-- Sebastián Otero VSX Team American Association of Variable Star Observers 185 Alewife Brook Pkwy Ste 410 Cambridge, MA 02138-1104 www.aavso.org ------------------------ The mission of the AAVSO is to enable anyone, anywhere, to participate in scientific discovery through variable star astronomy.
AM Cyg is a 370 d. mira-type variable that ranges between visual magnitudes 10.5 and 15.3.On the morning of December 1 was rising to V= 14.0 (latest observation from ZTF), but the AAVSO has received a report from Charlie Worrick (Chatham, MA) indicating that the star may have brightened very quikcly during that day, reaching 8th magnitude over 21 hours and becoming bluer.
We need to rule out instrumental problems, but a quick inspection of the images did not reveal anything unusual with them, and AM Cyg seems to have indeed brightened.The last AAVSO observation was made November 16, and the ASAS-SN database can’t be accessed right now, so we need confirmation from observers all around the world.
We can’t rule out a line-of-sight coincidence of a potential nova candidate (in that case the amplitude would be >12 mag.) in the background, but that seems highly unlikely.
Such a brightening in a mira-type variable wouldn’t be unprecedented. V0407 Cyg was a 768 d. mira and had a nova outburst in 2010. It turned out to be a symbiotic system. This one might be similar, but we need confirmation!
Please observe the field as soon as possible and also report your observations to the AAVSO if you can.
AM Cyg is at 20 49 00.85 +31 50 55.8 (J2000.0)
https://www.aavso.org/vsx/index.php?view=detail.top&oid=10986
Best wishes,
Sebastian
-- Sebastián Otero VSX Team American Association of Variable Star Observers 185 Alewife Brook Pkwy Ste 410 Cambridge, MA 02138-1104 www.aavso.org ------------------------ The mission of the AAVSO is to enable anyone, anywhere, to participate in scientific discovery through variable star astronomy.