RE 0618 + 7 5 - A very short-period, binary dMe system

Jeffries, R.D.; Elliott, K.H.; Kellett, B.J.; Bromage, G.E.

Abstract

We report on the discovery of a new, very short-period, chromospherically active, late-type binary system. Observations performed with the ROSAT Wide Field Camera revealed the EUV source RE 0618 + 75, and subsequent optical spectroscopy identified this source as a chromospherically active, double dMe star with intense Ca II H and K and Hα emission lines. Further spectroscopy revealed that the object is a binary system with a period of 0.539 d, a mass ratio of unity and a systemic velocity of – 14 km s–1. Spectral types of M3 for both components are deduced from low-resolution spectra, and this yields a system inclination of 34° and component separation of 2.4 R⊙. RE 0618 + 75 is the most rapidly rotating, binary dMe system known, yet the magnetic activity observed is no greater than many similar, but more slowly rotating, dMe stars. This reinforces the concept of activity saturation in rapidly rotating stars.

Citation

Jeffries, R., Elliott, K., Kellett, B., & Bromage, G. (1993). RE 0618 + 7 5 - A very short-period, binary dMe system. Monthly Notices of the Royal Astronomical Society, 265(1), https://doi.org/10.1093/mnras/265.1.81

• Journal Article Type: Article
• Acceptance Date: May 10, 1993
• Online Publication Date: Nov 1, 1993
• Publication Date: 1993-11
• Deposit Date: Feb 8, 2024
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 265
• Issue: 1
• DOI: https://doi.org/10.1093/mnras/265.1.81
• Publisher URL: https://academic.oup.com/mnras/article/265/1/81/975268