J/A+AS/115/41 UBV(RI) photometry of cool stars (Cutispoto+, 1996)
Photometric and spectroscopic studies of cool stars discovered in EXOSAT
X-ray images. III. Photometric properties
Cutispoto G., Tagliaferri G., Pallavicini R., Pasquini L., Rodono M.
<Astron. Astrophys. Suppl. Ser. 115, 41 (1996)>
=1996A&AS..115...41C 1996A&AS..115...41C (SIMBAD/NED BibCode)
ADC_Keywords: Photometry, UBVRI ; Stars, late-type ; X-ray sources
Keywords: stars: activity - stars: late-type - stars: variables - X-ray: stars
Description:
We present high-precision UBV(RI)c photometry for a sample of active
stars detected serendipitously by the EXOSAT satellite. Fourteen
objects, out of 47 likely optical counterparts, turned out to be
clearly variable, with periods in the range 1-8 days, including a
newly discovered eclipsing binary. For most of them the optical
variability is consistent with the presence of photospheric cool
spots. We have used our multicolour photometry to estimate spectral
classifications and distances. The derived distances indicate that
some of the observed stars are previously unidentified nearby
(d≤25pc) M dwarfs. When combined with the results of high resolution
spectroscopy, our photometric observations allow us to investigate the
stellar content of the selected X-ray sample. Young stars and RS
CVn-type binaries appear to constitute a large fraction of the
selected sample. For a description of the UBV and (RI)c photometric
systems, see e.g.
http://obswww.unige.ch/gcpd/ph01.html and
http://obswww.unige.ch/gcpd/ph54.html.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2 58 101 Photometric data for the observed stars
table3 67 54 Photometric data
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See also:
J/A+A/364/205 : UBVy photometry of cool stars. (Cutispoto+, 2000)
Byte-by-byte Description of file: table2
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Bytes Format Units Label Explanations
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2- 3 I2 --- Id Identification number
5- 21 A17 --- Name EXOSAT name (Catalogue VI/43)
23- 25 A3 --- ObsSeason Code for the observing season (1)
26 A1 --- n_ObsSeason When "o": data from Paper I:
Cutispoto G. et al 1991
28- 32 F5.2 mag Vmax V magnitude at maximum luminosity
34- 37 F4.2 mag U-B ? U-B color index
39- 42 F4.2 mag B-V B-V color index
44- 47 F4.2 mag V-Rc V-Rc color index (Cousins)
49- 52 F4.2 mag V-Ic V-Ic color index (Cousins)
54 A1 --- Qual Quality of the data
57 A1 --- Var Variability flag
58 A1 --- n_Var [?] Uncertainty on variability flag
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Note (1): The code is composed by the initial of the month followed
by the two last numbers of the year.
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Byte-by-byte Description of file: table3
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Bytes Format Units Label Explanations
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2- 6 A5 --- Id Identification number
8- 24 A17 --- EXOSAT EXOSAT name
25- 34 A10 --- Other Other catalogue number
36- 46 A11 --- Sp Spectral type
48- 51 I4 pc Dist ? Distance
52 A1 --- n_Dist [?] Uncertainty on distance
54 A1 --- Var Variability flag
56- 60 F5.3 d Period ? Period of variability
61 A1 --- n_Period [?] Uncertainty on period of variability
63 A1 --- l_DeltaV [>] Limit flag on amplitude in V-band
64- 67 F4.2 mag DeltaV ? Amplitude in the V-band
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References:
Cutispoto et al., Paper I =1991A&AS...87..233C 1991A&AS...87..233C
Tagliaferri et al., Paper II =1994A&A...285..272T 1994A&A...285..272T
Cutispoto et al., Paper IV =2000A&A...364..205C 2000A&A...364..205C, Cat. J/A+A/364/205
(End) Simona Mei [CDS] 25-Sep-1995