2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Visualization of a 3D map of brown dwarfs created by scientists
Volunteers participating in the civil science project Backyard Worlds: Planet 9 (open to both scientists and amateur astronomers) have helped create the most comprehensive 3D map of brown dwarf distributions around the solar system to date. The work, which is reported on the NASA website, was presented at the 237th meeting of the American Astronomical Union.
Brown dwarfs are neither stars nor planets. Their mass is insufficient to support thermonuclear "combustion" of hydrogen, but in the bowels of such objects, reactions take place with the participation of deuterium and lithium nuclei. After exhausting the reserves of light elements, brown dwarfs cool off relatively quickly, turning into planet-like objects, thus never entering the main sequence of the Hertzsprung-Russell diagram. Their masses are between 13 and 80 Jupiter's masses, and their surface temperature usually does not exceed a thousand kelvin.
Due to low temperatures and small size, brown dwarfs have an extremely low luminosity (it is about a thousandth of the solar luminosity), which makes it difficult to find and observe them. However, they are of great interest to astronomers, because they can tell about the processes of formation of stars and exoplanets.
The authors of the paper presented at the conference used data from the CatWise catalog and the civil science project Backyard Worlds: Planet 9, which was launched in 2017. Its main goal is to search for brown dwarfs and "planets X" in the archives of the Wide-field Infrared Survey Explorer (WISE) telescope. Scientists and hobbyists alike are looking at infrared images to look for potentially interesting objects.
The researchers selected 361 L-, T-, and Y-type brown dwarfs and estimated their distance using the Spitzer telescope. They then combined the findings with previous discoveries to create a 3D map that includes 525 sub-stellar objects. It spans a radius of 65 light years; the closest neighbors to the solar system are within about 35 light years.
Some of the L, T, and Y dwarfs have masses and temperatures close to those of exoplanets. That said, getting detailed information about distant planets can be difficult, because the light of the stars around which they revolve dwarfs them. Since the brown dwarfs in this study do not orbit stars, astronomers will not need to subtract the light from the stars. This potentially makes brown dwarfs a convenient laboratory for studying the properties of exoplanets.
In the future, researchers will be able to learn more about brown dwarfs with the James Webb Space Infrared Telescope, which is slated to launch in October 2021. In addition, NASA's SPHEREx mission, which will conduct a full infrared survey of the entire sky, will also provide a better understanding of the characteristics of brown dwarfs.
Usually brown dwarfs search for thermal infrared radiation, but recently astronomers were able to discover such an object for the first time using a radio telescope. In addition, scientists recently recorded a super-powerful outbreak on an L-type brown dwarf.