First time detection of nuclear explosion from Andromeda Galaxy, using Astrosat. I'm pretty sure that the Andromeda Galaxy is not the closest Galaxy to the Milky Way, the closest or closer are the Magellanic Clouds, the Triangulam Galaxy, Ursa Major et al. I suppose if these are seen as satellite or local group galaxies, then the wording could be accurate. Otherwise, it would make the achievement even more impressive! Astrosat is still working 9 years after its launch, its expected duration was 5 years.