An extremely hot white dwarf with a rapidly rotating K-type subgiant companion: UCAC2 46706450
CovenanteeEberhard Karls Universität Tübingen; Universität Potsdam; Institut d'Estudis Espacials de Catalunya; National Astronomical Research Institute of Thailand; Zhongguo ke xue yuan
Rights accessOpen Access
The subgiant UCAC2 46706450 is a late-type star with an ultraviolet (UV) excess. It was considered as a candidate to establish a sample of stars of spectral type F, G, and K with white dwarf (WD) companions that could be used to test binary evolution models. To verify the WD nature of the companion, UV spectroscopy has previously been performed by other authors. Via a detailed modelatmosphere analysis, we show that the UV source is an extremely hot WD with an effective temperature of Teff = 105 000 ± 5000 K, mass of M/M = 0.54 ± 0.02, radius of R/R = 0.040+0.005 -0.004, and luminosity of L/L = 176+55 -49, meaning that the compact object is just about to enter the WD cooling sequence
CitationWerner, K. [et al.]. An extremely hot white dwarf with a rapidly rotating K-type subgiant companion: UCAC2 46706450. "Astronomy & astrophysics", 1 Octubre 2020, vol. 642, núm. A228, p. 1-13.