A team of scientists led by the University of Bern, in Switzerland, announced the discovery of a planet with an unusually eccentric orbit with respect to the star in its system, helped by the work of the Mexican observatory SAINT-EX.
The planet, baptized with the name “TOI 2257 b”, is the most eccentric that has been discovered around a “cold” star , in this case a brown dwarf: the great variation of this orbit means that the temperature of the star can oscillate between 80 degrees below zero and 100 above zero, according to their discoverers.
The planet has a radius 2.2 times that of Earth, and revolves around a star much cooler than the Sun.
The discovery of TOI-2257b is reported in an article in the journal Astronomy & Astrophysics.
Found with the “transit method”
TOI 2257 b was discovered with the so-called “transit method”, very common for finding this type of stars when they are very far from the Solar System .
Using this method, an exoplanet can be detected when it is placed in the field of view between the Earth and its star, by observing the small shadows it forms in that transit.
Favorable conditions for life
The discovered exoplanet completes its orbit around the associated star in 35 days, placing itself at a distance “in which the existence of liquid water could be plausible, and therefore the conditions would be favorable for the life”, highlighted a statement from the University of Bern.
However, the considerable size of the planet suggests that it is a mostly gaseous star, with a high atmospheric pressure that is not appropriate for the existence of living beings, neither is the strong thermal oscillation caused by its eccentric orbit.
The strange orbit discovered, the discoverers of the exoplanet pointed out, could be explained by the presence in the studied system of a planet of great size, not yet confirmed, that could affect the gravitation of the TOI 2257 b.
Participation of Mexico
Researchers from the Institute of Astronomy (IA) of the National Autonomous University of Mexico participated in an international collaboration that detected the exoplanet with the SAINT-EX robotic telescope , which operates from the National Astronomical Observatory of San Pedro Mártir, in Baja California, northern Mexico.
This is the third planet detected with this equipment that works from one of the most favorable areas of the world for astronomical observation.
The The SAINT-EX telescope detected the light curves of the celestial object, that is, the light that is received from the star and how its brightness changes as a function of time. As if it were an eclipse, the exoplanet passing through its star darkens it and makes it less bright, leaving only light curves, which the equipment captures and the astronomers interpret.