Spectroscopic Classification of ASASSN-25cm as a Classical Nova

Summary

Spectroscopic Classification of ASASSN-25cm (=AT 2025nlr) as a Classical Nova ATel #17228; Yusuke Tampo (South African Astronomical Observatory, University of Cape Town) on 14 Jun 2025; 18:26 UTDistributed as an Instant Email Notice NovaeCredential Certification: Yusuke Tampo (yusuke@saao.ac.za) Subjects: Optical, Binary, Cataclysmic Variable, Nova, Transient, Variables I report the spectroscopic classification of ASASSN-25cm (=AT 2025nlr). Its optical spectrum was obtained on 2025-06-14.745 UT by the Mookodi (Erasmus et al. 2024) mounted on the 1-m Lesedi telescope at the South African Astronomical Observatory in Sutherland. The observation setups were 2" slit, wavelength coverage 4000-8000Å, and spectral resolution R~400. As reported to TNS, ASASSN-25cm was originally discovered by ASAS-SN on 2025-06-12 20:52:48 UT at g=8.7 mag. There is no counterpart in archival photometric surveys. My normalized spectrum shows the Balmer and either He I or Fe II lines with P Cygni profiles. The absorption minimum of the P Cygni profile in Hα and Hβ are located around -1200 and -900 km/s, respectively. Combining these spectral features and its large eruption amplitude, I conclude that this object is a new classical nova. Mookodi/Lesedi spectrum