20,000 observations from the Calar Alto telescope, in Almería, Spain, have been made public, which have made possible the discovery of 59 planets, some of them potentially habitable.
The CARMENES project team has just published data corresponding to some 20,000 observations taken between 2016 and 2020 of a sample of 362 nearby cool stars. The project, which is financed with Spanish and German funds, uses an instrument built at the Calar Alto Observatory with the purpose of finding exoplanets (planets outside our solar system) similar to Earth (rocky and temperate), with the possibility of harbor water on its surface if they are located in the so-called “habitable zone” around their star. Among the multitude of data obtained, those that have allowed the discovery of 59 exoplanets stand out, a dozen of which are potentially habitable. The study has been published in the academic journal Astronomy & Astrophysics.
CARMENES is the name of the scientific project, but also of the instrument with which the observations are made and of the consortium that was in charge of designing and building it. More than 200 scientists and engineers from 11 Spanish and German institutions bring the project to life, in which researchers from the Institute for Space Studies of Catalonia (IEEC) and the Institute of Space Sciences (ICE), dependent on the Council, play a leading role. Superior of Scientific Investigations (CSIC) in Spain). In fact, the director of the IEEC, Ignasi Ribas, is the first author of this recently published work. He is accompanied by a hundred experts from more than 30 research centers, including the Max Planck Institute for Astronomy (MPIA) in Germany, the Institute of Astrophysics of Andalusia (IAA) in Spain, the Göttingen Institute of Astrophysics ( IAG) in Germany, the Complutense University of Madrid (UCM) in Spain, the Instituto de Astrofísica de Canarias (IAC) in Spain, the Center for Astrobiology (CAB) in Spain and the Spanish-German Astronomical Center (CAHA), among others. institutions.
The CARMENES instrument is a spectrograph that operates in the optical band and in the near infrared, that is, a device that measures both visible light and the part of the infrared closest in wavelength to visible light, from objects towards those who aim It was installed in 2015 at the Calar Alto Observatory with the aim of finding terrestrial-type exoplanets in nearby cold stars (so-called red dwarfs). The light collected from a certain star (the stellar spectrum) can reveal the presence of exoplanets, since it allows us to measure the small movements of the star produced by the gravitational attraction of the planets that orbit it.
The high-resolution spectra obtained with CARMENES are used to determine the speed of the star with a precision of one meter per second, which represents a first-rate technological challenge. This makes it possible to find small planets around low-mass stars.
“Since it came into operation, CARMENES has reanalyzed 17 known planets and has discovered and confirmed 59 new planets in the vicinity of our solar system, contributing notably to expanding the census of nearby exoplanets,” explains Ribas. In fact, this instrument has multiplied the number of exoplanets that we know of around nearby cold stars, doubling those detected with the previously exposed method. It is to be hoped that, with the publication of this first large set of data, the research community will begin to analyze them and can further increase their scientific production. It should be noted that with CARMENES practically half of all nearby small stars have been observed (a part of them can only be observed from the southern hemisphere). In addition, the spectra obtained also provide very valuable information about the atmospheres of the stars and their planets, among other characteristics.
Artist’s impression of an Earth-sized planet in the habitable zone of a nearby red dwarf. (Image: Render Area / CARMENES / JA Caballero)
The study published in Astronomy & Astrophysics is precisely number 100 of the CARMENES consortium, which shows the success that the project has achieved by providing information on Earth-like exoplanets and their respective stars. In this study, the data corresponding to the information obtained with visible light have been published. Experts are still improving the processing of the infrared data, so when it is published, astronomers will have a second large set of observations to work with.
The CARMENES project has its continuity in CARMENES Legacy-Plus, which started in 2021 and continues to take more observations on the same stars. “In order to determine the existence of planets around a star, we observe it a minimum of 50 times,” explains Juan Carlos Morales, IEEC researcher at ICE. And he adds: “Although the first round of data has already been published for the scientific community to access, these series of observations are not yet complete.” The observations made in this extension of the project will continue at least until the end of 2023. (Source: IEEC / ICE / CSIC / CAB / INTA / IAA / IAC / UCM)