J/A+A/592/A117 HU Vir radial velocities and VI light curves (Harutyunyan+, 2016)
Anti-solar differential rotation on the active sub-giant HU Virginis.
Harutyunyan G., Strassmeier K.G., Kuenstler A., Carroll T.A., Weber M.
<Astron. Astrophys. 592, A117 (2016)>
=2016A&A...592A.117H 2016A&A...592A.117H (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Photometry ; Radial velocities
Keywords: stars: activity - starspots - stars: imaging - stars: late-type -
stars: individual: HU Vir
Abstract:
We investigate the differential surface rotation on the primary star
of the RS CVn binary HU Vir by tracking its starspot distribution as a
function of time. We also recompute and update the values for several
system parameters of the triple system HU Vir (close and wide orbits).
Spectroscopic observations were carried out with the STELLA echelle
spectrograph (SES) at the robotic 1.2-m STELLA-I telescope at the
Observatorio del Teide in Tenerife, Spain. A time series of 118
echelle spectra was taken in the period between Feb 17 to Jun 26,
2013. Nine consecutive Doppler images were reconstructed from these
data, using our line-profile inversion code iMap. An image
cross-correlation method was applied to derive the surface
differential-rotation law for HU Vir. New orbital elements for the
close and the wide orbits were computed using our new STELLA RVs
combined with the RV data available in the literature.
Photometric observations were performed with the Amadeus Automatic
Photoelectric Telescope (APT) at Fairborn Observatory in southern
Arizona starting in 1996, providing contemporaneous Johnson-Cousins V
and I data for approximately 20 years. This data was used to determine
the stellar rotation period and the active longitudes.
Description:
We present two tables with the new STELLA radial velocity data set and
the APT Johnson-Cousins V and I photometric data set for HU Virginis.
RVs from STELLA-SES spectra were derived from an order-by-order cross
correlation with a synthetic template spectrum and then averaged. The
photometric measurements were always made differentially with respect
to HD 106270 and HD 106332 as a comparison and check star,
respectively.
Objects:
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RA (2000) DE Designation(s)
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12 13 20.7 -09 04 47 HU Vir = HD 106225
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
rv.dat 30 118 STELLA-SES radial velocities of HU Virginis
phot.dat 48 2816 Johnson-Cousins V and I photometry from APT
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See also:
J/A+AS/137/369 : 10 active binary radial velocities (Fekel+, 1999)
Byte-by-byte Description of file: rv.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD Heliocentric Julian Date
16- 22 F7.3 km/s RV Radial velocity
26- 30 F5.3 km/s e_RV Internal error of the RV
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Byte-by-byte Description of file: phot.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD Heliocentric Julian Date
16- 21 F6.4 mag dVmag Differential V magnitude (HU Vir - HD 106270)
24- 29 F6.4 mag e_dVmag Error of the dVmag
33- 39 F7.4 mag dImag ?=99.0000 Differential I magnitude
(HU Vir - HD 106270)
42- 48 F7.4 mag e_dImag ?=99.0000 Error of the dImag
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Acknowledgements:
Gohar Harutyunyan, gharutyunyan(at)aip.de
(End) Gohar Harutyunyan [AIP], Patricia Vannier [CDS] 06-Jul-2016