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Related papers: The first Doppler imaging of the active binary pro…

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We investigate the fast-rotating (P_orb=P_rot=0.465d), active dwarf binary V405 And (M0V+M5V) using photometric BV(RI)_C and optical spectroscopic data. The light variation is caused by the combined effect of spottedness and binarity with a…

Solar and Stellar Astrophysics · Physics 2009-09-28 K. Vida , K. Oláh , Zs. Kővári , H. Korhonen , J. Bartus , Zs. Hurta , K. Posztobányi

EL CVn-type eclipsing binaries are composed of a massive A-type main-sequence primary star and a hotter B-type secondary star. This paper presents the time-series photometric and asteroseismic results of the EL CVn-type star 1SWASP…

Solar and Stellar Astrophysics · Physics 2021-11-03 Seung-Lee Kim , Jae Woo Lee , Chung-Uk Lee , Yongseok Lee , Dong-Joo Lee , Kyeongsoo Hong , Sang-Mok Cha , Dong-Jin Kim , Byeong-Gon Park

Stellar activity is the main limitation to the detection of Earth-twins using the RV technique. Despite many efforts in trying to mitigate the effect of stellar activity using empirical and statistical techniques, it seems that we are…

Solar and Stellar Astrophysics · Physics 2018-12-05 Xavier Dumusque

We conducted high dispersion spectroscopic observations of 50 superflare stars with Subaru/HDS. These 50 stars were selected from the solar-type superflare stars that we had discovered from the Kepler data. More than half (34 stars) of…

Solar and Stellar Astrophysics · Physics 2015-06-09 Yuta Notsu , Satoshi Honda , Hiroyuki Maehara , Shota Notsu , Takuya Shibayama , Daisaku Nogami , Kazunari Shibata

We present the first maps of the surface magnetic fields of a pre-main sequence binary system. Spectropolarimetric observations of the young, 18 Myr, HD 155555 (V824 Ara, G5IV + K0IV) system were obtained at the Anglo-Australian Telescope…

Young, rapidly-rotating M dwarfs exhibit prominent starspots, which create quasiperiodic signals in their photometric and Doppler spectroscopic measurements. The periodic Doppler signals can mimic radial velocity (RV) changes expected from…

We present a spectroscopic/photometric analysis of the rapid rotator KIC8429280, discovered by ourselves as a very young star and observed by the Kepler mission. We use spectroscopic/photometric ground-based data to derive stellar…

Solar and Stellar Astrophysics · Physics 2015-05-28 A. Frasca , H. -E. Fröhlich , A. Bonanno , G. Catanzaro , K. Biazzo , J. Molenda-Zakowicz

(shortened for arXiv) We aim to progress towards more efficient exoplanet detection around active stars by optimizing the use of Doppler Imaging in radial velocity measurements. We propose a simple method to simultaneously extract a…

The eclipsing binary T-Cyg1-12664 was observed both spectroscopically and photometrically. Radial velocities of both components and ground-based VRI light curves were obtained. The Kepler's R-data and radial velocities for the system were…

Solar and Stellar Astrophysics · Physics 2015-06-11 O. Cakirli , C. Ibanoglu , E. Sipahi

The single-lined spectroscopic binary $\nu$ Octantis provided evidence of the first conjectured circumstellar planet demanding an orbit retrograde to the stellar orbits. The planet-like behaviour is now based on 1437 radial velocities (RVs)…

Earth and Planetary Astrophysics · Physics 2021-02-25 David Ramm , Paul Robertson , Sabine Reffert , Fraser Gunn , Trifon Trifonov , Karen Pollard , Faustine Cantalloube

We present comprehensive spectroscopic and photometric analysis of the detached eclipsing binary KIC 12418816, which is composed of two very similar and young main sequence stars of spectral type K0 on a circular orbit. Combining…

Solar and Stellar Astrophysics · Physics 2017-12-13 Hasan Ali Dal , Orkun Ozdarcan

We present Doppler imaging and a Balmer line analysis of the weak-line T Tauri star TWA 17. Spectra were taken in 2006 with the UCL Echelle Spectrograph on the Anglo-Australian Telescope. Using least-squares deconvolution to improve the…

Solar and Stellar Astrophysics · Physics 2015-05-13 M. B. Skelly , Y. C. Unruh , J. R. Barnes , W. A. Lawson , J. -F. Donati , A. Collier Cameron

AM CVn systems are a select group of ultracompact binaries with the shortest orbital periods of any known binary subclass; mass-transfer is likely from a low-mass (partially-)degenerate secondary onto a white dwarf primary, driven by…

We re-analyse spectropolarimetric data of AB Dor taken in 1996 December using a surface imaging code that can model the magnetic field of the star as a non-potential current-carrying magnetic field. We find that a non-potential field needs…

Astrophysics · Physics 2009-11-07 G. A. J. Hussain , A. A. van Ballegooijen , M. Jardine , A. Col lier Cameron

Since it has become possible to discovery planets orbiting nearby solar-type stars through very precise Doppler-shift measurements, the role of methods used to analyze such observations has grown significantly. The widely employed…

Astrophysics · Physics 2009-10-30 Maciej Konacki , Andrzej J. Maciejewski

We present a Roche tomography reconstruction of the secondary star in the cataclysmic variable AE Aqr. The tomogram reveals several surface inhomogeneities that are due to the presence of large, cool starspots. In addition to a number of…

Astrophysics · Physics 2009-11-11 C. A. Watson , V. S. Dhillon , T. Shahbaz

We present the results of our spectroscopic observations of eight detached eclipsing binaries (DEBs), selected from the $Kepler$ Eclipsing Binary Catalog. Radial velocities (RVs) were calculated from high resolution spectra obtained with…

Solar and Stellar Astrophysics · Physics 2017-04-19 K. G. Hełminiak , N. Ukita , E. Kambe , S. K. Kozłowski , P. Sybilski , H. Maehara , M. Konacki , R. K. Pawłaszek

This paper presents the analysis of Doppler p-modes of the F9 V star beta Virginis obtained with the spectrograph CORALIE in March 2003. Eleven nights of observations have made it possible to collect 1293 radial velocity measurements with a…

Astrophysics · Physics 2009-11-10 F. Carrier , P. Eggenberger , A. D'Alessandro , L. Weber

Doppler imaging, a technique which inverts spectral line profile variations of an Ap star into a two-dimensional abundance maps, provides new observational constraints on diffusion mechanism in the presence of a global magnetic field. A…

Astrophysics · Physics 2007-05-23 R. Kuschnig

The ubiquity of M dwarf stars combined with their low masses and luminosities make them prime targets in the search for nearby, habitable exoplanets. We investigate the effects of starspot-induced radial velocity (RV) jitter on detection…

Solar and Stellar Astrophysics · Physics 2015-06-23 Jan Marie Andersen , Heidi Korhonen