The two red lines in this Hubble image point to a a Luminous Fast Blue Optical Transient (LFBOT) cataloged as AT2023fhn. LFBOTs shine intensely in blue light and evolve rapidly, reaching peak brightness and then fading in a matter of days. Supernovae, on the other hand, take weeks or months to dim. All other LFBOTs have been found in star-forming regions in the spiral arms of galaxies, Tbut this latest transient lies well away from the barred spiral galaxy at right and the dwarf galaxy to the upper left. It’s not clear what astronomical event would trigger such a blast far outside of a galaxy. ‘Tis a puzzlement.

Image Credit: NASA / ESA / STScI / Ashley Chrimes (ESA-ESTEC/Radboud University)