Utilizing the Keck II telescope, astronomers have detected an object which may be a brown dwarf or a low-mass star, exhibiting a really excessive radial velocity. The article, designated CWISE J124909.08+362116.0 is positioned some 400 mild years away. The discovering was reported July 11 on the pre-print server arXiv.
Brown dwarfs (BDs) are intermediate objects between planets and stars, occupying the mass vary between 13 and 80 Jupiter plenty (0.012 and 0.076 solar plenty). They type like stars however aren’t sufficiently huge to maintain hydrogen fusion of their cores.
Now, a staff of astronomers led by Adam Burgasser of the College of California San Diego studies the detection of a brand new object on the brown dwarf/star mass boundary.
Utilizing the Close to-Infrared Echellette Spectrometer (NIRES) on the Keck II telescope, they investigated CWISE J124909.08+362116.0 (or CWISE J1249+3621 for brief)—a excessive correct movement faint crimson supply first recognized by citizen scientists. Because of this, it turned out that the supply is a uncommon sort of hypervelocity subdwarf.
“We report the invention of a excessive velocity, very low-mass star or brown dwarf whose kinematics counsel it’s unbound to the Milky Way. (…) The quickest ‘hypervelocity’ stars are unbound to the Milky Way’s gravitational potential and should even have extragalactic origins,” the researchers defined.
In line with the examine, CWISE J1249+3621 has a big radial velocity—at a degree of -103 km/s. This provides the galactic relaxation body velocity of 456 km/s, which corresponds to 1,530 mild years per a million years. On condition that this result’s just under the galactic escape velocity on the solar radius, which is at the moment estimated to be 521–580 km/s, the astronomers conclude that this object has a big likelihood of being unbound to the Milky Way.
The observations discovered that CWISE J1249+3621 has a mass of some 0.082 solar plenty and its effective temperature is estimated to be 1,715–2,320 Okay. The metallicity of CWISE J1249+3621 was measured to be inside a variety of -1.4 and -0.5.
Based mostly on the collected knowledge, the authors of the paper assume that CWISE J1249+3621 is probably going a hypervelocity metal-poor, early-type L subdwarf star somewhat than a brown dwarf. They underline that it could due to this fact be the primary identified low-mass hypervelocity star and the closest such object to Earth.
In attempting to find out the origin of CWISE J1249+3621, the researchers have in mind a number of totally different hypotheses, together with ejection from the galactic center greater than three billion years in the past, or a survival because the companion to an accreting white dwarf that exploded.
Additional investigation into bodily and atmospheric properties of this object is required as a way to infer its true origin.
Extra data:
Adam J. Burgasser et al, Discovery of a Hypervelocity L Subdwarf on the Star/Brown Dwarf Mass Restrict, arXiv (2024). DOI: 10.48550/arxiv.2407.08578
Journal data:
arXiv
© 2024 Science X Community
Quotation:
Observations detect a close-by hypervelocity stellar/substellar object (2024, July 18)
retrieved 19 July 2024
from https://phys.org/information/2024-07-nearby-hypervelocity-stellarsubstellar.html
This doc is topic to copyright. Other than any honest dealing for the aim of personal examine or analysis, no
half could also be reproduced with out the written permission. The content material is supplied for data functions solely.
