(ORDO NEWS) — How complete is our information about objects close to the Sun? Astronomers and a group of data volunteers involved in the civilian science project Backyard Worlds: Planet 9 have discovered about 100 new cold worlds around the Sun – objects more massive than planets, but lighter than stars. Such objects are also known as brown dwarfs.
With the help of the Keka Observatory on Munakey in Hawaii, the research team discovered that several of these newly discovered worlds are among the coldest known, with some approaching Earth’s temperature — cold enough to hide water clouds.
The study will be published in the August 20, 2020 issue of the Astrophysical Journal and is available as a preprint at arXiv.org.
Finding and describing astronomical objects closer to the Sun is fundamental to our understanding of the place in the universe and its history. Nevertheless, astronomers are still finding new “inhabitants” of the solar quarter. Backyard Worlds’ new discovery is filling a previously empty gap in the range of low-temperature brown dwarfs, revealing a long-awaited missing link in their population.
UC San Diego physics professor Adam Burgasser and Cool Star researchers used Keck’s sensitive near-infrared Echellette Spectrometer (NIRES) to identify several of the faintest and coolest recently discovered brown dwarfs.
Follow-up observations using NASA’s Spitzer Space Telescope, Mon Megantic Observatory, and Las Campanas Observatory have also contributed to the temperature estimates of brown dwarfs.
Brown dwarfs are found somewhere between the most massive planets and the smallest stars. Given that they do not have the mass necessary to sustain nuclear reactions in their core, brown dwarfs are sometimes referred to as “failed stars.” Their low mass, low temperature and absence of internal nuclear reactions make them very weak and therefore extremely difficult to detect. Because of this, when searching for the coolest brown dwarfs, astronomers can only hope to find such objects relatively close to the Sun.
To help find our Sun’s coldest and closest neighbors, Backyard Worlds astronomers turned to a worldwide network of more than 100,000 civilian scientists. These volunteers are diligently examining the trillions of pixels in the telescope images to determine the subtle movements of nearby brown dwarfs and planets. Despite advances in machine learning and supercomputers, the human eye cannot yet be replaced when it comes to detecting faint moving objects.
Backyard Worlds volunteers have already discovered more than 1,500 stars and brown dwarfs around the Sun. This new discovery reveals about 100 of the coldest in this sample. NASA WISE datasets, as well as archival observations from the telescopes of the Cerro Tololo Inter-American Observatory and Kitt Peak National Observatory, also played a key role in these brown dwarf discoveries.
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