Abstract Details

Name: VIPIN KUMAR
Affiliation: Physical Research Laboratory, Ahmedabad, Gujarat
Conference ID: ASI2021_324
Title : Optical and near-infrared spectroscopy studies of a very slow Nova V2891 Cyg
Authors and Co-Authors : Vipin Kumar (Physical Research Laboratory, Ahmedabad), Mudit K. Srivastava (Physical Research Laboratory, Ahmedabad), Dipankar P.K. Banerjee (Physical Research Laboratory, Ahmedabad), Vishal Joshi (Physical Research Laboratory, Ahmedabad).
Abstract Type : Oral
Abstract Category : Stars, ISM and Galaxy
Abstract : Nova V2981 Cyg (also transient AT2019QWF) had been discovered in September 2019 and later classified as a nova of Fe II class. The subsequent photometric monitoring of the object revealed it to be a very slow nova with a rather unusual, nearly flat, light curve. Only a few novae prior to this have shown similar photometric behaviour, and its slow spectral evolution presented a rare opportunity to study such "flat-topped" novae. The multiple re-brightening in it light curve was found to be consistent with the idea of the periodic mass ejection, and there is evidence of a possible rare reverse hybrid transition (He/N to Fe II class) as noticed in its earliest optical/NIR spectra. While for a long time (~240 days) the optical spectra showed a slower spectral evolution, it eventually evolved into an emission rich nebular spectrum by May 2020. The coronal lines were seen in the spectrum of September 2020, thereby commence the coronal phase after a year of the outburst. The nova had been followed in optical wavelengths with indigenously developed MFOSC-P instrument on PRL 1.2m Mt. Abu telescope along with other facilities for its optical and near-infrared spectra of selected epochs. This 15 months-long observing campaign resulted in a wealth of information deduced preliminary from the optical/NIR spectroscopy. In this talk, we shall present a comprehensive spectroscopy study of the evolution of this nova V2891 Cyg over the last 15 months. This work has been done in collaboration with U.Munari, INAF, Italy; C.E. Woodward, Univ. of Minnesota, USA and A.Evans, Keele University, UK.