J/A+A/515/A81 TYC 2627-638-1 BV(RI)c differential photometry (Olah+, 2010)
Young solar type active stars: the TYC 2627-638-1 system.
Olah K., Korhonen H., Vida K., Ilyin I., Dall T.H., Jarvinen S.P.,
Jurcsik J., Andersen M.I., Djupvik A.A., Pursimo T., Moor A., Datson J.,
Karjalainen R., Liimets T., Kubat J., Kawka A.
<Astron. Astrophys. 515, A81 (2010)>
=2010A&A...515A..81O 2010A&A...515A..81O
ADC_Keywords: Stars, double and multiple ; Stars, G-type ; Photometry, UBVRI ;
Photometry, Cousins
Keywords: stars: activity - stars: atmospheres - stars: late-type - starspots
Abstract:
We present BV(RI)c and JHKs photometry and low- and high-resolution
spectroscopy of the 11th mag G-type star TYC 2627-638-1. Our
investigation reveals that the target is separated into two young,
early-G-type main-sequence (or late pre-main-sequence) stars, which
are most probably bound and form a wide binary system. A substellar
body orbits the brighter component as implied by radial velocity
variations. The brighter component possibly also has a faint, later
type stellar companion. Both components of the wide binary have clear
emission cores in the CaII H&K lines and filled-in Halpha absorption,
indicating that both stars are chromospherically active. Our
photometric time series reveals clear but only a few hundredths of a
magnitude amplitude rotational modulation, which is most likely due to
cool starspots. Two distinct periods, near 3.5 and 3.7-days, are found
in the brightness variations. Photometry obtained separately of the
two components of the wide binary show that these periodicities belong
to the brighter star. The fainter component shows a much slower light
variation of about 0.3mag. amplitude. In addition, long-term changes
in the brightness of both stars are seen. The spectral energy
distribution shows a strong near-infrared excess in the fainter
component of the wide binary.
Description:
We present altogether 7100 B, V, Ic and 2391 Rc observations, all
interpolated to the time of the V-magnitude, obtained in 2006-2009
with the automated 60cm telescope (1) in Budapest and with the 1m
RCC telescope (2) in Piszkesteto mountain station of Konkoly
Observatory, with CCD cameras and BV(RI)c filters. The data are given
as delta magnitudes with respect to the main comparison star C0
(V=11.841, B-V=0.582, V-Rc=0.315, V-Ic=0.666, Jurcsik et al., 2008,
Cat. <J/MNRAS/391/164). The data are transformed to the international
system through Landolt standard sequences.
Objects:
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RA (2000) DE Designation(s)
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18 20 05.4 +31 57 44 TYC 2627-638-1 = 2MASS J18200537+3157444
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
ab-bvi.dat 40 4906 BVIc magnitudes of TYC 2627-638-1 (A+B components
together), with the 60cm telescope
ab-r.dat 35 197 Rc magnitudes of TYC 2627-638-1 (A+B components
together), with the 60cm telescope
ab-bvri.dat 40 2194 BV(RI)c magnitudes of TYC 2627-638-1 (A+B components
together), with the 1m telescope
a-bvri.dat 40 300 BV(RI)c magnitudes of TYC 2627-638-1A component
separately, with the 1m telescope
b-bvri.dat 40 325 BV(RI)c magnitudes of TYC 2627-638-1B component
separately, with the 1m telescope
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
J/MNRAS/391/164 : MW Lyr BV(RI)c light curves (Jurcsik+, 2008)
Byte-by-byte Description of file: *.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian date
14- 19 F6.3 mag DBmag ? Differential Johnson B magnitude
21- 26 F6.3 mag DVmag ? Differential Johnson B magnitude
28- 33 F6.3 mag DRcmag ? Differential Cousins R magnitude
35- 40 F6.3 mag DIcmag ? Differential Cousins I magnitude
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Acknowledgements:
Katalin Olah, olah(at)konkoly.hu
(End) Patricia Vannier [CDS] 10-Apr-2010