Discovery of a rapid, luminous nova in NGC 300 by the KMTNet Supernova Program

Abstract

We present the discovery of a rapidly evolving transient by the Korean Microlensing Telescope Network Supernova Program (KSP). KSP is a novel high-cadence supernova survey that offers deep ($\sim 21.5$ mag in $BVI$ bands) nearly continuous wide-field monitoring for the discovery of early and/or fast optical transients. KSP-OT-201509a, reported here, was discovered on 2015 September 27 during the KSP commissioning run in the direction of the nearby galaxy NGC~300, and stayed above detection limit for $\sim$ 22 days. We use our $BVI$ light-curves to constrain the ascent rate, $-3.7(7)$ mag day${}^{-1}$ in $V$, decay time scale, $t_2^V=1.7(6)$ days, and peak absolute magnitude, $-9.65\le M_V\le -9.25$ mag. We also find evidence for a short-lived pre-maximum halt in all bands. The peak luminosity and lightcurve evolution make KSP-OT-201509a consistent with a bright, rapidly decaying nova outburst. We discuss constraints on the nature of the progenitor and its environment using archival HST/ACS images and conclude with a broad discussion on the nature of the system.

7 pages in aastex6 two-column format, 4 figures; accepted in ApJ

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Cited by in corpus (4)

• KSP-SN-2016kf: a long-rising H-rich Type II Supernova with unusually high ${}^{56}$Ni mass discovered in the KMTNet Supernova Program
• Dwarf Galaxy Discoveries from the KMTNet Supernova Program II. The NGC 3585 Group and Its Dynamical State
• Discovery of a Short-Period and Unusually Helium-Deficient Dwarf Nova KSP-OT-201701a by the KMTNet Supernova Program
• KSP-OT-201611a: A Distant Population II Dwarf Nova Candidate Discovered by the KMTNet Supernova Program