scholarly journals Red Spectroscopy of IP Pegasi

1987 ◽  
Vol 93 ◽  
pp. 145-149
Author(s):  
J.S. Martin ◽  
D.H.P. Jones ◽  
R.C Smith
Keyword(s):  
Radial Velocity ◽  
Cross Correlation ◽  
Main Sequence ◽  
Mass Function ◽  
Velocity Curve ◽  
Absorption Lines ◽  
Radial Velocity Curve ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Dwarf Nova

AbstractTime resolved spectroscopy of the dwarf nova IP Pegasi in the range λλ 7670–8320Å shows absorption lines originating from the cool secondary. A radial velocity curve for this component has been derived by cross-correlation with a normal M star. The curve has semi-amplitude K2 = 288.3 ± 4 km s−1, and is slightly distorted. This distortion is equivalent to an orbit with an apparent eccentricity of 0.075 ± 0.024. The mass function of the primary is 0.394 ± 0.016M⊙. From this we derive constraints on the component masses of 0.62 < M1 < 1.14M⊙ and 0.17 < M2 < 0.71M⊙. The red star has a radius in the range 0.32 < R2 < 0.51R⊙ and is probably on the main sequence.

scholarly journals Time-Resolved Spectroscopy and Doppler Tomography of UX UMa

2004 ◽  
Vol 194 ◽  
pp. 270-270 ◽  
Author(s):  
V. F. Suleimanov ◽  
V. V. Neustroev ◽  
N. V. Borisov ◽  
I. S. Fioktistova
Keyword(s):  
Radial Velocity ◽  
Emission Line ◽  
Orbital Period ◽  
Velocity Curve ◽  
Cataclysmic Variable ◽  
Radial Velocity Curve ◽  
Doppler Tomography ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Medium Resolution

Medium resolution spectroscopy of nova-like cataclysmic variable UX UMA was performed using the 6-m telescope SAO RAS in April 1999. Obtained spectra cover the total orbital period including eclipse phases and allow us to reproduce the radial velocity curve. The radial-velocity variations of the Hβ emission line are found to have semi-amplitude of about 100 km/s.

scholarly journals New Spectroscopic Observations of Dwarf Nova BZ Ursae Majoris with Extremely Unusual Emission Lines Profiles

2004 ◽  
Vol 194 ◽  
pp. 269-269 ◽  
Author(s):  
V. V. Neustroev ◽  
S. V. Zharikov ◽  
A. Medvedev ◽  
A. Shearer
Keyword(s):  
Radial Velocity ◽  
Emission Line ◽  
Velocity Curve ◽  
Emission Lines ◽  
Radial Velocity Curve ◽  
Dwarf Nova ◽  
Preliminary Results ◽  
Spectroscopic Observations ◽  
Medium Resolution ◽  
Hα Emission

We present preliminary results of new spectroscopic observations of dwarf nova BZ UMa in quiescence. Fifty medium resolution spectra allow us to reproduce the radial velocity curve from the Hα emission line. We confirm that BZ UMa shows extremely unusual emission lines profiles, Unlike the classical single or the double-peaked profiles usually observed in spectra of dwarf novae, emission lines of BZ UMa consist of at least five peaks.

scholarly journals A Tale on Two Close Binaries in Pegasus

2014 ◽  
Vol 23 (2) ◽  
Author(s):  
H. V. Şenavcı ◽  
M. Yılmaz ◽  
Ö. Baştürk ◽  
İ. Özavcı ◽  
Ş. Çalışkan ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Main Sequence ◽  
Curve Analysis ◽  
Velocity Curve ◽  
Close Binaries ◽  
Main Sequence Stars ◽  
Radial Velocity Curve ◽  
Contact Binaries ◽  
Effective Temperatures

AbstractWe present the simultaneous light and radial velocity curve analysis of two contact binaries in Pegasus using the Wilson-Devinney code. The following absolute astrophysical parameters are determined: masses, radii and effective temperatures. BB Peg is a W-subtype W UMa-type binary, components of which are main sequence stars with 0.50

scholarly journals Discrepant Measurements of the Radial Velocities of SS Cygni: Solution to the Problem

1987 ◽  
Vol 93 ◽  
pp. 113-118
Author(s):  
E.L. Robinson
Keyword(s):  
Radial Velocity ◽  
Accretion Disk ◽  
White Dwarf ◽  
Center Of Mass ◽  
Velocity Curve ◽  
Radial Velocities ◽  
Radial Velocity Curve ◽  
Dwarf Nova

AbstractWe show that the discrepancies among the various measurements of the radial velocity curve of the K5 V star in the dwarf nova SS Cyg have been caused by (1) poor choices of lines for measuring its velocity and (2) large distortions in its velocity caused by heating from the white dwarf and its accretion disk. The correct K velocity of the center of mass of the K5 V star is 158 ± 3 km s−1.

scholarly journals The Radial Velocity Curve of V652 Her (BD+13°3224)

1985 ◽  
Vol 87 ◽  
pp. 109-115
Author(s):  
P.W. Hill ◽  
C.S. Jeffery
Keyword(s):  
Radial Velocity ◽  
Time Resolution ◽  
High Frequency ◽  
Velocity Curve ◽  
Velocity Data ◽  
Effective Surface ◽  
Radial Velocity Curve ◽  
Minimum Radius ◽  
Helium Star ◽  
Radial Velocity Data

AbstractNew radial velocity data for the pulsating extreme helium star V652 Her (BD+13°3224) have been obtained with a time resolution of 100 s. High frequency structure in the radial velocity curve is detected, and a comparison with previous data suggests that the detailed shape of the velocity curve is variable. The data imply that the effective surface gravity must increase by a factor of 4 at minimum radius.

The radial-velocity curve of V1010 Ophiuchi - Orbital elements and the rotational disturbance

1988 ◽  
Vol 100 ◽  
pp. 371 ◽  
Author(s):  
Thaddeus F. Worek ◽  
Eugene R. Zizka ◽  
Merle W. King ◽  
Joost H. Kiewiet de Jonge
Keyword(s):  
Radial Velocity ◽  
Velocity Curve ◽  
Orbital Elements ◽  
Radial Velocity Curve

scholarly journals The GAPS Programme with HARPS-N at TNG

2018 ◽  
Vol 616 ◽  
pp. A155 ◽  
Author(s):  
A. F. Lanza ◽  
L. Malavolta ◽  
S. Benatti ◽  
S. Desidera ◽  
A. Bignamini ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Cross Correlation ◽  
Main Sequence ◽  
Activity Level ◽  
P Value ◽  
Main Sequence Stars ◽  
Stellar Spectrum ◽  
Stellar Activity ◽  
Binary Weighted ◽  
Low Activity

Aims. Stellar activity is the ultimate source of radial-velocity (hereinafter RV) noise in the search for Earth-mass planets orbiting late-type main-sequence stars. We analyse the performance of four different indicators and the chromospheric index log R′HK in detecting RV variations induced by stellar activity in 15 slowly rotating (υ sin i ≤ 5 km s−1), weakly active (log R′HK ≤ −4.95) solar-like stars observed with the high-resolution spectrograph High Accuracy Radial velocity Planet Searcher for the Northern hemisphere (HARPS-N). Methods. We consider indicators of the asymmetry of the cross-correlation function (CCF) between the stellar spectrum and the binary weighted line mask used to compute the RV, that is the bisector inverse span (BIS), ΔV, and a new indicator Vasy(mod) together with the full width at half maximum (FWHM) of the CCF. We present methods to evaluate the uncertainties of the CCF indicators and apply a kernel regression (KR) between the RV, the time, and each of the indicators to study their capability of reproducing the RV variations induced by stellar activity. Results. The considered indicators together with the KR prove to be useful to detect activity-induced RV variations in ~47 ± 18 percent of the stars over a two-year time span when a significance (two-sided p-value) threshold of one percent is adopted. In those cases, KR reduces the standard deviation of the RV time series by a factor of approximately two. The BIS, the FWHM, and the newly introduced Vasy(mod) are the best indicators, being useful in 27 ± 13, 13 ± 9, and 13 ± 9 percent of the cases, respectively. The relatively limited performances of the activity indicators are related to the very low activity level and υ sin i of the considered stars. For the application of our approach to sun-like stars, a spectral resolution allowing λ/Δλ ≥ 105 and highly stabilized spectrographs are recommended.

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