MAY 27, 2022 9:05 AM PDT

Astronomers Discover Over 700 Ultracool Dwarfs

A new study in Astronomy & Astrophysics published the largest catalog of ultracool dwarfs to date. The team at the National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) used low-resolution spectral data from Large Sky Area Multi-Object Fiber Spectroscopic Survey Data Release 7 (LAMOST DR7) to compile a catalog of 734 ultracool dwarfs, the largest homogenous sample of ultracool dwarfs with detailed stellar parameters.

 

Ultracool dwarfs are a class of objects that include very low mass stars (“M-type” stars – the least massive class of stars) and candidates of brown dwarfs. Brown dwarfs are substellar objects, a class of objects that is an intermediate between a planet and a star, i.e., too massive to be a planet, yet not massive enough to be a star. Brown dwarfs cannot perform hydrogen fusion in their cores and thus, are usually nicknamed “failed stars.” These types of objects are red in color and very faint, which makes them extremely difficult to observe. They are also much cooler than most stars, having a temperature of less than 2,700 K. M type stars are important for studying the chemical reactions and physical processes that occur at the transition region of objects between stars and brown dwarfs. M-type stars have become increasingly popular in recent years as they are ideal targets for searching for terrestrial – or rocky – planets like Earth.

Brown dwarfs inhabit a mass regime between planets and stars; they are too big to be planets and yet not big enough to be stars. Credit: NASA/JPL-Caltech

The team used LAMOST, a telescope located in Xinglong Station, Hebei Province, China. LAMOST is a large-scale spectroscopic survey of the night sky visible from China, whose goal is to survey 10 million stars in the Milky Way, as well as millions of galaxies in our Universe. Using a new collection of data released in 2019, data release 7 (DR7), the team examined a sample of spectra of 10,000 M-type stars. The team then examined and compared the spectra of these stars and identified 734 ultracool dwarfs in the sample. This is the largest sample of M type ultracool dwarfs in a single work with a rich stellar parameter set derived homogenously. The objects are between 326 and 1174 light-years from Earth and approximately 300 million years old. This sample of objects is vital in studying the properties and evolution of ultracool dwarfs, key targets for looking for habitable planets. This large sample may help astronomers understand how these objects form and the internal nature of these objects, which is relatively unknown at this point in time.

 

Source: Chinese Academy of Sciences

About the Author
PhD in Astrophysics
I'm a stellar astrophysicist by training with a passion for formal and informal education and diversity and inclusion in STEM. I love to take a humanistic approach to my work and firmly believe that all of humanity is united under one sky.
You May Also Like
APR 15, 2022
Chemistry & Physics
Chaos Theory Hints at Controlling Our Weather
APR 15, 2022
Chaos Theory Hints at Controlling Our Weather
In the last few years, we witnessed countless wildfires, and a big increase in the number of tornados, droughts, and flo ...
APR 24, 2022
Space & Astronomy
Happy Anniversary, Hubble!
APR 24, 2022
Happy Anniversary, Hubble!
32 years ago today, NASA’s Hubble Space Telescope (HST) was launched aboard Space Shuttle Discovery and deployed i ...
APR 26, 2022
Space & Astronomy
NASA's Perseverance Rover Captures Solar Eclipse on Mars
APR 26, 2022
NASA's Perseverance Rover Captures Solar Eclipse on Mars
“NASA's Perseverance Rover Captures Solar Eclipse on Mars” NASA’s Perseverance (Percy) Rover has c ...
JUN 24, 2022
Space & Astronomy
Dying Stars Could Enrich the Interstellar Medium with Carbon Nanotubes
JUN 24, 2022
Dying Stars Could Enrich the Interstellar Medium with Carbon Nanotubes
In a paper recently accepted for publication in the Journal of Physical Chemistry A, researchers at the University of Ar ...
JUL 09, 2022
Chemistry & Physics
Exotic Exoplanets where the Clouds are made of Sand
JUL 09, 2022
Exotic Exoplanets where the Clouds are made of Sand
As humans we are used to seeing light and fluffy clouds that are made of water. However, beyond the scope of our planet, ...
JUL 08, 2022
Chemistry & Physics
34 Brown Dwarfs in Binary Systems Found via Citizen Science - Doubling What we Knew!
JUL 08, 2022
34 Brown Dwarfs in Binary Systems Found via Citizen Science - Doubling What we Knew!
Brown dwarfs, which are popularly known as failed stars, form a boundary between the most massive planets and the smalle ...
Loading Comments...