Spectroscopic Observations of V694 Mon (= MWC 560) during its recent outburst
ATel #12231; Alessandra Azzollini, Marco Bellomo, Giovanni Leidi, Tommaso Migliorini, Marco Monaci (Dept. of Physics, Univ. of Pisa), Peter Somogyi (Tata, Hungary and ARAS Group)
on 20 Nov 2018; 01:42 UT
Credential Certification: S. N. Shore (shore@df.unipi.it)
Subjects: Optical, Cataclysmic Variable, Star, Variables
Spectra were obtained on 2018 Nov. 19.1 UT at Pisa using a 280 cm C11 telescope with the LHIRES III at resolutions of about 1300 (total exposure time of 3600 sec; 4700-7700A) and 18000 (6430-6631A; total exposures times of 3600 sec at each resolution) and on 2018 Oct. 31.1 UT at Tata with a 30cm LH2400 telescope resolution of about16000 (6502-6611A; exposure time of 5400 sec), thus bracketing the observation reported in ATel #12227. The S/N ratio was > 10 in the continuum with the Halpha peak at about 40+/-2 times the continuum. The Halpha profile shows broad, extended wings at 10 to 15 percent of the peak intensity extending to +/-1000 km/s. The Oct 31 Halpha profile shows a superimposed absorption with a blue edge at -300 km/s that had weakened by Nov. 19 but with the blue side of the emission decidedly asymmetric compared to the red wing (reversal of the profile shows the absorption extends to nearly zero vrad). The low resolution spectrum shows little evidence other than profile asymmetry for absorption at Halpha and Hbeta, aside from a complex of Fe II emission lines there is a pronounced presence of the neutral He lines. He I 4922 and 5013 are much stronger than Fe II 4923 and 5018; Fe II 5169 is present but weak. He I 5013, 5876, and 6678 show P Cyg profiles, even at low resolution, with a similar blue absorption velocity to that of Halpha but with a higher absorption to emission ratio (of order unity, for 5876 and 6678 allowing for the resolution of about 5A, the absorption component is weaker on 5013). Na I is in absorption, providing a check on the reality of the absorption feature at low resolution. Si II 6347, 6371 may be present but the low resolution spectrum is not sufficiently high quality to be sure. [O I] 6300 is not detected nor are there other obvious forbidden lines, Observations will be continuing as weather permits. The spectra are available at the ARAS Database.
A.R.A.S Spectral Data Base - Eruptive stars section
