A multiwavelength study of the hierarchical triple HD 181068: A test bed for studying star-planet-interaction?
arXiv:1408.2988 · doi:10.1051/0004-6361/201423879
Abstract
HD 181068 is the only compact, triply eclipsing, hierarchical triple system containing a giant star known to date. With its central, highly-active G-type giant orbited by a close pair of main-sequence dwarfs, the system is ideal to study tidal interactions. We carried out a multiwavelength study to characterize the magnetic activity of the HD 181068 system. To this end, we obtained in- and out-of-eclipse X-ray snapshots with XMM-Newton and an optical spectrum, which we analyzed along with the Kepler light-curve. The primary giant shows strong quiescent X-ray emission at a level of 2e31 ergs, an S-index of 0.41 +/- 0.01, and marked white-light flares releasing up to 6e38 erg in the Kepler-band. During the second X-ray observation, we found a three-times elevated -- yet decaying -- level of X-ray emission, which might be due to an X-ray flare. The high level of magnetic activity is compatible with the previously reported absence of solar-like oscillations in the giant, whose atmosphere, however, undergoes tidally-induced oscillations imposed by the changing configuration of the dwarf-binary. We found that the driving force exciting these oscillations is comparable to the disturbances produced by a typical hot Jupiter, making the system a potential test bed to study the effects of tidal interactions also present in planetary systems.
arXiv commentAccepted for publication in A&A
References in corpus (26)
- Analytic Lightcurves for Planetary Transit Searches
- Collisional Plasma Models with APEC/APED: Emission Line Diagnostics of Hydrogen-like and Helium-like Ions
- A Survey of Stellar Families: Multiplicity of Solar-Type Stars
- Kepler Mission Design, Realized Photometric Performance, and Early Science
- ELODIE metallicity-biased search for transiting Hot Jupiters II. A very hot Jupiter transiting the bright K star HD189733
- Superflares on Solar Type Stars Observed with Kepler I. Statistical Properties of Superflares
- The On/Off Nature of Star-Planet Interactions
- KOI-126: A Triply-Eclipsing Hierarchical Triple with Two Low-Mass Stars
- EUV Flare Activity in Late-Type Stars
- First Light Measurements with the XMM-Newton Reflection Grating Spectrometers: Evidence for an Inverse First Ionisation Potential Effect and Anomalous Ne A bundance in the Coronae of HR 1099
- Coronal Evolution of the Sun in Time: High-Resolution X-Ray Spectroscopy of Solar Analogs with Different Ages
- Evidence for the impact of stellar activity on the detectability of solar-like oscillations observed by Kepler
- Pre-Spectroscopic False Positive Elimination of Kepler Planet Candidates
- Coronal properties of planet-bearing stars
- The Mouse that Roared: A Superflare from the dMe Flare Star EV Lac detected by Swift and Konus-Wind
- HD 181068: A Red Giant in a Triply-Eclipsing Compact Hierarchical Triple System
- X-Ray Spectroscopy of II Pegasi: Coronal Temperature Structure, Abundances, and Variability
- Continuous heating of a giant X-ray flare on Algol
- A study of X-ray flares - II. RS CVn type Binaries
- Possible constraints on exoplanet magnetic field strengths from planet-star interaction
- The Coronae of AR Lac
- Dynamical masses, absolute radii and 3D orbits of the triply eclipsing star HD 181068 from Kepler photometry
- Simultaneous X-ray spectroscopy of YY Gem with Chandra and XMM-Newton
- Pulsation analysis and its impact on primary transit modeling in WASP-33
- Basal Chromospheric Flux and Maunder Minimum-type Stars: The quiet-Sun Chromosphere as a Universal Phenomenon
- Tidally Induced Oscillations and Orbital Decay in Compact Triple-Star Systems