to a helium flash in a shell that had previously been inactive since the star left the asymptotic giant branch. This is known as a late thermal pulse or very late thermal pulse, depending on the exact timing. Models approximate the behaviour of FG Sagittae although there are still detailed discrepancies. See also Sakurai's Object, also known as V4334 Sgr, another presumed late thermal pulsing object. V605 Aquilae. References External links AAVSO Variable Star of the Month. FG Sagittae: June 2008 AAVSO Variable Star of the Month. FG Sagittae: November 1998 Variable stars Sagitta (constellation) Sagittae, FG Supergiants 099527 J20115606+2020044 Emission-line stars