NASA's Transiting Exoplanet Survey Satellite (TESS) spied the mysterious planet right at the beginning of its mission scanning the skies for new planets: the third such discovery in its first three months of operation. The planet was named HD 21749b and revolves around a nearby dwarf star.
In 2017, Adina Feinstein, from the University of Chicago, and Makennah Bristow, from the University of North Carolina Asheville, who worked as interns with NASA astrophysicist Joshua Schlieder, were looking for evidence of transits, or the regular dimming of the star that occurs when an orbiting planet moves across its surface. NASA 2019 New Year Calendar Will Feature a Painting of 12-Year-Old Boy From Tamil Nadu, View Pic.
HD 21749b also has the longest orbital period of any exoplanet found within 100 light years of us (36 days), is about three times Earth's size but 23 times its mass - and, perhaps surprisingly, it's considered nearly chilly, as exoplanets go. Though "super-Earths" are often larger and more massive than our planet, HD 21749b is not thought to be rocky, meaning it's more like Neptune than Earth or Mars. But the gas that makes it up it is probably more dense than that of Uranus or Neptune. "But here we were lucky, and caught this one, and can now study it in more detail", Dragomir said. It is estimated to have an orbital period of 7.8 days, and could be the first Earth-sized exoplanet discovered by TESS outside our Solar System.
The discovery of the new world was presented at the American Astronomical Society meeting, which is taking place in Seattle this week. The NASA's Transiting Exoplanet Survey Satellite or TESS was launched int he April 2018 and has been scanning the space for exoplanets and astronomical objects.
"We've confirmed three planets so far, and there are so many more that are just waiting for telescope and people time to be confirmed", Dragomir said. With the launch of the James Webb Telescope, planet-hunters and scientists will be able to glean more information about TESS' discoveries and look closer for planets just like ours.
The HD 21749B is orbiting it's a star and completes the orbit in 33 days. But that won't be the only thing TESS will see as it stares into the same parts of the sky for months at a time. Their proximity to Earth will enable detailed characterization of the planets through follow-up observations from space- and ground-based telescopes.
The data that yielded the finds was collected between 25 July and 22 August previous year by the space telescope's four cameras.
This has already led to the discovery of two other planets, Pi Mensae c and LHS 3844b, back in September. Additional partners include Northrop Grumman, based in Falls Church, Virginia; NASA's Ames Research Center in California's Silicon Valley; the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts; MIT Lincoln Laboratory; and the Space Telescope Science Institute in Baltimore.