J/A+A/334/863 II Peg radial velocities (Berdyugina+ 1998)
The active RS Canum Venaticorum binary II Pegasi.
I. Stellar and orbital parameters.
Berdyugina S.V., Jankov S., Ilyin I., Tuominen I., Fekel F.C.
<Astron. Astrophys. 334, 863 (1998)>
=1998A&A...334..863B 1998A&A...334..863B (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, spectroscopic ; Radial velocities
Keywords: stars: binaries: spectroscopic - stars: fundamental parameters -
stars: abundances - stars: activity - stars: individual: II Peg
Abstract:
A detailed model atmosphere analysis of high-resolution and high S/N
CCD spectra of IIPeg has yielded for the first time a self-consistent
set of fundamental parameters of the primary component: Teff=4600K,
logg=3.2, [M/H]=-0.4, ξt=2.0km/s. In addition, 121 new high
quality radial velocity measurements allowed us to determine improved
orbital parameters, resulting in a new orbital ephemeris of
Tconj=2449582.9268+6.724333E. The position of the primary of II Peg
in the HR diagram with the new parameters corresponds to a K2 IV star
with mass ≃0.8M☉. The evolved character of the star is
confirmed by the C/N ratio, which is reduced significantly relative to
the solar value. The unspotted V magnitude of the star of 6.9mag is
estimated from the observed variations of the TiO bands and
quasi-simultaneous photometry. The blend of LiI 6707Å is suspected
to vary in equivalent width due to spot modulation. The lithium
abundance for the unspotted star, Li/H=1.0±0.1, is found to be
consistent with other post-main sequence chromospherically active
stars. Combining all parameters, the radius R≃3.4R☉ and the
inclination i≃60° of the primary are estimated with the
assumption that its rotational axis is perpendicular to the orbital
plane. The secondary is probably a M0-M3 V star with a mass of about
0.4M☉.
Objects:
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RA (2000) DE Designation(s)
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23 55 01.8 +28 37 59 II Peg = HD 224085
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 20 157 Radial velocity data
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 11 F11.3 d HJD Heliocentric Julian date
13- 17 F5.1 km/s RV Radial velocity
19 I1 --- r_RV [1/9] Reference for radial velocity (1)
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Note (1): 1: Sanford (1921ApJ....53..201S 1921ApJ....53..201S)
2: Halliday (1952JRASC..46..103H 1952JRASC..46..103H)
3: Heard (1956PDDO....2..105H 1956PDDO....2..105H)
4: Rucinski (1977PASP...89..280R 1977PASP...89..280R)
5: Vogt (1981ApJ...247..975V 1981ApJ...247..975V)
6: SOFIN echelle spectrograph (Nordic Optical Telescope,
Roque de los Muchocohs Observatory
7: Crimea Astrophysical Observatory
8: McDonald Observatory
9: Kitt Peak National Observatory
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History: Prepared via OCR at CDS.
(End) Patricia Bauer [CDS] 19-May-1998