INT/WFC improved position and follow-up photometry of the red LPV AT2018hcd (= XMNGS1) in M31

ATel #12309; M. Fernandez-Torreiro (ULL), A. Alvarez-Saavedra (ULL), R. M. Doblas-Cabezas (ULL), D. SanJulian-Jacques (ULL), A. Alvarez-Hernandez (ULL), P. Carro-Portos (ULL), E. A. Diaz-Suarez (ULL), E. M. Garcia-Zamora (ULL), A. Hernandez-Garcia (ULL & IAC), M. Mallorquin (ULL), J. E. Mendez-Delgado (ULL & IAC), D. Moral-Pombo (ULL), M. A. Nuñez-Cagigal (ULL & IAC), G. Panizo-Espinar (ULL), J. Sanchez-Sierras (ULL), H. Villegas-Beberide (ULL), L. Monteagudo (ING) and I. Perez-Fournon (ULL & IAC)
on 19 Dec 2018; 14:46 UT
Credential Certification: Ismael Perez-Fournon (ipf@iac.es)

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We report the improved position and photometry of a red LPV in M31 from CCD images taken with the Wide Field Camera of the Isaac Newton Telescope at Roque de los Muchachos Observatory. The discovery of this transient was reported to TNS by Xingming Observatory Sky Survey (XOSS) and it was confirmed as a red LPV by S. C. Williams, M. J. Darnley, M. W. Healy (ATel #12138).

We report here the INT photometry in the Sloan g, r, and i filters, calibrated using Pan-STARRS1, and the improved position based on the INT images, calibrated using the Gaia DR2 catalog. RA(J2000) = 00:43:32.476, Dec. (J2000) = +41:07:12.60. This position is offset by 0.52 arcsec from the position given by Xingming Observatory Sky Survey (XOSS).

The INT magnitudes of the LPV are:

g = (21.06+/- 0.10), 2018-10-13.012 UT, exposure time = 120 seconds

r = (19.98 +/- 0.07), 2018-10-13.013 UT, exposure time = 120 seconds

i = (18.97 +/- 0.05), 2018-10-13.011 UT, exposure time = 120 seconds

g = (21.88 +/- 0.10), 2018-10-14.127 UT, exposure time = 54 minutes

r = (20.39 +/- 0.07), 2018-10-14.076 UT, exposure time = 54 minutes

i = (19.15 +/- 0.05), 2018-10-14.027 UT, exposure time = 54 minutes

This red LPV star is also detected in the i, z, and Y bands of Pan-STARRS1:

i = 21.0631 +/- 0.0606

z =19.3196 +/- 0.1954

Y = 19.418 +/- 0.124

PS1 cutouts.

Based on observations made with INT telescope operated on the island of La Palma by the Isaac Newton Group in the Observatorio del Roque de los Muchachos.

We thank David Bishop for his wonderful compilation of extragalactic novae and supernovae.

INT WFC and Pan-STARRS1 i-band images