New outburst of the young binary system Z CMa
ATel #6874; Hiroyuki Maehara, Nobuharu Ukita (Okayama Astrophysical Observatory, NAOJ)
on 5 Jan 2015; 09:07 UT
Credential Certification: Hiroyuki Maehara (h.maehara@oao.nao.ac.jp)
Subjects: Optical, Variables, Young Stellar Object, Pre-Main-Sequence Star
We report the detection of a new outburst of Z CMa. According to the photometric data from the Kamogata-Kiso-Kyoto Wide-field Survey (KWS; f.l.=105mm lens + SBIG ST-8XME CCD Camera) database, V- and Ic-band fluxes of the object have gradually increased since around 2014 December 13, and reached 9.6 mag in V-band and 8.2 mag in Ic-band on 2015 January 02.641. The recent KWS data and light curve of the object are available at http://kws.cetus-net.org/~maehara/VSdata.py?object=CMAZ&plot=1&recent=1.
We obtained a high-resolution spectrum of the object with the 188-cm telescope and the High-Dispersion Echelle Spectrograph (Kambe et al. 2013, PASJ 65, 15) at Okayama Astrophysical Observatory on 2014 December 29.599. The spectrum shows the Balmer-series and FeII (multiplets 37, 38, 40, 41, 42, 43, 46, 48, 49, 55, 73 and 74) emission lines. NaI D1 and D2 lines are also in emission with narrow absorption cores. H-alpha, H-beta, NaI D1, D2, and FeII multiplet 42 (492.4 and 501.8 nm) lines exhibit P-Cyg profiles. The absorption components are blue-shifted by about 130-600 km/sec. These line profiles were posted at the following website:
http://kws.cetus-net.org/~maehara/Z_CMa_20141229.html.
