TESS tagged posts

Astronomers discover a ‘Hot Neptune’ in a Tight Orbit

A dark planet, left, is shown in close orbit around its star, right; some of the planet's atmosphere is being blown outward by the star.
Artist’s concept of “hot Neptune” TOI-3261 b.
NASA/JPL-Caltech/K. Miller (Caltech/IPAC)

A Neptune-sized planet, TOI-3261 b, makes a scorchingly close orbit around its host star. Only the fourth object of its kind ever found, the planet could reveal clues as to how planets such as these form.

An international team of scientists used the NASA space telescope, TESS (the Transiting Exoplanet Survey Satellite), to discover the exoplanet, then made further observations with ground-based telescopes in Australia, Chile, and South Africa. The measurements placed the new planet squarely in the “hot Neptune desert”—a category of planets with so few members that their scarcity evokes a deserted landscape.

The team, led by astronomer Emma Nabbie of the University of Southern Queensland, pu...

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Formation of Super-Earths is Limited Near Metal-Poor Stars – New study may help the search for life beyond Earth

In a new study, astronomers report novel evidence regarding the limits of planet formation, finding that after a certain point, planets larger than Earth have difficulty forming near low-metallicity stars.

Using the sun as a baseline, astronomers can measure when a star formed by determining its metallicity, or the level of heavy elements present within it. Metal-rich stars or nebulas formed relatively recently, while metal-poor objects were likely present during the early universe.

Previous studies found a weak connection between metallicity rates and planet formation, noting that as a star’s metallicity goes down, so, too, does planet formation for certain planet populations, like sub-Saturns or sub-Neptunes.

Yet this work is the first to observe that under current theories...

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Astronomers find Surprising Ice World in the Habitable Zone with JWST data

Temperate exoplanet LHS 1140 b may be a world completely covered in ice (left) similar to Jupiter’s moon Europa or be an ice world with a liquid substellar ocean and a cloudy atmosphere (centre). LHS 1140 b is 1.7 times the size of our planet Earth (right) and is the most promising habitable zone exoplanet yet in our search for liquid water beyond the Solar System. Image credit: B. Gougeon/Université de Montréal

A team of astronomers has identified a temperate exoplanet as a promising super-Earth ice or water world.

The findings, led by Université de Montréal, show that the habitable zone exoplanet, LHS 1140 b, is not likely a mini-Neptune, a small so-called gas giant—large planets composed mostly of gas—with a thick hydrogen-rich atmosphere...

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TOI-1685 b is a Hot and Rocky Super-Earth Exoplanet, Observations find

TOI-1685 b is a hot and rocky super-Earth exoplanet, observations find
Best fit SED for TOI-1685 from VOSA. Colored points are photometric magnitudes from the Gaia, 2Mass, and WISE surveys, and magnitudes synthesized from spectrophotometrically calibrated Gaia DR3 Bp/Rp spectra into the photometric system of the OAJ JPAS and JPLUS surveys. Gray line depicts the model flux measurements. Credit: arXiv (2024). DOI: 10.48550/arxiv.2405.14895

An international team of astronomers has performed follow-up observations of a nearby alien world known as TOI-1685 b. Results of the observations, published May 21 on the pre-print server arXiv, indicate that TOI-1685 b is a hot and rocky alien world with an Earth-like density.

The so-called “super-Earths” are planets more massive than Earth but not exceeding the mass of Neptune...

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