Oph ( Nova Oph 2002 ) : LARGE - AMPLITUDE SLOW NOVA WITH STRONG POST - OUTBURST OSCILLATIONS

V2540 Oph (Nova Oph 2002) was independently discovered by Katsumi Haseda and Yuji Nakamura at magnitude 9.0 on 2002 January 24 (Haseda et al. 2002). Retter et al. (2002) detected emission lines of hydrogen and Fe II, indicating that the object is an Fe II class nova caught in the early decline stage. Later examination of photographs revealed that the nova was already at magnitude 8.9 on 2002 January 19 (Seki et al. 2002). Since the detection of the outburst, the nova has been intensively monitored by a number of observers. Figure 1 shows the light curve constructed from visual, CCD V-band and photovisual observations reported to the VSNET Collaboration Superimposed on these oscillations, the nova showed a steady fade at 0.033 mag d −1. [This rate was determined using the data between 2452294 and 2452341, during which the general trend of the fading can be approximated by a single decline rate. The last part of the light curve, when the nova underwent a long-lasting brightening, was not used in this analysis. If we incorporate the last part of the light curve, the average decline rate becomes 0.013 mag d −1 , which may more severely constrain the following discussion]. By applying the recently calibrated relation (della Valle, Livio 1995) of absolute maximum magnitude vs rate-of-decline (MMRD) in classical novae, we obtain the expected absolute V-band maximum magnitude of M V =−7.0±0.5. We performed the accurate astrometry with the images obtained by Kyoto 0.30-m telescope taken on Mar. 8.23 UT, which revealed the position of the nova as: R.