The Sun and our solar system, though seemingly stationary, move through the Milky Way at about 136 miles per second (220 kilometers per second). Recently, the discovery of a red star moving much faster has captivated scientists.
Possible explanation for the extraordinary velocity of the sub-dwarf L star named CWISE J124909+362116.0: it was part of a binary pair with a white dwarf that exploded as a supernova.
Credit: Adam Makarenko / W.M. Keck Observatory
Thanks to the citizen science project Backyard Worlds: Planet 9 and a team of astronomers, a rare star named CWISE J124909+362116.0 has been discovered moving at high speed through the Milky Way. This star might even leave our galaxy. The research was led by Professor Adam Burgasser of the University of California, San Diego.
The star was noticed by volunteers analyzing data from NASA's WISE mission. These pattern-recognition experts identified its motion, with an estimated speed of about 373 miles per second (600 kilometers per second), sufficient to escape the gravity of the Milky Way.
To learn more about this object, Adam Burgasser used the W.M. Keck Observatory in Hawaii to analyze its infrared spectrum. The data revealed it to be a sub-dwarf L, a class of very old and low-mass stars. Atmospheric models were created by Roman Gerasimov and Efrain Alvarado III, allowing for a precise match with the observed spectrum.
Two scenarios are considered to explain this trajectory. The first suggests that the star was the companion of a white dwarf, which propelled it at high speed when it exploded as a supernova. The second scenario proposes that the star was ejected from a globular cluster containing binary black holes.
To verify these hypotheses, the researchers plan to examine the elemental composition of the star. The heavy elements produced by a supernova or the chemical signatures of globular clusters could reveal its origin.