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Related papers: Radial velocity study of the CP star Epsilon Ursae…

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Context: For the past 3 years we have been monitoring a sample of 62 K giant stars using precise stellar radial velocity measurements taken at the Thueringer Landessternwarte Tautenburg. Aims: To search for sub-stellar companions to giant…

Observations of Epsilon UMa obtained with the star tracker on the Wide Field Infrared Explorer (WIRE) satellite during a month in mid-2000 are analyzed. This is one of the most precise photometry of an Ap star. The amplitude spectrum is…

Astrophysics · Physics 2009-11-10 Alon Retter , Timothy R. Bedding , Derek L. Buzasi , Hans Kjeldsen , Laszlo L. Kiss

We report that the spectroscopic binary ? Ursae Majoris (?mu UMa) has secondary RV variations of 471.2 days in addition to those of 230.0 days already known. Keplerian orbit analysis yields stellar mass companions of 1.6 M_Sun for the 230-d…

Solar and Stellar Astrophysics · Physics 2016-04-20 Byeong-Cheol Lee , Inwoo Han , Myeong-Gu Park , David E. Mkrtichian , Artie P. Hatzes , Gwanghui Jeong , Kang-Min Kim

We present here the detection of a brown dwarf orbiting the A9V star HD180777. The radial velocity measurements, obtained with the ELODIE echelle spectrograph at the Haute-Provence Observatory, show a main variation with a period of 28.4…

Astrophysics · Physics 2009-11-11 F. Galland , A. M. Lagrange , S. Udry , J. L. Beuzit , F. Pepe , M. Mayor

Aims. Our aim is to search for and study the origin of the low-amplitude and long-periodic radial velocity (RV) variations in K giants. Methods. We present high-resolution RV measurements of K2 giant epsilon CrB from February 2005 to…

Solar and Stellar Astrophysics · Physics 2015-06-11 Byeong-Cheol Lee , Inwoo Han , Myeong-Gu Park , David E. Mkrtichian , Kang-Min Kim

We report photometric and spectroscopic observations of the SU UMa-type dwarf novae, KS Ursae Majoris, during its 2003 February superoutburst. Modulations with a period of $0.07017\pm0.00021$ day, which is 3.3% larger than the orbital…

Astrophysics · Physics 2008-11-26 Yinghe Zhao , Zongyun Li , Xiaoan Wu , Qiuhe Peng , Zhousheng Shang , Zili Li

Using phase resolved spectroscopic observations obtained with the Ultraviolet and Visual Echelle Spectrograph on ESO's Kueyen Very Large Telescope supplemented by spectroscopic observations obtained with the Boller and Chivens Spectrograph…

Astrophysics · Physics 2009-11-07 Peter G. Jonker , Michiel van der Klis , Paul J. Groot

High-resolution spectroscopic observations of the W UMa-type binary Epsilon CrA obtained as a time monitoring sequence on four full and four partial nights within two weeks have been used to derive orbital elements of the system and discuss…

Solar and Stellar Astrophysics · Physics 2020-08-19 Slavek M. Rucinski

We report the detection of an exoplanet candidate in orbit around sigma Persei from a radial velocity (RV) survey. The system exhibits periodic RV variations of 579.8 +/- 2.4 days. The purpose of the survey is to search for low-amplitude…

Solar and Stellar Astrophysics · Physics 2017-01-18 Byeong-Cheol Lee , Inwoo Han , Myeong-Gu Park , David E. Mkrtichian , Gwanghui Jeong , Kang-Min Kim , Gennady Valyavin

We measured the radial-velocity curve of HD77581, the B-supergiant companion of the X-ray pulsar Vela X-1, using 183 high-resolution optical spectra obtained in a nine-month campaign. We derive radial-velocity amplitudes for different lines…

Astrophysics · Physics 2009-11-07 O. Barziv , L. Kaper , M. H. van Kerkwijk , J. H. Telting , J. van Paradijs

We report on the discovery of a planetary companion candidate with a minimum mass Msini = 4.6 M_J orbiting the K2 III giant star HD 175370 (KIC 007940959). This star was a target in our program to search for planets around a sample of 95…

We report spectroscopy of the newly discovered SU Ursae Majoris dwarf nova identified with the x-ray source RXS J053234.9+624755. Radial velocities of the H-alpha emission line in the quiescent state give an orbital period of 0.05620(4) d…

Astrophysics · Physics 2009-11-11 Ann B. Kapusta , John R. Thorstensen

It has long been speculated that the observed periodic radial velocity pattern for the K giant Pollux might be explained in terms of an orbiting planetary companion. We have collected 80 high-resolution spectra for Pollux at Lick…

We simulate the light variability of the Ap star epsUMa using the observed surface distributions of Fe, Cr, Ca, Mn, Mg, Sr and Ti obtained with the help of Doppler Imaging technique. Using all photometric data available we specified light…

Solar and Stellar Astrophysics · Physics 2015-05-19 D. Shulyak , J. Krticka , Z. Mikulasek , O. Kochukhov , T. Luftinger

Radial velocity observations of K giants have revealed periodic variations for some of the stars. The periods range from approximately 180 to 1000 or more days with velocity amplitudes ranging from approximately 50 m/s to 500 m/s. Except…

Astrophysics · Physics 2007-05-23 Saskia Hekker , Sabine Reffert , Andreas Quirrenbach

We present precise stellar radial velocity measurements of Gamma Dra taken from 2003 to 2017. The data from 2003 to 2011 show coherent, long-lived variations with a period of 702 d. These variations are consistent with the presence of a…

In this Paper we report on optical spectroscopic observations of the low-mass X-ray binary 2S 0921-630 obtained with the Very Large Telescope. We found sinusoidal radial velocity variations of the companion star with a semi-amplitude of…

Astrophysics · Physics 2009-11-10 P. G. Jonker , D. Steeghs , G. Nelemans , M. van der Klis

Auns. The aim of our paper is to investigate the low-amplitude and long-period variations in evolved stars with a precise radial velocity (RV) survey. Methods. The high-resolution, the fiber-fed Bohyunsan Observatory Echelle Spectrograph…

Earth and Planetary Astrophysics · Physics 2014-07-02 B. -C. Lee , I. Han , M. -G. Park , D. E. Mkrtichian , A. P. Hatzes , K. -M. Kim

We present an analysis of CCD photometric observations of the eclipsing novalike cataclysmic variable DW UMa obtained in two different luminosity states: high and intermediate. The star presents eclipses with very different depth: ~1.2 mag…

Astrophysics · Physics 2009-11-10 V. Stanishev , Z. Kraicheva , H. M. J. Boffin , V. Genkov , C. Papadaki , S. Carpano

We present an analysis of the first far-ultraviolet observations of the SW Sextantis-type cataclysmic variable DW Ursae Majoris, obtained in November 2001 with the Far Ultraviolet Spectroscopic Explorer. The time-averaged spectrum of DW UMa…

Astrophysics · Physics 2009-11-10 D. W. Hoard , Paula Szkody , Cynthia S. Froning , Knox S. Long , Christian Knigge
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