J/A+AS/121/369 UBVRI observations of active stars (Cutispoto, 1997)
Long-term monitoring of active stars.
VI. UBV(RI)c observations collected in Sep-Oct 1990
Cutispoto G.
<Astron. Astrophys. Suppl. Ser. 121, 369 (1997)>
=1997A&AS..121..369C 1997A&AS..121..369C (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Photometry, UBVRI ; Photometry, Cousins
Keywords: stars: activity - stars: late-type - stars: variables -
techniques: photometric
Abstract:
In the framework of an extensive program focusing on the global
properties and evolution of active stars, high-precision UBV(RI)c
photometry of 9 selected stars, collected at the European Southern
Observatory over the intervals 7-17 September and
30 September - 10 October 1990, is presented. Significant evolution of
the light curves, period variations and evidence for long-term
variability of the global degree of spottedness are found. Some of the
spectral classifications are discussed. These observations contribute
to the establishment of a time-extended photometric database which can
give important clues on topics such as the stability of the spotted
areas, differential rotation, solar-like cycles and the correlation
between inhomogeneities at different atmospheric levels.
For a description of the UBV and (RI)c photometric systems, see e.g.
General Catalog of Photometric Data GCPD/01 and GCPD/54
Objects:
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RA (2000) DE Designation(s)
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00 53 04.8 -74 39 07 CF Tuc = HD 5303
01 22 19.0 -56 43 52 BC Phe = HD 8435
02 34 22.2 -43 47 33 CC Eri = HD 16157
04 58 18.2 -75 16 36 YY Men = HD 32918
17 17 25.6 -66 56 56 V824 Ara = HD 155555
18 53 05.6 -50 10 45 PZ Tel = HD 174429
20 45 08.3 -31 20 09 AU Mic = HD 197481
22 38 43.9 -20 37 12 FK Aqr = HD 214479
23 00 27.6 -33 44 34 TZ PsA = HD 217344
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 63 9 Maximum luminosity and corresponding colors
for the program stars
table4.dat 36 18 V magnitude and colors for the c and ck stars
derived via standard stars
table.dat 57 108 UBVRI photometry of program stars
tables.tex 80 62 LaTeX version of tables 3 and 4
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See also:
J/A+AS/119/281 : UBV(RI)c photometry of active stars. V. (Cutispoto, 1996)
J/A+AS/127/207 : UBV(RI)c photometry of active stars. VII. (Cutispoto 1998)
J/A+AS/131/321 : UBV(RI)c photometry of active stars. VIII. (Cutispoto 1998)
J/A+A/367/910 : UBV(RI)c photometry of active stars. IX. (Cutispoto+, 2001)
J/A+A/400/659 : UBV(RI)c photometry of active stars. X (Cutispoto+, 2003)
Table 1: Comparison (c) and check (ck) stars used for each program star
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Program Star Comparison star Check star
(v) (c) (ck)
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HD 5303 = CF Tuc HD 5210 HD 6446
HD 8435 = BC Phe HD 8617 HD 9896
HD 16157 = CC Eri HD 16371 SAO 215945
HD 32918 = YY Men HD 33763 HD 33747
HD 155555 = V824 Ara HD 156427 HD 154775
HD 174429 = PZ Tel HD 173560 HD 176557
HD 197481 = AU Mic HD 197237 HD 197339
HD 214479 = FK Aqr HD 214046 HD 214380
HD 217344 = TZ PsA HD 217108 HD 217935
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Table2: Mean atmospheric extinction coefficients for La Silla site,
obtained over the period 7 Sep - 10 Oct 1990
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U B V R I
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Mag/airmass .460 .217 .125 .087 .041
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Variable Name (v)
11- 14 F4.2 mag Vmax V-band maximum luminosity
16- 19 F4.2 mag U-B U-B color index at maximum luminosity
21- 24 F4.2 mag B-V B-V color index at maximum luminosity
26- 29 F4.2 mag V-Rc V-Rc color index at maximum luminosity
31- 34 F4.2 mag V-Ic V-Ic color index at maximum luminosity
36- 37 I2 mmag Vv-c Standard deviation for the v-c V-band
differential magnitudes
39- 40 I2 mmag Vck-c Standard deviation for the ck-c V-band
differential magnitudes
42- 43 I2 --- o_Vmax Number of nights
46- 63 A18 --- Sp Inferred spectral type
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- HD c or ck HD number
12- 15 F4.2 mag Vmag V-band magnitude
17- 20 F4.2 mag U-B U-B color index
21 A1 --- u_U-B Uncertainty flag on U-B (1)
23- 26 F4.2 mag B-V B-V color index
28- 31 F4.2 mag V-Rc V-Rc color index
33- 36 F4.2 mag V-Ic V-Ic color index
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Note (1): Errors are of the order of 0.01 magnitudes.
The symbol ":" denotes errors of the order of 0.02 magnitudes
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Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Star name
10- 21 F12.4 d HJD Heliocentric Julian day
23- 27 F5.4 --- Phase [0/1[ Phase (1)
29- 33 F5.3 mag Vmag V magnitude
35- 39 F5.3 mag U-B ? U-B color index
41- 45 F5.3 mag B-V B-V color index
47- 51 F5.3 mag V-R V-R color index
53- 57 F5.3 mag V-I V-I color index
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Note (1): Phases are computed using the ephemeride:
CF Tuc : HJD=2444554.992 + 2.797672 x E
BC Phe : HJD=2447869.0 + 0.649 x E
CC Eri : HJD=2447129.529 + 1.56145 x E
YY Men : HJD=2444155.64 + 9.5476 x E
V824 Ara : HJD=2445803.07 + 1.681652 x E
PZ Tel : HJD=2448141.5 + 0.9447 x E
AU Mic : HJD=2441054.0 + 4.865 x E
FK Aqr : HJD=2448141.0 + 4.252 x E
TZ PsA : HJD=2448141.54 + 1.648 x E
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Acknowledgements: Giuseppe Cutispoto
References:
Rodono & Cutispoto, Paper I 1992A&AS...95...55R 1992A&AS...95...55R
Cutispoto Paper II 1992A&AS...95..397C 1992A&AS...95..397C
Cutispoto Paper III 1993A&AS..102..655C 1993A&AS..102..655C
Cutispoto Paper IV 1995A&AS..111..507C 1995A&AS..111..507C
Cutispoto Paper V 1996A&AS..119..281C 1996A&AS..119..281C, Cat. J/A+AS/119/281
Cutispoto Paper VII 1998A&AS..127..207C 1998A&AS..127..207C, Cat. J/A+AS/127/207
Cutispoto Paper VIII 1998A&AS..131..321C 1998A&AS..131..321C, Cat. J/A+AS/131/321
Cutispoto et al., Paper IX 2001A&A...367..910C 2001A&A...367..910C, Cat. J/A+A/367/910
Cutispoto et al., Paper X 2003A&A...400..659C 2003A&A...400..659C, Cat. J/A+A/400/659
(End) Patricia Bauer [CDS] 24-Jul-1996