J/A+A/310/143 Variability of classical T Tauri stars (Fernandez+, 1996)
Variability of classical T Tauri stars. Its relation to the accretion process
Fernandez M., Eiroa C.
<Astron. Astrophys. 310, 143 (1996)>
=1996A&A...310..143F 1996A&A...310..143F (SIMBAD/NED BibCode)
ADC_Keywords: Photometry, UBVRI
Keywords: stars: formation - stars: pre-main sequence - accretion disks
stars spots
Description:
We present the analysis of a UBV(RI)c photometric monitoring program
carried out from July 1988 to August 1992 on a sample of 13 classical
T Tauri stars and 2 suspected classical T Tauri stars. We detected
optical irregular variability with an amplitude larger than 0.1mag in
the V band in 8 stars. For 5 of them most of the variability can be
attributed to hot spots, for one, to cool spots and for two of them,
there is no clear mechanism; nevertheless, other phenomena must
explain the short term (hours - days) and long term (years)
variations superimposed. For some objects an anomalous behaviour at
the shorter wavelengths (U band) is detected. From the comparison
between the amplitude of the optical variability due to hot spots and
the equivalent width of the Halpha emission a correlation between them
is suggested. Assuming that the Halpha emission is related to the
accretion process, this correlation supports the idea that we are
observing the hot spots where the material from the accretion disks
falls onto the star.
For a description of the (RI)c photometric system, see e.g.
GCPD/54
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tables 79 35 Average values of the photometric observations
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Byte-by-byte Description of files: tables
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Star name
17- 28 A12 --- Date Observing run (1)
33- 37 F5.2 mag Vmag V band
45- 48 F4.2 mag B-V (B-V) colour index
56- 59 F4.2 mag U-B []? (U-B) colour index
66- 69 F4.2 mag V-R []? (V-R) colour index
76- 79 F4.2 mag V-I []? (V-I) colour index
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Note (1): R and J denote the Romeo and Juliet photometers at the JKT telescope,
respectively.
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Courtesy: M. Fernandez
(End) Patricia Bauer [CDS] 08-Feb-1996