GIT observations of the M31 nova AT2024zaq
ATel #16884; Judhajeet Basu (IIA), Shatakshi Chamoli (IIA), Sudhanshu Barway (IIA), G. C. Anupama (IIA), Tanishk Mohan (IITB), Vishwajeet Swain (IITB), Varun Bhalerao (IITB), Kaisang Angail (IIA)
on 30 Oct 2024; 07:14 UT
Credential Certification: Judhajeet Basu (judhajeet.basu@iiap.res.in)
Subjects: Optical, Nova, Transient
We report optical photometric observations of the transient AT2024zaq discovered on 24.337 October 2024 at a clear filter magnitude of 16.2. The object is located 54 arcsec from the M31 center towards the north-east direction. Follow-up observations revealed strong Balmer emission features and Fe lines, classifying it as a nova in its Fe II phase (ATel #16883).
The object was detected in the M31 survey images of the 0.7 m GROWTH-India Telescope (GIT, Kumar et al. 2022 ) on 2024 Oct 26, 27, and 28. The photometry indicates that the object has faded to below 17 mags in both g' and r' filters. The nova initially declined from 15.94 (R) (ATel #16878) to 17.17 (r') in 1.8 days (24.75 to 26.57 Oct). In the next 2 days (26.57 to 28.60 Oct), the decline slowed down to 0.15 mags in the r' band. The g'-r' color has reddened during the observation period, which could be because of the increasing strength of the H alpha line.
The magnitude table is summarised below.
Obs date (UTC) |filter| Mag +/- error (AB)
2024-10-26.568 |r'| 17.17 +/- 0.11
2024-10-26.608 |g'| 17.24 +/- 0.20
2024-10-27.792 |g'| 17.51 +/- 0.16
2024-10-27.824 |r'| 17.29 +/- 0.14
2024-10-28.603 |r'| 17.32 +/- 0.12
2024-10-28.865 |g'| > 17.67
Such luminous novae in M31 are rare; hence, further spectroscopic and photometric observations are highly encouraged.
GIT is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at (GIT website) . We thank the HCT staff for their support during the observations. The Indian Astronomical Observatory is operated by the Indian Institute of Astrophysics, Bengaluru, India.
