A descriptive title

ATel #17444; G. J. M. Luna (UNAHUR/CONICET/Argentina), K. L. Page (U. Leicester), K. Sokolovsky (TTU)
on 14 Oct 2025; 14:05 UT
Credential Certification: Gerardo Juan Manuel Luna (juan.luna@unahur.edu.ar)

Tweet

Nova Cen 2025 (V1935 Cen/PNV J14372177-5847400) was reported in outburst when it reached magnitude 6.2 on 2025-09-22.396 UT (discovered by John Seach). Fermi-LAT detected the nova on 2025-09-21.50, prior to the optical discovery (ATel #17414). An early Swift/XRT observation reported by Sokolovsky et al. (Atel #17418) detected bright, hot and hard X-ray emission that most likely arose from shocks between the fast ejecta and the red giant wind of the cold companion. The recent observation with Swift/XRT in PC mode on October 9th yielded not only the detection of the aforementioned hard X-ray emission but also a soft component. The composite spectrum can be modeled with a blackbody-like component with kT = 40 +9/-7 eV plus a single optically thin thermal plasma, APEC, with kT = 1.06 +/- 0.07 keV, both absorbed through a column NH = (7.2 +2.4-2.5)e21 cm^-2. The observed flux in the 0.3-10 keV energy range was 1.4e-11 erg cm^-2 s^-1. The UVOT telescopes measure a UVW2 magnitude of 11.06+/-0.06. We thank the Swift PI, Brad Cenko, and his deputies for approving the time, as well as the Swift planning and operations teams for their continuing support.