Ordinary brown dwarfs are not that rare. Volunteers from Backyard Worlds: Planet 9 have discovered more than 4,000 of them! However, the others are not known to leave the galaxy.
This new object has another unique property. Data obtained with the WM Keck Observatory in Maunakea, Hawaii, show that it contains much less iron and other metals than other stars and brown dwarfs. This unusual composition suggests that CWISE J1249 is quite old and probably belongs to one of the first generations of stars in our galaxy.
Why is this object moving at such a high speed? One theory is that CWISE J1249 originally came from a binary star system with a white dwarf that exploded as a supernova when it stripped too much material from its companion. Another possibility is that it came from a tightly connected star cluster called a globular cluster and flew away through a chance encounter with a pair of black holes.
“When a star encounters a binary black hole system, the complex dynamics of this three-body interaction can eject the star directly from the globular cluster,” says Kyle Kremer, incoming assistant professor in the Department of Astronomy and Astrophysics at UC San Diego.
Scientists will examine the elemental composition of CWISE J1249 more closely to find clues as to which of these scenarios is more likely.
This discovery was the result of a team effort on several levels – a collaboration between volunteers, professionals and students. Kabatnik thanks other citizen scientists for their help in the search, including Melina Thévenot, who “blew me away with her personal blog about searching with the Astronomical Data Query Language,” he said. Software written by citizen scientist Frank Kiwy also played an important role in this discovery, he said.
The study is led by Backyard Worlds: Planet 9 science team member Adam Burgasser, a professor at the University of California, San Diego, and includes co-authors Hunter Brooks and Austin Rothermich, astronomy students who both began their astronomy careers as citizen scientists.
Become a Citizen Scientist
Want to help discover the next extraordinary object in space? Enter Backyard Worlds: Planet 9 now – it’s open to anyone in any country in the world.
Podcast
Listen to this NASA “Curious Universe” podcast episode to hear personal stories from citizen scientists involved in NASA-related projects.
