Research Note

Is KT Mon a classical nova?

¹ Department of Astronomy, Kyoto University, Kyoto 606-8502, Japan
² Faculty of Science, Kyushu University, Fukuoka 810-8560, Japan

Corresponding author: T. Kato, tkato@kusastro.kyoto-u.ac.jp

Received: 23 September 2002
Accepted: 15 October 2002

Abstract

KT Mon has been considered as a classical nova in 1942 based on its light curve and spectroscopy. However, we noticed a unusual feature for a nova soon after its maximum: the early presence of high excitation emission lines such as HeII and NIII. We propose previously overlooked interpretations that KT Mon can be either a WZ Sge-type dwarf nova and an X-ray transient, although the possibility of an unusual or a recurrent nova is not completely excluded. If KT Mon is a WZ Sge-type dwarf nova, the system is expected to have a brown dwarf secondary. If KT Mon is an X-ray transient, the system is a good candidate for the nearest black-hole binary. Within our knowledge, the observed features seem to more strongly support the latter possibility. In all possibilities, we can expect a recurrent outburst in meaningfully near future.