In a remarkable finding, scientists have identified an object traveling at an astonishing speed of 1 million miles per hour (or 456 kilometers per second), potentially the fastest-known object in our solar system. Discovered in 2024 by citizen scientists engaged in NASA's Backyard Worlds: Planet 9 project, the object was first spotted using NASA's Wide-field Infrared Survey Explorer (WISE) telescope. This high-velocity object, named CWISE J124909.08+362116.0, is projected to escape the gravitational pull of the Milky Way, embarking on a journey into intergalactic space.
This discovery arose from the NEOWISE mission, which had concluded on August 8, 2024. Martin Kabatnik, Thomas Bickle, and Caselden were among the first individuals to observe the faint, rapidly-moving object racing through the galaxy. Although the exact nature of CWISE J1249 remains uncertain, it is speculated to be either a star or a brown dwarf—a kind of object that falls between gas giant planets and stars in terms of mass and characteristics. Unlike over 4,000 previously discovered brown dwarfs, which are expected to remain within the Milky Way, CWISE J1249 is on a trajectory to escape the galaxy.
An intriguing aspect of CWISE J1249 is its chemical makeup, indicating it may belong to some of the earliest formations in the Milky Way. Recent observations made with the W. M. Keck Observatory in Maunakea, Hawaii, revealed that CWISE J1249 has significantly lower iron and metal content than typical stars and brown dwarfs. This suggests that it could originate from one of the original generations of stars in our galaxy.
Several theories have emerged regarding its extraordinary speed and escape path. One hypothesis proposes that CWISE J1249 was originally part of a binary system alongside a white dwarf. This relationship may have led to the extraction of substantial material, resulting in a supernova explosion. Another theory suggests that CWISE J1249 originated from a tightly-knit star cluster known as a globular cluster, where interactions with pair of black holes may have expelled it from its original group.
Furthermore, astronomers speculate that CWISE J1249 could have existed hidden from detection until now, or it might have originated from a different galaxy, speeding away from our star system. Researchers are currently focusing on analyzing the elements present in CWISE J1249 to better understand its origins and the plausible scenarios leading to its record-breaking velocity. This discovery holds the potential to enhance our comprehension of objects within our universe and their behavior.