Three X-ray Flares Near Primary Eclipse of the RS CVn Binary XY UMa

Abstract

We report on an archival X-ray observation of the eclipsing RS CVn binary XY UMa (${\mathrm{P}}_{\mathrm{orb}}\approx$ 0.48d). In two $\text{Chandra}$ ACIS observations spanning 200 ks and almost five orbital periods, three flares occurred. We find no evidence for eclipses in the X-ray flux. The flares took place around times of primary eclipse, with one flare occurring shortly ($<0.125{\mathrm{P}}_{\mathrm{orb}}$) after a primary eclipse, and the other two happening shortly ($<0.05{\mathrm{P}}_{\mathrm{orb}}$) before a primary eclipse. Two flares occurred within roughly one orbital period ($\Delta \varphi \approx 1.024{\mathrm{P}}_{\mathrm{orb}}$) of each other. We analyze the light curve and spectra of the system, and investigate coronal length scales both during quiescence and during flares, as well as the timing of the flares. We explore the possibility that the flares are orbit-induced by introducing a small orbital eccentricity, which is quite challenging for this close binary.

arXiv comment13 pages, 2 figures, RAA accepted

References in corpus (20)

• Collisional Plasma Models with APEC/APED: Emission Line Diagnostics of Hydrogen-like and Helium-like Ions
• Shrinking binary and planetary orbits by Kozai cycles with tidal friction
• The stellar activity-rotation relationship and the evolution of stellar dynamos
• Tertiary companions to close spectroscopic binaries
• EUV Flare Activity in Late-Type Stars
• Generalized investigation of the rotation-activity relation: Favouring rotation period instead of Rossby number
• Connecting Flares and Transient Mass Loss Events in Magnetically Active Stars
• Are superflares on solar analogues caused by extra-solar planets?
• On the sizes of stellar X-ray coronae
• Observational Evidence for Tidal Interaction in Close Binary Systems
• Warm Jupiters Need Close "Friends" for High-Eccentricity Migration -- A Stringent Upper Limit on the Perturber's Separation
• Diagnostics of stellar flares from X-ray observations: from the decay to the rise phase
• An Observational Study of Tidal Synchronization in Solar-Type Binary Stars in the Open Clusters M35 and M34
• Extreme X-ray Behavior of the Low-Luminosity Active Nucleus in NGC 4395
• Radial Velocity Studies of Close Binary Stars. XII
• Interacting coronae of two T Tauri stars: first observational evidence for solar-like helmet streamers
• X-ray Doppler Imaging of 44i Boo with Chandra
• The Young Binary DQ Tau: A Hunt For X-ray Emission From Colliding Magnetospheres
• X-ray Spectroscopy of the Contact Binary VW Cephei
• The Triply Eclipsing Hierarchical Triple Star KIC002856960

Cited by in corpus (3)

• The RS CVn type star GT Mus shows most energetic X-ray flares throughout the 2010s
• Swift and XMM-Newton observations of an RS CVn type eclipsing binary SZ Psc: Superflare and coronal properties
• An X-ray study of coronally connected active eclipsing binaries