Independent Discovery of a Slowly Brightening Object in M31
ATel #12417; K. Hornoch, H. Kucakova (Astronomical Institute, Ondrejov, Czech Republic), M. Wolf (Astronomical Institute, Charles U., Prague, Czech Republic)
on 23 Jan 2019; 22:53 UT
Credential Certification: Allen W. Shafter (ashafter@sdsu.edu)
Subjects: Nova, Transient
We report the independent discovery of a slowly brightening object in M31 on a co-added 990-s R-band CCD frame taken on 2019 Jan. 1.750 UT with the 0.65-m telescope at Ondrejov.
The object was independently discovered and first announced as possible nova by M. Zhang and X. Gao and designated as AT2019yw. The object was designated by us as TCP J00430003+4118341 and is located at R.A. = 0h43m00s.03, Decl. = +41o18'34".1 (equinox 2000.0), which is 177.0" east and 145.6" north of the center of M31 (see link to discovery image below). Since the object was brightening too slowly for typical novae in M31, we did not announce the discovery initially, suspecting it might be some other type of variable star. On the other hand, there is a known example of a slowly evolving Fe II nova M31N 2010-10b (see ATel #3039), which brightened from 20 to 19.4 mag in R-band over the course of a month. Thus, we strongly encourage spectroscopic observations to reveal nature of the object.
The following R-band magnitudes were obtained using the 0.65-m telescope at Ondrejov:
2018 Nov. 29.871 UT, [20.9; Dec. 18.669, 21.0 ± 0.5 (marginal detection); 2019 Jan. 1.750, 19.5 ± 0.3; 14.740, 19.6 ± 0.4; 19.691, 19.5 ± 0.3; 19.706, 19.6 ± 0.3; 20.924, 19.2 ± 0.3; 21.711, 19.3 ± 0.2; 22.763, 19.1 ± 0.2.
Discovery image
