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Related papers: The system parameters of the polars MR Ser and ST …

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High-dispersion time-resolved spectroscopy of the unique magnetic cataclysmic variable AE Aqr is presented. A radial velocity analysis of the absorption lines yields K_2 = 168.7+/- 1 km/s. Substantial deviations of the radial velocity curve…

Astrophysics · Physics 2009-11-13 J. Echevarria , R. Connon Smith , R. Costero , S. Zharikov , R. Michel

We study the absorption lines present in the spectra of the long-period cataclysmic variable GK Per during its quiescent state, which are associated with the secondary star. By comparing quiescent data with outburst spectra we infer that…

Astrophysics · Physics 2009-11-07 L. Morales-Rueda , M. D. Still , P. Roche , J. H. Wood , J. J. Lockley

Linares et al. (2016) obtained quasi-simultaneous g', r' and i-band light curves and an absorption line radial velocity curve of the secondary star in the redback system 3FGL J0212.1+5320. The light curves showed two maxima and minima…

High Energy Astrophysical Phenomena · Physics 2017-10-18 T. Shahbaz , M. Linares , R. P. Breton

We derive precise system parameters for the pre-cataclysmic binary, NN Ser. From light curve fitting we find an orbital inclination of i = 89.6 +/- 0.2 deg. From the HeII absorption line we find K_{WD}= 62.3 +/- 1.9 km/s. The…

Solar and Stellar Astrophysics · Physics 2011-11-24 S. G. Parsons , T. R. Marsh , C. M. Copperwheat , V. S. Dhillon , S. P. Littlefair , B. T. Gansicke , R. Hickman

We present spectroscopy and time-series photometry of the dwarf nova QZ Ser. The spectrum shows a rich absorption line spectrum of type K4 +- 2. K-type secondary stars are generally seen in dwarf novae with orbital periods P-orb around 6 h,…

Astrophysics · Physics 2009-11-07 J. R. Thorstensen , W. H. Fenton , J. O. Patterson , J. Kemp , J. Halpern , I. Baraffe

High-dispersion spectroscopy of EY Cyg obtained from data spanning twelve years show, for the first time, the radial velocity curves from both emission and absorption line systems, yielding semi-amplitudes K_{em}=24+/- 4 km s^-1 and…

Astrophysics · Physics 2009-11-11 J. Echevarria , R. Michel , R. Costero , S. Zharikov

We present new optical spectroscopy of the eclipsing binary pulsar Sk 160/SMC X-1. From the He I absorption lines, taking heating corrections into account, we determine the radial velocity semi-amplitude of Sk 160 to be 21.8 +/- 1.8 km/s.…

Astrophysics · Physics 2007-05-23 A. K. F. Val Baker , A. J. Norton , H. Quaintrell

We present orbit-resolved spectroscopic and photometric observations of the polar ST LMi during its recent low and high states. In the low state spectra, we report the presence of blue and red satellites to the H-alpha emission line; the…

Astrophysics · Physics 2008-11-26 S. Kafka , S. B. Howell , R. K. Honeycutt , J. W. Robertson

We present phase-resolved low resolution infrared spectra of AM Her and ST LMi, two low-field polars that we observed with SPEX on the IRTF. Optical/NIR lightcurves are also published to help constrain the viewing geometry and brightness of…

Astrophysics · Physics 2009-11-13 Ryan K. Campbell , Thomas E. Harrison , Stella Kafka

New millisecond pulsars (MSPs) in compact binaries provide a good opportunity to search for the most massive neutron stars. Their main-sequence companion stars are often strongly irradiated by the pulsar, displacing the effective center of…

High Energy Astrophysical Phenomena · Physics 2018-05-24 Manuel Linares , Tariq Shahbaz , Jorge Casares

Orbital periods in AM Her stars (polars) are synchronized with spin periods of white dwarf by its high magnetic field. Since the last study of Porb distribution of these systems, the number of known objects of such type has more than…

Astrophysics · Physics 2010-05-28 Alex Golovin , Mykola Malygin , Elena Pavlenko

The mass-loss mechanism in normal K--M giant stars with small variability amplitudes is not yet understood, although they are the majority among red giant stars. We present high-spatial and high-spectral resolution observations of the 2.3…

Solar and Stellar Astrophysics · Physics 2015-06-03 K. Ohnaka , K. -H. Hofmann , D. Schertl , G. Weigelt , F. Malbet , F. Massi , A. Meilland , Ph. Stee

We use time-resolved spectra of the cataclysmic variable RW Tri in the I and K-band to determine the orbital velocity of the secondary star using skew mapping and cross correlation techniques respectively. We find radial velocity amplitudes…

Astrophysics · Physics 2009-11-07 T. Poole , K. O. Mason , G. Ramsay , J. E. Drew , R. C. Smith

We present time-resolved optical spectroscopy of the `redback' binary millisecond pulsar system PSR J1023+0038 during both its radio pulsar (2009) and accretion disc states (2014 and 2016). We provide observational evidence for the…

Solar and Stellar Astrophysics · Physics 2019-06-19 T. Shahbaz , M. Linares , P. Rodriguez-Gil , J. Casares

We present GTC-OSIRIS phase-resolved optical spectroscopy of three compact binary MSPs, or 'spiders': PSR J1048+2339, PSR J1810+1744, and (for the first time) PSR J1908+2105. For the companion in each system, the temperature is traced…

High Energy Astrophysical Phenomena · Physics 2025-01-08 Jordan A. Simpson , Manuel Linares , Jorge Casares , Tariq Shahbaz , Bidisha Sen , Fernando Camilo

We present optical spectroscopy and extensive $RI$ differential photometry of the double-lined eclipsing binary NSVS 02502726 (2MASS J08441103+5423473). Simultaneous solution of two-band light curves and radial velocities permits…

Solar and Stellar Astrophysics · Physics 2009-11-13 O. Cakirli , C. Ibanoglu , C. Gungor

We have measured 21-cm absorption spectra in the direction of three southern pulsars, PSRs B0736-40, B1451-68 and B1641-45, in three separate epochs spread over 2.5 yr. We see no evidence for any changes in the absorption spectra over this…

Astrophysics · Physics 2009-11-07 Simon Johnston , Baerbel Koribalski , Warwick Wilson , Mark Walker

Reliable determination of the basic physical properties of hot emission-line binaries with Roche-lobe filling secondaries is important for developing the theory of mass exchange in binaries. It is a very hard task, however, which is…

EX Hya is one of the few double-lined eclipsing cataclysmic variables that allow an accurate measurement of the binary masses. We analyze orbital phase-resolved UVES/ VLT high resolution spectroscopic observations of EX Hya with the aims of…

Astrophysics · Physics 2008-02-19 K. Beuermann , K. Reinsch

We report on optical spectroscopy of the eclipsing Halo LMXB 2S0921-630, that reveals the absorption line radial velocity curve of the K0III secondary star with a semi-amplitude K_2=92.89 +/- 3.84 km/s, a systemic velocity $\gamma$=34.9 +/-…

Astrophysics · Physics 2009-11-10 T. Shahbaz , J. Casares , C. Watson , P. A. Charles , R. I. Hynes , S. C. Shih , D. Steeghs
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