NIR photometry of M31LRN 2015
ATel #8220; Stefan Geier (GTC/IAC/ULL), Peter Pessev (GTC/IAC/ULL)
on 28 Oct 2015; 08:31 UT
Credential Certification: Peter Pessev (peter.pessev@gtc.iac.es)
Subjects: Infra-Red, Nova, Transient
A new epoch JHKs NIR photometry of the stellar merger candidate MASTER OT J004207.99+405501.1 / M31N 2015-01a / M31LRN 2015 (Kurtenkov et al. 2015, Williams et al. 2015, ATel #6911, ATel #7150) has been obtained. In the morning hours of September 28th we carried out observations with the 2.5m Nordic Optical Telescope (NOT) at the Observatorio Roque de Los Muchachos (ORM), La Palma, using the NOTCam instrument. We obtained 700sec, 720sec, and 700sec of total exposure time in the J-, H-, and Ks-band, respectively. As outlined in ATel #7624, five nearby 2MASS stars with accurate magnitudes (AAA quality flags) were used for the photometric calibration. The photometry data points are listed below:
UT Band Mag Merr AM Seeing
2015-09-28.08 J 18.89 0.12 1.03 1.04
2015-09-28.09 H 17.21 0.06 1.03 0.94
2015-09-28.11 Ks 15.34 0.08 1.05 0.78
The observed colors of the object are summarized below:
UT J-H H-Ks J-Ks
2015-09-28.09 1.69 ± 0.13 1.864 ± 0.102 3.55 ± 0.15
We observe no significant variations (within the error bars) of the colors of the transient, compared to the previous observation on 2015-09-03UT (ATel #8059), however there is a general decrease of the NIR brightness (0.27 ± 0.09 mag in H band).
