The first test image from the telescope in the Vera C. Rubin Observatory has revealed a previously unnoticed trail of light that could give insight into both the history and abnormalities of the M61 galaxy. The image, captured by the colossal camera—in fact, the largest digital camera ever—of the observatory perched upon a mountain in Chile has suggested to scientists that the galaxy had, at some point, torn off from a smaller one.
Originally spotted in 1779 in the Virgo Cluster of galaxies, the M61 galaxy became well-known for hosting a large number of supernovae and producing stars at a surprisingly high rate— becoming known as a starburst galaxy for its high stellar activity. Since its discovery, the galaxy has been unraveled and documented through the use of both the James Webb Space Telescope and the Hubble Space Telescope, though this tail has not been identified until now. While some amateur astronomers had reportedly caught glimpses of the stream prior to this recent discovery, it was not professionally confirmed until the Rubin image was taken and analyzed by filtering out excess light to reveal a trail of stars (referred to as a stellar stream) 55 kiloparsecs or 180,000 light-years long. Being one of the longest of these streams discovered, the team responsible for taking and analyzing the photo proposed it as indicative of a dwarf galaxy that had been shredded apart by M61’s gravity— potentially boosting star formation and explaining the mysteries of the galaxy.
Findings have been reported in the Research Notes of the American Astronomical Society— a non-peer-reviewed index and secure online record. While the first image captured from the Vera C. Rubin observatory captured ten million galaxies, over the next decade, it will capture light from 20 billion galaxies (more than any other observatory so far) due to its telescope being designed to survey the sky in a previously unprecedented detail and reveal new objects and phenomena such as this.
Aaron Romanowsky, an astronomer at San Jose State University in California and an author of the study, comments on how “the expectation is that every single galaxy should be surrounded by these streams. It’s a fundamental part of how the galaxies are made […] We just need to look fainter, and that’s the hope with Rubin.”
