MACHO 311.37557.169: A VY Scl star. Issue 3 (14th April 2020)

• Record Type: Journal Article
• Authors: Wörpel, Hauke; Schwope, Axel D.; Traulsen, Iris; Brown, Michael J. I.
• Is Part Of: Astronomische Nachrichten. Volume 341:Issue 3(2020)
• Page Start: 283
• Page End: 290
• Publication Date: 2020-04-14
• Subjects: stars: Cataclysmic variables -- stars: Close binaries -- X‐rays: Binaries; Astronomy -- Periodicals; 520.5
• DOI: 10.1002/asna.202013531
• Languages: English
• ISSNs: 0004-6337

Abstract

Abstract: Optical surveys, such as the MACHO project, often uncover variable stars whose classification requires follow‐up observations by other instruments. We performed X‐ray spectroscopy and photometry of the unusual variable star MACHO 311.37557.169 with XMM‐Newton in April 2018, supplemented by archival X‐ray and optical spectrographic data. The star has a bolometric X‐ray luminosity of about 1 × 10 32 erg s −1 cm −2 and a heavily absorbed two‐temperature plasma spectrum. The shape of its light curve, its overall brightness, its X‐ray spectrum, and the emission lines in its optical spectrum suggest that it is most likely a VY Scl cataclysmic variable.