Tuesday , June 15 2021

Astronomers are discovering a new above-ground planet orbiting a red dwarf star

Artistic impression of a huge Earth in orbit around the red dwarf star GJ-740. Credit: Gabriel Perez Diaz, SMM (IAC)

In recent years, a large study of red dwarf stars has been conducted to find exoplanets in orbit. These stars have an actual surface temperature of 2400 to 3700 K (more than 2,000 degrees colder than the Sun) and a mass of 0.08 to 0.45 solar masses. In this context, a team of researchers led by Borja Toledo Padron, a doctoral student at North Ochoa la Caixa from the Canary Institute of Astrophysics (IAC), which specializes in finding planets around this type of star, made this discovery. The Earth revolves around GJ 740, a red dwarf star 36 light-years from Earth.

The planet revolves around its star for 2.4 days and is about 3 times the mass of Earth. Because the star is so close to the Sun, and because the planet is so close to the star, this new giant Earth could be the target of future research with very large diameter telescopes at the end of this decade. The results of the study were recently published in a journal Astronomy and astrophysics.

“This is the planet with the second shortest period of orbit around this type of star. The mass and time interval belong to a rocky planet with a radius of about 1.4 Earth radii and can be confirmed by further observations using he is a goat Borja Toledo Padron explains, the first author writes. The data also indicate a second planet with an orbital period of 9 years and a mass comparable to Saturn (About 100 Earth masses), although the radial velocity signal may be related to the star’s magnetic cycle (similar to the solar cycle), so more data is needed to confirm that the signal actually belongs to the planet.

Kepler’s mission, recognized as one of the most successful missions in discovering exoplanets by transit (that is, looking for small differences in the brightness of a star orbiting ourselves) through transit, found a total of 156 new planets around cold stars. According to him, this type of star is estimated to contain an average of 2.5 planets with orbit periods of less than 200 days. The search for new exoplanets around cool stars is determined by the smaller difference between the mass of the planet and the mass of stars compared to stars of warm spectral classes (which facilitates the detection of planetary signals) and the large number of stars of this type in our galaxy, “said Borja Toledo Padron.

Cold stars are also an ideal target for searching for planets using the radial velocity method. This method is based on determining small differences in the speed of the star due to the gravity of the planet in orbit using spectral observations. Because the first radial velocity signal was detected Exoplanet So far, 116 outside the solar planet have been detected around the cold star using this radial velocity method. Junay E. Gonzalez Hernandez, IAC researcher: “The main difficulty of this method is the intense magnetic activity of this type of star, which can generate spectral signals very similar to the signals produced by an exoplanet.” Author of this article.

Reference: B. “Giant Earth near the orbit around the star M1V GJ 740: Cooperation of Hyde and Carmen” Toledo Padrons, prof. , M. Pergers, G. Scandariato, M. Damasso, A. Sosetti, J. Maldonado, S. Desidera, I. Ribs, G. Michela, L. Affers, E. Gonzalez-Alvarez, G. Leto, I. Pagano , R. Zanmar Sanchez, P. Jacobbe, E. Herrero, J. K. Morales, P. J. Amado, J. A. Caballero, A. Quirenbach, A. Rainers and M. Zechmeister, April 7, 2021, Astronomy and astrophysics.
DOI: 10.1051 / 0004-6361 / 202040099

The study is part of the HADES project (Exoplanar survey of HArps-n red dwarfBecause the IAC works with Institute of Space Sciences (IEEC-CSIC) in Catalonia and the Italian GAPS program (Global architecture of planetary systems), The purpose of which is to identify and characterize exoplanets around the cold stars for which they are used Armor-N, to the Telescopio Nazionale Galileo (TNG) at the Roque de los Muchachos Observatory (Garafia, La Palma). This finding was made possible by a six-year HARPS-N observation campaign, supplemented by CARMENES spectrophotometer measurements at the 3.5-meter telescope in Calar Alto, Almeria, and the HARPS Observatory, a 3.6-meter telescope in La Silla, Chile. ) and optical support for ASAP and EXORAP surveys. IAC researchers Alejandro Suarez Mascareno and Rafael Rebolo are also involved.

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