’s habitable zone. The discovery suggests that liquid water could exist on the rocky world’s surface, possibly forming a global ocean.

The discovery, made with NASA’s Hubble Space Telescope, is the first detection of water vapor in the atmosphere of such a planet. Because the planet, dubbed K2-18 b, is likely to have a temperature similar to Earth, the newly discovered water vapor makes it one of the most promising candidates for follow-up studies with next-generation space telescopes.

“This is the only planet right now that we know outside the solar system that has the correct temperature to support water, it has an atmosphere, and it has water in it, making this planet the best candidate for habitability that we know right now,” lead author Angelos Tsiaras, an astronomer at University College London, said in a press conference.
https://ilovetheuniverse.com/water-foun ... A0JCoogJvs
Old study from two years ago.
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Re: Exoplanets – worlds of other suns

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New deep learning method adds 301 planets to Kepler's total count

by Jet Propulsion Laboratory
Over 4,5000 planets have been found around other stars, but scientists expect that our galaxy contains millions of planets. There are multiple methods for detecting these small, faint bodies around much larger, bright stars. Credit: NASA/JPL-Caltech

Scientists recently added a whopping 301 newly validated exoplanets to the total exoplanet tally. The throng of planets is the latest to join the 4,569 already validated planets orbiting a multitude of distant stars. How did scientists discover such a huge number of planets, seemingly all at once? The answer lies with a new deep neural network called ExoMiner.

Deep neural networks are machine learning methods that automatically learn a task when provided with enough data. ExoMiner is a new deep neural network that leverages NASA's Supercomputer, Pleiades, and can distinguish real exoplanets from different types of imposters, or "false positives." Its design is inspired by various tests and properties human experts use to confirm new exoplanets. And it learns by using past confirmed exoplanets and false positive cases.
https://phys.org/news/2021-11-deep-meth ... total.html
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Re: Exoplanets – worlds of other suns

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HATS-74Ab, HATS-75b, HATS-76b and HATS-77b: Four Transiting Giant Planets around K and M Dwarfs
https://arxiv.org/abs/2112.01928
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Re: Exoplanets – worlds of other suns

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New Planet Discovered in the Massive b Centauri Two-star System
by Dustin Manduffie
December 8, 2021

https://www.courthousenews.com/new-plan ... ar-system/

Introduction:
(Courthouse News) — Scientists with the European Southern Observatory discovered a planet in the hottest and most massive planet-hosting star system ever recorded.

The two-star system where the planet is located, known as HIP 71865, or b Centauri, sits within the constellation Centaurus about 325-light years from Earth.

At six times the mass of our own sun, the system is so massive, and so hot, that until being photographed by the ESO’s Very Large Telescope, many experts didn’t believe a planet could exist there. The new discovery shows that it is possible; the planet was found orbiting one of the system’s two stars at around 100 times the distance between Jupiter and the sun.

A team of astronomers from across Europe described the newly identified planet in a study published Wednesday in the journal Nature. See also:
(https://www.eurekalert.org/news-releases/936966? ).
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Re: Exoplanets – worlds of other suns

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TESS Finds a New Mars-Sized Planet (With the Density of Mercury)
by Evan Gough
December 8, 2021

https://www.universetoday.com/153610/te ... ore-153610

Introduction:
(Universe Today) Some planets orbit their stars so closely that they have extremely high surface temperatures and extremely rapid orbits. Most of the ones astronomers have found are Hot Jupiters— planets in the size range of Jupiter and with similar compositions as Jupiter. Their size and proximity to their star make them easier to spot using the transit method.

But there’s another type of planet that also orbits very close to their stars and has extremely high surface temperatures. They’re small, rocky, and they orbit their star in less than 24 hours. They’re called ultra-short-period (USP) planets and TESS found one that orbits its star in only eight hours.

And the planet’s density is almost equivalent to pure iron.

The planet orbits a red (M-type) dwarf star named GJ 367 about 31 light-years away. It’s named GJ 367b and it’s about 70% as large as Earth and about 55% as massive.
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Re: Exoplanets – worlds of other suns

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An Integrative Analysis of the HD 219134 Planetary System and the Inner Solar System: Extending DYNAMITE with Enhanced Orbital Dynamical Stability Criteria
https://arxiv.org/abs/2112.05337
Quote :
Planetary architectures remain unexplored for the vast majority of exoplanetary systems, even among the closest ones, with potentially hundreds of planets still ``hidden" from our knowledge. DYNAMITE is a powerful software package that can predict the presence and properties of these yet undiscovered planets. We have significantly expanded the integrative capabilities of DYNAMITE, which now allows for (i) planets of unknown inclinations alongside planets of known inclinations, (ii) population statistics and model distributions for the eccentricity of planetary orbits, and (iii) three different dynamical stability criteria. We demonstrate the new capabilities with a study of the HD 219134 exoplanet system consisting of four confirmed planets and two likely candidates, where five of the likely planets are Neptune-size or below with orbital periods less than 100 days. By integrating the known data for the HD 219134 planetary system with contextual and statistical exoplanet population information, we tested different system architecture hypotheses to determine their likely dynamical stability. Our results provide support for the planet candidates, and we predict at least two additional planets in this system. We also deploy DYNAMITE on analogs of the inner Solar System by excluding Venus or Earth from the input parameters to test DYNAMITE's predictive power. Our analysis finds the system remains stable while also recovering the excluded planets, demonstrating the increasing capability of DYNAMITE to accurately and precisely model the parameters of additional planets in multi-planet systems.
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Re: Exoplanets – worlds of other suns

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Kepler Bonus: Aperture Photometry Light Curves of EXBA Sources
https://arxiv.org/abs/2112.06683
Quote :
NASA's Kepler mission observed background regions across its field of view for more than three consecutive years using custom designed super apertures (EXBA masks). Since these apertures were designed to capture a region of the sky rather than single targets, the Kepler Science Data Processing pipeline produced Target Pixel Files, but did not produce light curves for the sources within these background regions. In this work we produce light curves for 9,327 sources observed in the EXBA masks. These light curves are generated using aperture photometry estimated from the instrument's Pixel Response Function (PRF) profile computed from Kepler's full-frame images. The PRF models enable the creation of apertures that follow the characteristic shapes of the PSF in the image and the computation of flux completeness and contamination metrics. The light curves are available at MAST as a High Level Science Product (kbonus-apexba). Alongside this dataset, we present kepler-apertures, a Python library to compute PRF models and use them to perform aperture photometry on Kepler-like data. Using light curves from the EXBA masks we found an exoplanet candidate around Gaia EDR3 2077240046296834304 consistent with a large planet companion with a 0.81RJ radius. Additionally, we report a catalog of 69 eclipsing binaries. We encourage the community to exploit this new dataset to perform in depth time domain analysis, such as eclipsing binaries demographic and others.
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