J/A+A/362/223 1984-1998 BV photometry of V815 Her (Jetsu+, 2000)
Time series analysis of V815 Herculis photometry between 1984 and 1998
Jetsu L., Hackman T., Hall D.S., Henry G.W., Kokko M., You J.
<Astron. Astrophys. 362, 223 (2000)>
=2000A&A...362..223J 2000A&A...362..223J
ADC_Keywords: Stars, variable ; Photometry, UBV
Keywords: stars: individual: V815 Her - stars: variables: general -
stars: activity - techniques: photometric
Abstract:
As a case study of the solar-stellar connection, we have analysed a
prolonged time series of BV photometry of the chromospherically active
binary V815 Her. The surface differential rotation in the rapidly
rotating G5V primary caused changes of 4.6% in the seasonal
photometric rotation periods. This would imply a differential rotation
coefficient of k=0.184, if the rotation of the starspots follow the
solar law of differential rotation and the activity is confined within
the same latitudinal range as in the Sun, having k=0.189 and the
spectral type G2V. Our analysis of the primary and secondary minima of
the seasonal light curves indicated that the regions of stronger
activity have concentrated on one active longitude, which has
maintained a constant rotation period of 1.79244d for about 14 years.
No regular activity cycle was detected in the mean brightness changes
of V815 Her.
Objects:
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RA (2000) DE Designation(s)
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18 08 16.0 +29 41 28 V815 Her = HD 166181
18 07 52.0 +29 49 05 HD 166093
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 29 1458 V and B V815 Her differential magnitudes
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See also:
J/A+A/350/513 : V368 Cep UBVRI time series (Kahanpaa+, 1999)
J/A+AS/139/513 : 1975-1995 V1794 Cyg UBVRI photometry (Jetsu+, 1999)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- SET Subset number ( a total of 98 subsets)
4- 15 F12.4 d HJD Heliocentric Julian date
17- 22 F6.3 mag Bmag ?=99.999 V815 Her minus HD 166093 magnitude
difference in the standard Johnson B system
24- 29 F6.3 mag Vmag ?=99.999 V815 Her minus HD 166093 magnitude
difference in the standard Johnson V system
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Acknowledgements: Lauri Jetsu
(End) Patricia Bauer [CDS] 24-Oct-2000