Fermi-LAT Gamma-ray Detection of the Nova in Centaurus PNV J14372177-5847400
ATel #17414; C. C. Cheung (NRL), G. La Mura (INAF - Astronomical Observatory of Cagliari), G. Marti-Devesa, F. Longo (University of Trieste and INFN Trieste), on behalf of the Fermi Large Area Telescope Collaboration
on 23 Sep 2025; 15:04 UT
Credential Certification: Teddy Cheung (Teddy.Cheung@nrl.navy.mil)
Subjects: Gamma Ray, >GeV, Nova, Transient
The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope, has detected gamma-ray emission from a source positionally consistent with PNV J14372177-5847400, discovered by J. Seach on 2025 Sep 22.3965 UT at 6.2 mag and spectroscopically confirmed as a classical nova by R. Kaufman (http://www.cbat.eps.harvard.edu/unconf/followups/J14372177-5847400.html). The optical source was not detected to a limiting magnitude of 11.0 on 2025 Sep 21.3660.
Preliminary analysis of LAT data using 6-hr time bins spanning 2025 Sep 21.0 to 23.0 indicates the onset of gamma-ray emission in the Sep 21.50-21.75 bin, i.e., prior to the optical discovery. Summing the 24-hr of data from Sep 21.5-22.5 results in a >5-sigma significance detection with a (E >100 MeV) flux of (1.0 +/- 0.3) x 10^-6 photons cm^-2 s^-1 and a photon index = 2.1 +/- 0.2 (statistical uncertainties only).
Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. In consideration of the ongoing activity of this source, we encourage multi-wavelength observations. For this source the Fermi LAT contact person is C.C. Cheung (Teddy.Cheung@nrl.navy.mil).
The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
