Thirty-three light years. It’s nothing. Of course, it will be impossible to visit the two new planets discovered around the star called HD 260655, but make no mistake: the two new exoplanets discovered by astronomers are very close and therefore very important. And there could be more hidden planets.
An exoplanet is a planet orbiting another star beyond our solar system.
One of the closest known multiplanetary systems to ours, astronomers have discovered two rocky Earth-sized planets around HD 260655, a red dwarf star – by far the most common type of star in our galaxy of the Milky Way.
In the constellation Gemini (ironically called “the twins”), HD 260655 isn’t a famous star because it’s too dim to see with the naked eye, but it’s about the same distance from us as lots of bright stars you may be familiar with – like Pollux also in Gemini and Arcturus in Bootes.
That HD 260655 is a bright star and relatively close to us – and has orbiting planets – is something of a cosmic coup for astronomers. Indeed, although the James Webb Space Telescope may soon be pointed at distant exoplanets, it will only be able to reveal the properties of the atmospheres of nearby exoplanets.
Unfortunately, the two rocky planets around HD 260655 are unlikely to be habitable. Orbiting very close to their star, their surfaces must be too hot to contain liquid water.
“The two planets in this system are each considered among the best targets for atmospheric study due to their star’s brightness,” said Michelle Kunimoto, a post-doctoral fellow at the Kavli Institute for Astrophysics and Space Research. MIT and one of the leading scientists in the article. published and presented last week at the American Astronomical Society meeting. “Is there a volatile-rich atmosphere around these planets? And are there signs of water- or carbon-based species? These planets are fantastic testbeds for these explorations. said Kunimoto.
The planets were found using NASA’s $287 million Transiting Exoplanet Survey Satellite (TESS), which discovered about 5,000 planets and candidate planets in its first four years of observations. In total, TESS should find around 12,519 exoplanets.
The two exoplanets around HD 260655 have been detected as dips in the light coming from the host star, infallible proof that something is in transit. Archival data from ground-based telescopes in Hawaii and Spain helped confirm their existence.
The closest planet to the star – HD 260655b – orbits every 2.8 days and is about 1.2 times the size of Earth, twice as massive and slightly denser (it’s the density that’s crucial for the designation of exoplanets as being of rocky composition). On the surface, it’s 818º F. The outer planet, HD 260655c, orbits every 5.7 days and is 1.5 times the size of Earth, three times more massive than Earth, and slightly less dense. It’s 548º F on the surface.
The two planets are therefore outside the habitable zone, too close to their star and therefore too hot for liquid water to exist on their surface.
“But there could be more planets in the system,” said MIT team member Avi Shporer. “There are many multiplanetary systems hosting five or six planets, especially around small stars like this. Hopefully we’ll find more, and maybe there’ll be one in the living area.
I wish you clear skies and big eyes.