Spectroscopic Classification of the Transient PNV J00420424+4042336 = AT 2021dcd as an Fe II-type Nova in M31
ATel #14412; Kenta Taguchi, Masayuki Yamanaka, Keisuke Isogai (Kyoto University), Claudio Balcon (ISSP)
on 20 Feb 2021; 14:01 UT
Credential Certification: Keisuke Isogai (isogai@kusastro.kyoto-u.ac.jp)
Subjects: Optical, Cataclysmic Variable, Nova, Transient
We report on a spectrum of the transient PNV J00420424+4042336 = AT 2021dcd, indicating that this object is a classical nova in M31. We obtained the spectrum from 2021-02-19.42 to 2021-02-19.44 UT by using a fiber-fed integral field spectrograph (KOOLS-IFU; Matsubayashi et al. 2019) mounted on the 3.8-m Seimei telescope (Kurita et al. 2020) at Okayama Observatory of Kyoto University.
As reported to CBAT, this transient was discovered by XOSS at 17.9 mag (unfiltered) on 2021-02-16.5716 UT. It was not detected on 2021-02-12.6492 by XOSS (limiting mag 19.5). After the discovery, it brightened to 17.1 mag (by XOSS, unfiltered) on 2021-02-17.5589 and to 16.5 mag (by Bernezzo Observatory, unfiltered) on 2021-02-17.8220.
Our spectrum shows clear Hα, Hβ, and Fe II emission lines. The central wavelengths of Hα and Hβ are ∼ 6550 Å and ∼ 4852 Å respectively. Their equivalent widths are ∼ 90 Å and ∼ 45 Å, and their FWHMs are ∼ 45 Å and ∼ 30 Å, respectively.
Based on the brightness and spectrum, we conclude that this object is an Fe II-type nova in M31. There is a Pan-STARRS source with i = 20.96 nearby this transient, however, we consider the source does not relate to this transient.
Our Spectrum
