Yuji Nakamura (Kameyama, Mie, Japan) has reported the discovery of a possible nova, PNV J23244760+6111140, on March 18.4236 2021.
ATel #14471 reports spectroscopic classification of the object as a classical nova (Hiroyuki Maehara (National Astronomical Observatory of Japan), Kenta Taguchi (Kyoto University), Yusuke Tampo (Kyoto University), Naoto Kojiguchi (Kyoto University), Keisuke Isogai (Kyoto University).
The spectrum shows prominent Balmer series and He I emission lines with P-Cyg profiles. The absorption component of P-Cyg profile in He I 5876 line is blue-shifted by ~1600 km/s with respect to the emission peak. He II 4686 and N III 4640 lines are also seen in emission. These features suggest that the object is a classical nova.
Nova Cas 2021 is at RA 23 24 47.73 Dec +61 11 14.8 (J2000.0)
Observation with C11 + LhiresIII with 2400l/mm grating and SX 814 ccd-camera for H-alpha detail @ 6562.801 Å.
Plot of the expansion speed of the ionised H-cloud in km/sec.