In the vicinity of our Solar System, about 53 light years away from us, NASA’s TESS, the famous exoplanets hunter launched about three months ago, spotted a new, exciting planet. The distant world that TESS identified is a sub-Neptune exoplanet by three times larger than the Earth. The particularity of this world, dubbed as HD 21749b, is that it is a gaseous planet of the density of water.
NASA’s TESS discovered the exoplanet on January 7th, and even though it’s by three times bigger than our planet, HD 21749b has a mass by 23 times higher than the Earth’s.
According to that data, this sub-Neptune exoplanet is a gaseous planet and not a rocky one like Earth or Mars, for example.
“We think this planet wouldn’t be as gaseous as Neptune or Uranus, which are mostly hydrogen and really puff. The planet likely has a density of water or a thick atmosphere,” explained the MIT researcher Diana Dragomir.
NASA’s TESS Exoplanets Hunter Detected A New Gaseous Planet
NASA’s TESS is the newest exoplanets hunter the US space agency placed in Earth’s orbit. TESS, also known as Transiting Exoplanet Survey Satellite, is using the transiting method to detect deep space planets. This technique implies observing a star and measuring interferences in the star’s light which indicates that a planet passed before the respective sun.
According to the MIT researchers, HD 21749b has a surface temperature of 300 degrees Fahrenheit which is a surprisingly cool temperature for how close the exoplanet is to its host star. Also, as the scientists reported, HD 21749 star is pretty much like our Sun, and the HD 21749b sub-Neptune exoplanet orbits it in 36 days.
“We know a lot about atmospheres of hot planets, but because it’s very hard to find small planets that orbit farther from their stars and are therefore cooler, we haven’t been able to learn much about these smaller, cooler planets,” concluded Diana Dragomir.