The 'Giraffe': Discovery of a stripped red giant in an interacting binary with an ∼2 Mlower giant

T Jayasinghe; TA Thompson; CS Kochanek; KZ Stanek; DM Rowan; DV Martin; K El-Badry; PJ Vallely; JT Hinkle; D Huber; H Isaacson; J Tayar; K Auchettl; I Ilyin; AW Howard; C Badenes

Journal article

The 'Giraffe': Discovery of a stripped red giant in an interacting binary with an ∼2 Mlower giant

T Jayasinghe, TA Thompson, CS Kochanek, KZ Stanek, DM Rowan, DV Martin, K El-Badry, PJ Vallely, JT Hinkle, D Huber, H Isaacson, J Tayar, K Auchettl, I Ilyin, AW Howard, C Badenes

Monthly Notices of the Royal Astronomical Society | Published : 2022

DOI: 10.1093/mnras/stac2187

Abstract

We report the discovery of a stripped giant + lower giant Algol-type binary, 2M04123153+6738486 (2M0412), identified during a search for non-interacting compact object - star binaries. 2M0412 is an evolved (Teff, giant ≃ 4000 K), luminous (Lgiant ≃ 150 L ) red giant in a circular P = 81.2 d binary. 2M0412 is a known variable star previously classified as a semiregular variable. The cross-correlation functions of follow-up Keck/HIRES and LBT/Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) spectra show an radial velocity variable second component with implied mass ratio q = Mgiant/Mcomp ≃ 0.20 ± 0.01. The All-Sky Automated Survey for SuperNovae (ASAS-SN), Asteroid Terrestrial..

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