SALT Spectroscopic classification of ASASSN-18lw as a dwarf nova
ATel #11712; D. A. H. Buckley (SAAO), M. Gromadzki (Warsaw), Subo Dong (KIAA-PKU), K. Z. Stanek (OSU)
on 13 Jun 2018; 05:22 UT
Credential Certification: Subo Dong (dongsubo@pku.edu.cn)
Subjects: Optical, Cataclysmic Variable
ASASSN-18lw (AT 2018cgo; RA: 19:28:50.74 Dec: -19:32:54.02) was discovered by the All Sky Automated Survey for SuperNovae (ASAS-SN, Shappee et al. 2014) on 2018 June 5.92 UT. It was observed with the Southern African Large Telescope (SALT) using the Robert Stobie Spectrograph on 2018 June 10.92 UT (HJD 2458280.4297) employing the PG300 lines/mm grating. A 1200s exposure spectrum, covering 3400 - 9000 Angstroms at a resolution of ~18 Angstroms with a 1.5 arcsec slit, was obtained in clear conditions with 1.2 arcsec seeing. The spectrum shows a very blue continuum with broad but shallow H I Balmer absorption lines, with H-alpha showing an emission reversal in the core. We interpret the spectrum to be that of a Dwarf Nova in early decline from outburst, which is consistent with the ASAS-SN g-band light curve.
