High resolution optical spectroscopy of nova Mus 2018 = PNV J11261220-6531086
ATel #11183; Terry C. Bohlsen (ARAS group, Mirranook Armidale,
on 17 Jan 2018; 11:52 UT
Distributed as an Instant Email Notice Novae
Credential Certification: S. N. Shore (shore@df.unipi.it)
Nova Muscae 2018 (PNV J11261220-6531086), discovered o 2018 Jan. 14.5 (V=7.0) was observed spectroscopically on 2018 Jan. 16.46 (MJD 58134.982), with a LHIRES spectrograph mounted on a C11 reflector (35micron slit, 2400 lines/mm, R > 11000) with a total exposure time of 1200 sec in the interval 6520-6690A. At the time, the AAVSO reported V ~ 7. The spectrum at Halpha shows a broad, optically thick emission profile with absorption components at -1540 and -650 km/s (the higher velocity is the broader component). Some residual emission is also visible beyond -1700 km/s. The redward emission wing extends to at least +2500 km/s, S/N is about 100 in the continuum, the emission being redward extended (skewed) and with peak intensity of about 10 (emission EW ~ 360 A). The He I 6678A line is not detected. The line profile and velocities are typical of the post-maximum stage of expansion, its brightness suggests this classical nova may also be detected at high energy, especially with Fermi. The nova is clearly still in its declining optically thick stage, the low resolution spectrum from Jan. 14 reported by Kaufman (AAVSO Alert 609) shows Balmer emission lines of comparable with to that described here. Further observations are encouraged.
ARAS Nova Database
