Monday, August 05, 2024

A supernova spotlight

A close-in view of a barred spiral galaxy. The bright, glowing bar crosses the centre of the galaxy, with blurred spiral arms curving away from its ends and continuing out of view. It’s surrounded by bright points of light that indicate stars and galaxies. The galaxy also hosts a bright supernova in its central bar.Credit: ESA/Hubble & NASA, R. J. Foley

This Hubble Picture of the Week features the galaxy LEDA 857074, located in the constellation Eridanus. LEDA 857074 is a barred spiral galaxy, with partially broken spiral arms. It also has a particularly bright spot right in its bar: this is a supernova snapped by Hubble, named SN 2022ADQZ, and quite relevant to this Picture of the Week.

The NASA/ESA Hubble Space Telescope has observed a vast range of celestial objects, from galaxies, to nebulae, to star clusters, to planets in the Solar System and beyond. Observing programmes usually seek to gather data so that astronomers can answer a specific question. Naturally, this means most scheduled observations target an object that astronomers have already researched. Some are famous, like the Crab Nebula or the globular cluster Omega Centauri; others might not be so well known to the public, but still be featured in hundreds of scientific papers, such as the Spider Galaxy or NGC 4753. Not so with this galaxy: LEDA 857074 is named in fewer than five papers, one of which is the Lyon-Meudon Extragalactic Database itself. Virtually no data have been recorded about it, other than its position: since its discovery, it simply hasn’t been studied. So how did it attract the gaze of the legendary Hubble?

The supernova is the answer — SN 2022ADQZ was detected by an automated survey in late 2022, and led to Hubble being pointed at its host galaxy, LEDA 857074, in early 2023. Astronomers have catalogued millions of galaxies, so while today tens of thousands of supernovae are detected annually, the chance that one is spotted in any particular galaxy is slim. We also do not know how actively LEDA 857074 is forming stars, and therefore how often it might host a supernova. This galaxy is therefore an unlikely and lucky target of Hubble, thanks to this supernova shining a spotlight on it! It now joins the ranks of many more famous celestial objects, with its own Hubble image.