GIT observations of AT 2025nsa in M31
ATel #17241; Shatakshi Chamoli (IIA), Judhajeet Basu (IIA), Sudhanshu Barway (IIA), G. C. Anupama (IIA), Aditya Pawan Saikia (IITB), Varun Bhalerao (IITB) and GIT Team
on 23 Jun 2025; 12:41 UT
Credential Certification: Judhajeet Basu (judhajeet.basu@iiap.res.in)
Subjects: Optical, Cataclysmic Variable, Nova, Transient
We report optical photometric observations of the nova AT 2025nsa (R.A. = 00:42:17.341, DEC= +41:08:55.23, Discovery Date: 2025-06-17.1498) by the GROWTH-India Telescope (GIT). This nova was discovered by GOTO group and reported on TNS. Claudio Balcon classified it as a nova in its Fe ll phase, noting prominent Balmer lines and the characteristic “Fe II forest” emission (classification reported on TNS).
The nova was detected across g’, r’, i’ and z’ bands in 360s exposure frames. The PSF photometry magnitudes (AB), calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction are:
Obs date (UTC) |filter | Mag ± error (AB)
2025-06-19.867 | g' | 16.97 ± 0.12
2025-06-19.863 | r' | 16.79 ± 0.11
2025-06-19.859 | i' | 16.59 ± 0.16
2025-06-20.858 | g' | 17.33 ± 0.17
2025-06-20.863 | r' | 17.19 ± 0.21
2025-06-20.854 | i' | 17.14 ± 0.91
2025-06-20.867 | z' | 16.50 ± 0.25
We note that the nova is brighter in the redder bands. Follow-up observations are being undertaken to understand the nature of this object.
The GROWTH-India Telescope (GIT; Kumar et al. 2022) 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 https://sites.google.com/view/growthindia/.
