The All Sky Automated Survey for SuperNovae (ASAS-SN)
is a survey using 24 telescopes around
the world.
(It began with four telescopes at Haleakala, Hawaii,
and four at Cerro Tololo, Chile.)
It is an improved version of All Sky Automated Survey (ASAS) with
better sensitivity for discovering more transients
including distant supernovae,
able to detect new objects with magnitudes 8 to 18.
Discovered objects are labeled ASASSN-xxxx,
the latter part being two digits and two letters.