AF And - An LBV/S Dor Variable In Outburst
ATel #10383; John C. Martin (University of Illinois Springfield, IL, USA), Roberta M. Humphreys (University of Minnesota, MN, USA), Kamil Hornoch (Astronomical Institute, Ondrejov, Czech Republic)
on 16 May 2017; 21:25 UT
Credential Certification: John Martin (email@example.com)
Subjects: Optical, Star, Variables
The classical Luminous Blue Variable (Humphreys & Davidson, 1994) AF And = J004333.08+411210.3 = Var 19 in M31 (Hubble & Sandage, 1953) is currently undergoing an S Doradus outburst. Brightening was first noted by Hornoch and Kucakova using the 0.65-m telescope at Ondrejov observatory at R = 15.77 +/- 0.07 (2017 May 8.088 UT) and R = 15.80 +/- 0.04 (2017 May 11.064 UT). It was confirmed with pre-dawn BVR imaging in twilight on May 14 & 15 by the 20-inch telescope at the University of Illinois Springfield Henry R. Barber Observatory in Pleasant Plains, IL, USA.
Over the last 800 days its BVRI brightness has increased more than one magnitude while getting redder. Since Sept it has increased 0.6 mag in V and reddened from (V-R) = 0.27 to 0.37. Presently, the sun-angle is < 30 deg and increasing.
Plots of photometry from UIS Barber Observatory 20-inch in link below.
Photometry and color of AF And from UIS 20-inch Telescope: