The planetary transit method is one of the main indirect methods of detecting an exoplanet. It revealed the existence of the exoplanet LTT 1445Ac only 22 light years from the Sun but doubts remained about its radius. The Hubble Telescope has just confirmed that it is about the same size as Earth, making it a potential target for studying the composition of the atmosphere.
Whether exoplanets, the first galaxies or the planets of the Solar System, the James-Webb Space Telescope has pushed the Hubble telescope into the shadow. And yet it is still active and used AstronomyAstronomy To make interesting discoveries, as evidenced by a recent publication that can be read freely arXiv,
It belongs to an exoplanet that was discovered by the transit method only 22 light years away. SoleilSoleilIn constellationconstellation of Eridanus, inSouthern hemisphereSouthern hemisphere, named after a river in Greek mythology. It was first listed PtolemyPtolemyUntil then William HerschelWilliam Herschel who cataloged it in 1783.
The exoplanet is called LTT 1445Ac and was discovered in 2022 Transiting Exoplanet Survey Satellite ,TessTess) From NASANASA, The problem was, at that time we did not know well whether the transition occurred in a simple way or only at the boundary of the disk.starstar, So we had a significant uncertainty on its radius. We can make a fairly accurate estimate of collectivelycollectively there radial velocity methodradial velocity method As in all cases planetary transitplanetary transit But without a well-defined radius, there is also no well-established density and so it remains a mystery whether we have detected a rocky planet or not.
Methods for detecting exoplanets have diversified significantly since the 1990s. They can be classified into two main categories, direct methods and indirect methods. The three main methods are the direct imaging method, the indirect transit method, and the indirect radial velocity method. Discover exoplanets through our nine-episode web series. © A playlist proposed by CEA and Paris-Saclay University as part of a European research project H2020 Exoplanet-A
diameter 1.07 times that of earth
Fortunately, the Hubble telescope could be called to the rescue and so it was deployed to study the planetary transit of LTT 1445ac around LTT 1445a, which is part of the triple system.dwarf starsdwarf stars Red. For the record, two other exoplanets have been detected around LTT 1445A and LTT 1445B and C, located about 3 billion kilometers away from LTT 1445A.
Hubble’s precise observations show that the diameter of LTT 1445Ac is actually 1.07 times the diameter of Earth because the observed transit is completely classic, it is not grazing. This makes LTT 1445Ac the closest Earth-sized exoplanet discovered by transit.
However, it is not a exoearthexoearthbecause she’s shutting him down To revolve aroundTo revolve around So close to its M dwarf that its average surface temperature is at least 260 degrees Celsius and perhaps even higher if it AtmosphereAtmosphere Which makes it a Venusian hell.
Astrophysicist Emily Pas from Center D’astrophysicsastrophysics – Harvard and the Smithsonian in Cambridge (Massachusetts) announced about the discovery in which he participated: ” Transiting planets are exciting because we can image their atmospheres spectroscopically, not only with Hubble but also with. Telescope Spatial James-WebbTelescope Spatial James-Webb, Our measurements are important because they tell us that this is probably a telluric planettelluric planet very close. We look forward to additional observations that will allow us to better understand the diversity of planets around other stars. ,