NASA | JPL-Caltech | Spitzer | 2015 Jun 11
[img3="Planets having atmospheres rich in helium may be common in our galaxy,They wouldn't float like balloons or give you the chance to talk in high, squeaky voices, but planets with helium skies may constitute an exotic planetary class in our Milky Way galaxy. Researchers using data from NASA's Spitzer Space Telescope propose that warm Neptune-size planets with clouds of helium may be strewn about the galaxy by the thousands.
according to a new theory based on data from NASA's Spitzer Space Telescope.
(Credit: NASA/JPL-Caltech)"]http://www.spitzer.caltech.edu/uploaded ... 08_Med.jpg[/img3][hr][/hr]
"We don't have any planets like this in our own solar system," said Renyu Hu, NASA Hubble Fellow at the agency's Jet Propulsion Laboratory in Pasadena, California, and lead author of a new study on the findings accepted for publication in the Astrophysical Journal. "But we think planets with helium atmospheres could be common around other stars."
Prior to the study, astronomers had been investigating a surprising number of so-called warm Neptunes in our galaxy. NASA's Kepler space telescope has found hundreds of candidate planets that fall into this category. They are the size of Neptune or smaller, with tight orbits that are closer to their stars than our own sizzling Mercury is to our sun. These planets reach temperatures of more than 1,340 degrees Fahrenheit (1,000 Kelvin), and orbit their stars in as little as one or two days. ...
Helium Atmospheres on Warm Neptune- and Sub-Neptune-Sized Exoplanets and Applications to GJ 436 b - Renyu Hu, Sara Seager, Yuk L. Yung
- arXiv.org > astro-ph > arXiv:1505.02221 > 09 May 2015