KSP-OT-201611a: A Distant Population II Dwarf Nova Candidate Discovered by the KMTNet Supernova Program

Abstract

We present a multi-color, high-cadence photometric study of a distant dwarf nova KSP-OT-201611a discovered by the Korea Microlensing Telescope Network Supernova Program. From October 2016 to May 2017, two outbursts, which comprises a super/long outburst followed by a normal/short outburst separated by $\sim$91 days, were detected in the $BVI$ bands. The shapes and amplitudes of the outbursts reveal the nature of KSP-OT-201611a to be an SU UMa- or U Gem-type dwarf nova. Color variations of periodic humps in the super/long outburst possibly indicate that KSP-OT-201611a is an SU UMa-type dwarf nova. The super and normal outbursts show distinctively different color evolutions during the outbursts due most likely to the difference of time when the cooling wave is formed in the accretion disk. The outburst peak magnitudes and the orbital period of the dwarf nova indicate that it is at a large Galactocentric distance ($\sim$13.8 kpc) and height ($\sim$1.7 kpc) from the Galactic plane. KSP-OT-201611a, therefore, may provide a rare opportunity to study the accretion disk process of Population II dwarf novae.

12 pages, 11 figures, 4 tables, accepted to ApJ

References in corpus (10)

• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• No cataclysmic variables missing: higher merger rate brings into agreement observed and predicted space densities
• The chemical composition of red giants in 47 Tucanae I: Fundamental parameters and chemical abundance patterns
• The Galactic Thick Disc density profile traced with RR Lyrae stars
• Dwarf Galaxy Discoveries from the KMTNet Supernova Program I. The NGC 2784 Galaxy Group
• Tracing the Spiral Structure of the Outer Milky Way with Dense Atomic Hydrogen Gas
• The dwarf nova SS Cygni: what is wrong?
• The remarkable outburst of the highly evolved post-period-minimum dwarf nova SSS J122221.7-311525
• Abundance Derivations for the Secondary Stars in Cataclysmic Variables from Near-Infrared Spectroscopy
• Galactic model parameters of cataclysmic variables: Results from a new absolute magnitude calibration with 2MASS and WISE

Cited by in corpus (3)

• 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
• An extremely fast fading population II dwarf nova candidate: caught spectroscopically on the rise