TY - JOUR
T1 - Spectroscopy, MOST photometry, and interferometry of MWC 314
T2 - Is it an LBV or an interacting binary?
AU - Richardson, Noel D.
AU - Moffat, Anthony F.J.
AU - Maltais-Tariant, Raphäel
AU - Pablo, Herbert
AU - Gies, Douglas R.
AU - Saio, Hideyuki
AU - St-Louis, Nicole
AU - Schaefer, Gail
AU - Miroshnichenko, Anatoly S.
AU - Farrington, Chris
AU - Aldoretta, Emily J.
AU - Artigau, Étienne
AU - Boyajian, Tabetha S.
AU - Gordon, Kathryn
AU - Jones, Jeremy
AU - Matson, Rachel
AU - McAlister, Harold A.
AU - O'Brien, David
AU - Raghavan, Deepak
AU - Ramiaramanantsoa, Tahina
AU - Ridgway, Stephen T.
AU - Scott, Nic
AU - Sturmann, Judit
AU - Sturmann, Laszlo
AU - Ten Brummelaar, Theo
AU - Thomas, Joshua D.
AU - Turner, Nils
AU - Vargas, Norm
AU - Zharikov, Sergey
AU - Matthews, Jaymie
AU - Cameron, Chris
AU - Guenther, David
AU - Kuschnig, Rainer
AU - Rowe, Jason
AU - Rucinski, Slavek
AU - Sasselov, Dimitar
AU - Weiss, Werner W.
PY - 2016/1/1
Y1 - 2016/1/1
N2 - MWC 314 is a bright candidate luminous blue variable (LBV) that resides in a fairly close binary system, with an orbital period of 60.753 ± 0.003 d. We observed MWC 314 with a combination of optical spectroscopy, broad-band ground- and space-based photometry, as well as with long baseline, near-infrared interferometry. We have revised the single-lined spectroscopic orbit and explored the photometric variability. The orbital light curve displays two minima each orbit that can be partially explained in terms of the tidal distortion of the primary that occurs around the time of periastron. The emission lines in the system are often double-peaked and stationary in their kinematics, indicative of a circumbinary disc. We find that the stellar wind or circumbinary disc is partially resolved in the K'-band with the longest baselines of the CHARA Array. From this analysis, we provide a simple, qualitative model in an attempt to explain the observations. From the assumption of Roche Lobe overflow and tidal synchronization at periastron, we estimate the component masses to be M1 ≈ 5M⊙ and M2 ≈15M⊙, which indicates a mass of the LBV that is extremely low. In addition to the orbital modulation, we discovered two pulsational modes with the MOST satellite. These modes are easily supported by a low-mass hydrogen-poor star, but cannot be easily supported by a star with the parameters of an LBV. The combination of these results provides evidence that the primary star was likely never a normal LBV, but rather is the product of binary interactions. As such, this system presents opportunities for studying mass-transfer and binary evolution with many observational techniques.
AB - MWC 314 is a bright candidate luminous blue variable (LBV) that resides in a fairly close binary system, with an orbital period of 60.753 ± 0.003 d. We observed MWC 314 with a combination of optical spectroscopy, broad-band ground- and space-based photometry, as well as with long baseline, near-infrared interferometry. We have revised the single-lined spectroscopic orbit and explored the photometric variability. The orbital light curve displays two minima each orbit that can be partially explained in terms of the tidal distortion of the primary that occurs around the time of periastron. The emission lines in the system are often double-peaked and stationary in their kinematics, indicative of a circumbinary disc. We find that the stellar wind or circumbinary disc is partially resolved in the K'-band with the longest baselines of the CHARA Array. From this analysis, we provide a simple, qualitative model in an attempt to explain the observations. From the assumption of Roche Lobe overflow and tidal synchronization at periastron, we estimate the component masses to be M1 ≈ 5M⊙ and M2 ≈15M⊙, which indicates a mass of the LBV that is extremely low. In addition to the orbital modulation, we discovered two pulsational modes with the MOST satellite. These modes are easily supported by a low-mass hydrogen-poor star, but cannot be easily supported by a star with the parameters of an LBV. The combination of these results provides evidence that the primary star was likely never a normal LBV, but rather is the product of binary interactions. As such, this system presents opportunities for studying mass-transfer and binary evolution with many observational techniques.
KW - Binaries: close-Stars: early-type-Stars
KW - Individual
KW - Massloss-Stars
KW - MWC 314-Stars
KW - S Doradus-Stars
KW - Variables
KW - winds-Outflows
UR - http://www.scopus.com/inward/record.url?scp=84958280087&partnerID=8YFLogxK
U2 - 10.1093/mnras/stv2291
DO - 10.1093/mnras/stv2291
M3 - Article
AN - SCOPUS:84958280087
SN - 0035-8711
VL - 455
SP - 244
EP - 257
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -