Artists view revealing the red star and its two worlds, together with a few of the telescopes used for the discovery. The information that led to the discovery is depicted on the solar panels of the TESS satellite. Credit: University of Birmingham/ Amanda J. Smith
Astronomers Discover Two New Temperate Rocky Worlds
A global research study team has simply revealed the discovery of two “super-Earth” worlds orbiting LP 890-9, a little, cool star situated about 100 light-years from Earth. The star, also called TOI-4306 or SPECULOOS-2, is the second-coolest star found to host planets, after the well-known TRAPPIST-1. This unusual discovery is the topic of an upcoming publication in the journal Astronomy & & Astrophysics.
LP 890-9b, the systems inner world, is about 30% larger than Earth and finishes an orbit around the star in just 2.7 days. SPECULOOS astronomers then utilized their telescopes to search for additional transiting planets in the system that could have been missed by TESS.
” TESS look for exoplanets using the transit method, by monitoring the brightness of thousands of stars all at once, trying to find minor dimmings that may be triggered by worlds passing in front of their stars,” explains Laetitia Delrez, a postdoctoral scientist at the University of Liège, and the lead author of the new research study article.
” However, a follow-up with ground-based telescopes is frequently necessary to verify the planetary nature of the identified prospects and to improve the measurements of their sizes and orbital properties.”
This follow-up is particularly essential when it comes to really cold stars, such as LP 890-9. This is because they discharge the majority of their light in the near-infrared, a wavelength for which TESS has a rather limited sensitivity.
On the other hand, the telescopes of the SPECULOOS task, which are set up at ESOs Paranal Observatory in Chile and on the island of Tenerife, are optimized to observe this kind of star with high accuracy. This is since they have cameras that are very delicate to near-infrared wavelengths.
” The goal of SPECULOOS is to look for potentially habitable terrestrial worlds transiting a few of the tiniest and coolest stars in the solar area, such as the TRAPPIST-1 planetary system, which we discovered in 2016,” recalls Michaël Gillon, from the University of Liège, and the primary investigator of the SPECULOOS project. “This technique is inspired by the reality that such worlds are particularly well matched to detailed studies of their atmospheres and to the search for possible chemical traces of life with big observatories, such as the James Webb Space Telescope (JWST).”.
The observations made by SPECULOOS of LP 890-9 showed quite worthwhile as they not only validated the first planet, but they were critical for the detection of a 2nd, formerly unidentified exoplanet. This second world, LP 890-9c (renamed SPECULOOS-2c by the SPECULOOS researchers), is comparable in size to the very first (about 40% larger than Earth) however has a longer orbital period of about 8.5 days. This orbital duration, later validated with the MuSCAT3 instrument in Hawaii, places the planet in the so-called “habitable zone” around its star.
” The habitable zone is an idea under which a planet with similar geological and climatic conditions as Earth, would have a surface area temperature level permitting water to remain liquid for billions of years” discusses Amaury Triaud. He is a professor of Exoplanetology at the University of Birmingham and the leader of the SPECULOOS working group that set up the observations resulting in the discovery of the second world. “This provides us a license to observe more and find out whether the planet has an environment, and if so, to study its content and assess its habitability.”.
The next step will be to study the atmosphere of this planet, for example with the JWST. LP 890-9c seems the second-most favorable target for the JWST among the possibly habitable terrestrial planets known so far, surpassed only by the TRAPPIST-1 planets (for which Professor Triaud was also a co-discoverer).
” It is very important to find as many temperate terrestrial worlds as possible to study the diversity of exoplanet climates, and ultimately to be in a position to measure how often biology has actually emerged in the Cosmos,” added Professor Triaud.
Recommendation: “Two temperate super-Earths transiting a close-by late-type M dwarf” 7 August 2022, Astronomy and Astrophysics.DOI: 10.1051/ 0004-6361/2022 44041.
Birminghams funding for this research study originated from the European Research Council (ERC) grant BEBOP, along with two grants from the Science and Technology Facilities Council (STFC) and a financial investment by the University of Birmingham to purchase a SPECULOOS telescope.
About SPECULOOS.
SPECULOOS is a project led by the University of Liège (job leader: Michaël Gillon) and performed in partnership with the University of Cambridge, the University of Birmingham, the Massachusetts Institute of Technology, the University of Bern, the Canary Islands Institute of Astrophysics, and the European Southern Observatory (ESO). It is based on a network of robotic telescopes whose primary cores are the observatories SPECULOOS-South at ESOs Paranal Observatory in Chile (4 telescopes) and SPECULOOS-North in Tenerife (currently 1 telescope), matched by the SAINT-EX (1 telescope in Mexico) and TRAPPIST (2 telescopes, 1 in Chile and 1 in Morocco) telescopes.
Artists view showing the red star and its two worlds, together with some of the telescopes utilized for the discovery. A worldwide research group has actually just revealed the discovery of two “super-Earth” planets orbiting LP 890-9, a little, cool star located about 100 light-years from Earth. The star, also called TOI-4306 or SPECULOOS-2, is the second-coolest star discovered to host worlds, after the famous TRAPPIST-1. LP 890-9b, the systems inner planet, is about 30% larger than Earth and completes an orbit around the star in just 2.7 days. SPECULOOS astronomers then utilized their telescopes to browse for extra transiting worlds in the system that could have been missed out on by TESS.
