Pre-discovery detection and follow-up observations of AT 2017jdm; the likely recurrent nova M31N 2007-10b
ATel #11091; Hanjie Tan (Chinese Culture University), Xing Gao (Xinjiang Astronomical Observatory), Christopher Lloyd (University of Sussex)
on 26 Dec 2017; 12:56 UT
Credential Certification: Christopher Lloyd (c.lloyd@sussex.ac.uk)
Subjects: Optical, Nova, Transient
We have observed the outburst of AT 2017jdm discovered by F. Castellani et al.,
(2017, TNS Discovery report),
with 35-cm telescope and 60-cm telescope at Xingming Observatory. The measured position of AT 2017jdm is 00 43 29.461
+41 17 13.68, is only 0.3 arcsec from M31N 2007-10b, and suggests that it is most likely a recurrent outburst of
M31N 2007-10b (ATel #11088).
The object was already in outburst at magnitude 19.1±0.2 on 2017-12-24.568 (UT) and was detected on 2017-12-24.585
(UT) at 18.10 ±0.05, showing a rapid rise in brightness. These data are 0.1 day prior to the discovery date given
in TNS. AT 2017jdm was not detected on images obtained on 2017-12-23.713 and before, brighter than magnitude 19.2.
The nova was still visible on B-band and V-band images taken on 2017-12-25.664 and 2017-12-25.671 with the 60-cm telescope,
but had faded by about one magnitude over the previous day.
Our pre-discovery and follow-up observations are as follows:
| Date | Telescope | Filter | Photometry |
| 2017 12 23.713 | 35-cm | none | >19.2CV |
| 2017 12 24.568 | 35-cm | none | 19.1±0.2CV |
| 2017 12 24.585 | 60-cm | none | 18.10±0.05CV |
| 2017 12 25.664 | 60-cm | B | 19.23±0.08 |
| 2017 12 25.671 | 60-cm | V | 19.40±0.11 |
Photometry is based on the APASS catalogue (V, B magnitudes).
Further observations are encouraged.
This work is based on observations made with the 35-cm Telescope and 60-cm telescope (NEXT) operated on Xingming
Observatory (IAU Code C42) located at Nanshan, Xinjiang, China. tde NEXT telescope is a 60-cm Ritchey-Chretien F/8.0
telescope owned by Ningbo Bureau of Education and Xinjiang observatory.
