Our sun is a lonely wolf of a star, but out there in the wider universe, stars are often trapped in a dance with others and orbiting around each other. In such a three-star system, astronomers have just found an exoplanet.
It has the rather catchy name LTT 1445Ab, as it orbits the primary star of three red dwarfs that form the LTT 1445 system and are at a distance of about 22.5 light-years.
"When you stand on the surface of this planet there are three suns in the sky, but two of them are quite far away and look small, they are like two red, menacing eyes in the sky."
The researches Their team has submitted in the Astronomical Journal so we can assume that they will soon be peer reviewed.
The planet was discovered by TESS, NASA's Space Telescope, with which exoplanets can be found passing between us and their home star, recognizing the telltale dimming when the planet blocks a small percentage of the star's light.
and the tiny movements of the star as it is easily pulled from the pla Gravity of the network (detected with other telescopes) allows scientists to limit the size and mass of the planet.
The new planet reaches only 1.35 times the physical size of the earth. At this size, it packs 8.4 times the mass of the earth, so it's much denser than our home planet.
Although this size and mass place it firmly in the rocky category – such as Earth, Venus and Mars as opposed to gas or Ice Giants – and although there would be a lot of really spectacular skies there, the chances of habitability are probably very low.
The exoplanet only whips its star every 5.36 Earth days. The surface temperatures in the immediate vicinity would be at a scorching 428 Kelvin (155 ° C).
Nevertheless, astronomers are curious to take a closer look. That's because the LTT 1445Ab could have an atmosphere – and rocky planets with atmospheres circling in front of their stars are a good place to test the detection tools we use to look for gases like methane and carbon dioxide.
A planet with one atmosphere would not only dim the light of the star, but also change it based on the chemical composition of the atmosphere. In particular, scientists can analyze changes in the light spectrum of the star to compose this composition.
Our current active technology is not very well suited for this, but hopes for Hubble's successor, the James Webb Space Telescope, are high. It is due to be launched in 2021, and astronomers are eagerly searching for targets they want to investigate.
LTT 1445Ab could be a perfect candidate. Since it goes through so often, there are many observation possibilities. It's only 22.5 light-years away – relatively close, in cosmic scales. His red dwarf star is bright enough to illuminate the atmosphere from behind, but not so bright that the planet is completely in the shade.
And even if it has no atmosphere or if its atmosphere contains no biosignatures, it's rocky planets are relatively common in tight orbits around red dwarf stars. A closer look at LTT 1445Ab could tell us more about what we can expect on such planets.
The article was submitted to The Astronomical Journal and is available on arXiv.