One possible explanation for this ultrahot Neptune's thick atmosphere "is that the planet was originally much larger, maybe a gas giant like Jupiter, that migrated too close to the star," Jenkins said. One would expect ultrahot Neptunes "to lose their atmospheres very early due to the high-energy radiation received from the star, so for this planet we must think about more exotic types of formation scenarios," Jenkins said. The report noted "Mysteriously, LTT 9779 b still appears to possess a thick atmosphere, one consisting of nearly 10% of its mass, or equal to about 2.6 times Earth's mass, Jenkins said. Choi on Twitter Follow us on Twitter and on Facebook. 21 in the journal Nature Astronomy.įollow Charles Q. The scientists detailed their findings online Sept. "This means we will be hearing a lot more about this planet in the near future." The relatively bright nature of its star "means we can use ground-based and space-based instruments to investigate the planet in extreme detail," Jenkins added. In the future, Jenkins and his colleagues will analyze the light passing through this exoplanet's atmosphere "to search for what elements are in the atmosphere, what the temperature is around the planet, does the planet have clouds," he said.
After it lost much of its mass, the world then might have moved a little further away from the star, and ended up with a Neptune-like mass, he said. In this scenario, the star's gravity would have stripped off much of the exoplanet's atmosphere.
Mysteriously, LTT 9779 b still appears to possess a thick atmosphere, one consisting of nearly 10% of its mass, or equal to about 2.6 times Earth's mass, Jenkins said. Related: 'Smoking gun' planet: This Neptune-size alien world is evaporating in record time The researchers suggested it was unlikely that LTT 9779 b was made of pure rock or pure water - instead, they proposed a solid core surrounded by a hydrogen and helium atmosphere. The newfound exoplanet's average density is much like that of Neptune. This means its atmosphere "can be very different from just 'hot' planets," Jenkins said, "making them exciting laboratories to study the chemistries of planets." The ultrahot temperatures on LTT 9779 b can break molecules down to their constituent elements and ionize metals in its atmosphere. (A regular hot Neptune might only get as hot as about 2,240 degrees F (1,225 degrees C), study lead author James Jenkins, an astronomer at the University of Chile in Las Condes, told .) In a paper reporting the finding, scientists argued this exoplanet was not just a hot Neptune, but an ultrahot Neptune. LTT 9779 b zips around its star about every 19 hours, orbiting its star about 23 times closer than Mercury does the sun, with the star heating it to temperatures of about 3,100 degrees Fahrenheit (1,700 degrees Celsius). This newfound world, dubbed LTT 9779 b, has about 4.7 times Earth's diameter and 29 times Earth's mass. Followup observations with other telescopes helped confirm the existence of an exoplanet around this star. Astronomers used NASA's Transiting Exoplanet Survey Satellite (TESS) to analyze the bright, sunlike star LTT 9779, located about 260 light-years from Earth.
0 kommentar(er)
