Hubble's Space Telescope image of a Luminous Fast Blue Optical Transient (LFBOT)

Hubble's Space Telescope image of a Luminous Fast Blue Optical Transient (LFBOT)

A Hubble Space Telescope image of a Luminous Fast Blue Optical Transient (LFBOT) designated AT2023fhn, indicated by pointers. It shines intensely in blue light and evolves rapidly, reaching peak brightness and fading again in a matter of days, unlike supernovae which take weeks or months to dim. Only a handful of previous LFBOTs have been discovered since 2018. The surprise is that this latest transient, seen in 2023, lies at a large offset from both the barred spiral galaxy at right and the dwarf galaxy to the upper left. Only Hubble could pinpoint its location. And, the results are leaving astronomers even more confounded because all previous LFBOTs have been found in star-forming regions in the spiral arms of galaxies. It’s not clear what astronomical event would trigger such a blast far outside of a galaxy.

[Image Description: This Hubble photograph shows three galaxies against the velvet-black backdrop of space. The largest is the white and blue spiral-shaped galaxy at the image centre. Two smaller galaxies are whitish patches toward the left. A curious white spot near the top of the image is marked out with two perpendicular orange lines. It is the glow from some unknown object that exploded, but isn’t associated with any of the galaxies.]

Credit:
NASA, ESA, STScI, A. Chrimes (Radboud University)