'Ultrahot Neptune' discovered around sunlike star
By Charles Q. Choi 7 hours ago
It's the first known exoplanet of its kind.
An artist's impression of the ultrahot Neptune exoplanet LTT 9779b.
(Image: © Ricardo Ramirez/University of Chile)
Astronomers have discovered a new type of alien world — the first known "ultrahot Neptune," a giant planet that orbits its star 60 times closer than Earth does the sun, a new study finds.
Previous research found that about 1 in 200 sunlike stars possesses a planet that circles its star so tightly that it orbits in less than one Earth day. Astronomers call these worlds "ultra-short-period planets." (In contrast, Earth takes slightly more than 365 days to circle the sun; Mercury, our sun's closest planet, takes less than 88 days to complete its year.)
All previously known ultra-short-period planets were either rocky planets less than twice Earth's width or so-called hot Jupiters, gas giants sizing in at more than 10 times Earth's diameter. Mysteriously, scientists haven't found many ultra-short-period planets of intermediate size, a phenomenon dubbed the "hot Neptune desert" because Neptune lies between Earth and Jupiter in size.
Now, scientists have discovered an exoplanet that sits right in the hot Neptune desert. But this planet is much hotter than any hot Neptune discovered yet, enough so for researchers to dub it "ultrahot."
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https://www.space.com/first-ultrahot-neptune-exoplanet-discovery-tess?utm_source=notification
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Santiago de Chile, Sep 21 (Prensa Latina) Chilean astronomers discovered a planet classed as 'the first Ultra Hot Neptune', 260 light years from Earth, according to a study published on Monday in the Nature Astronomy journal.
That celestial body, classified as LTT 9779, reaches temperatures of up to 1,700 degrees Celsius and is an exoplanet located in the Neptune Desert, an area with low planetary density and that, having bodies like the planet Neptune, allow scientists to study planetary atmospheres.
The planet's discoverers are James Jenkins, a scholar from the Department of Astronomy of the Faculty of Physical Sciences and Mathematics of the University of Chile, and Matias Diaz, a doctoral candidate in Astronomy at that center.
Both scientists studied the readings from the Transiting Exoplanet Survey Satellite, or TESS, in what was considered an 'unlikely' finding.
Jenkins explained that it is deemed an unlikely discovery because it is located in the Neptune Desert, where there are almost no planets and the existing ones have orbital periods of less than four days, and with masses and sizes similar to Neptune, which allows the investigation of its atmosphere.
He added that LTT 9779 has an atmosphere despite its closeness to the star it orbits and that it is very difficult to explain why this planet did not become a rock core, nor to find many more examples like this orbiting other stars as bright.
https://www.plenglish.com/index.php?o=rn&id=60006&SEO=chilean-astronomers-discover-a-unique-planet
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