London: A global group of researchers has recognized 5 objects which have plenty close to the border separating stars and “brown dwarfs” that might assist scientists perceive the character of those mysterious objects.
Brown dwarfs are astronomical objects with plenty between these of planets and stars. The query of the place precisely the boundaries of their mass lie stays a matter of debate, particularly since their structure is similar to that of low-mass stars.
“We nonetheless have no idea precisely the place the mass limits of brown dwarfs lie, limits that enable them to be distinguished from low-mass stars that may burn hydrogen for a lot of billions of years, whereas a brown dwarf may have a brief burning stage after which a colder life,” stated Nolan Grieves, a researcher within the Division of Astronomy on the College of Geneva (UNIGE).
The group, led by scientists from the UNIGE and the Swiss Nationwide Centre of Competence in Analysis (NCCR) Planets, in collaboration with the College of Bern, characterised 5 companions that had been initially recognized with the Transiting Exoplanet Survey Satellite tv for pc (TESS) as TESS objects of curiosity (TOI) — TOI-148, TOI-587, TOI-681, TOI-746 and TOI-1213.
These are known as ‘companions’ as a result of they orbit their respective host stars. They achieve this with intervals of 5 to 27 days, have radii between 0.81 and 1.66 instances that of Jupiter and are between 77 and 98 instances extra large. This locations them on the borderline between brown dwarfs and stars. These 5 new objects subsequently include precious data, the group stated. The findings are detailed within the journal Astronomy and Astrophysics.
“Every new discovery reveals further clues in regards to the nature of brown dwarfs and provides us a greater understanding of how they type and why they’re so uncommon,” stated Monika Lendl, a researcher within the Division of Astronomy on the UNIGE and a member of the NCCR Planets.
One of many clues the scientists discovered to indicate these objects are brown dwarfs is the connection between their dimension and age.
“Brown dwarfs are alleged to shrink over time as they deplete their deuterium reserves and funky down. Right here we discovered that the 2 oldest objects, TOI 148 and 746, have a smaller radius, whereas the 2 youthful companions have bigger radii,” stated Francois Bouchy, Professor at UNIGE.
But these objects are so near the restrict that they might simply as simply be very low-mass stars, and astronomers are nonetheless uncertain whether or not they’re brown dwarfs.
“Even with these further objects, we nonetheless lack the numbers to attract definitive conclusions in regards to the variations between brown dwarfs and low-mass stars. Additional research are wanted to search out out extra,” Grieves stated.