NASA’s Newest Planet Hunting Satellite TESS Spots First Confirmed Exoplanets

TESS confirmed exoplanet

Three months into its observations and TESS was already finding confirmed exoplanets. Another 280+ potential exoplanets are getting follow-up observations from telescopes back on Earth.

Unfortunately, the three confirmed exoplanets wouldn’t make great vacation spots for us.

First up is Pi Mensae c. It’s about twice the size of Earth and swings around its host star (Pi Mensae) every six days. Pi Mensae can be seen in the constellation Mensa with the unaided eye according to NASA. That’ll make the otherwise typical star a fun target for my telescope next time I drag it out.

Pi Mensae c makes it two confirmed planets orbiting Pi Mensae. The other is dubbed Pi Mensae b and takes a long, irregular trek around the star.

Chelsea Huang, from MIT’s Kavli Institute for Astrophysics and Space Research, explains how this second exoplanet discovery could help shed light on planetary formation:

“In contrast, the new planet, called Pi Mensae c, has a circular orbit close to the star, and these orbital differences will prove key to understanding how this unusual system formed.”

The second confirmed planet, LHS 3884b, is more similar in size to Earth at just 1.3 times the size. But the similarities stop there. It’s a rocky planet orbiting a cool M-type dwarf star at only one-fifth the size of our Sun. But a super-tight orbit of just 11 hours means that parts of the planet’s rocky surface on the daytime side could be made up of pools of lava.

The last confirmed planet is HD21749b. It clocks in at three times Earth’s size and 23 times its mass, and orbits every 36 days with its surface sitting at a balmy 300 degrees Fahrenheit.

“This planet has a greater density than Neptune, but it isn’t rocky. It could be a water planet or have some other type of substantial atmosphere,” says Diana Dragomir, lead author on the paper announcing the discovery.

A second exoplanet may also be in the same star system, but we’ll have to wait for follow-up observations to confirm it. If confirmed, this exoplanet would be the smallest TESS has seen so far at about the size of Earth.

TESS is still in the early parts of its two-year primary mission. During this time, it’ll look for as many worlds as it can find orbiting nearby stars. 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. Six supernovae were spotted by TESS between July 25 and August 22, 2018.

“Some of the most interesting science occurs in the early days of a supernova, which has been very difficult to observe before TESS,” said Michael Fausnaugh, a TESS researcher. “NASA’s Kepler space telescope caught six of these events as they brightened during its first four years of operations. TESS found as many in its first month.”

TESS is halfway through its first-year of observations. Once completed, astronomers should have a healthy catalog of more than 10,000 exoplanets to sift through.

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