J/A+A/410/671 X-ray emission in cool main sequence stars (Messina+, 2003)
Dependence of coronal X-ray emission on spot-induced brightness variations in
cool main sequence stars.
Messina S., Pizzolato N., Guinan E.F., Rodon M.
<Astron. Astrophys. 410, 671 (2003)>
=2003A&A...410..671M 2003A&A...410..671M
ADC_Keywords: Stars, late-type ; X-ray sources ; Magnetic fields
Keywords: stars: activity - stars: late-type - stars: magnetic fields -
stars: starspots - X-rays: stars
Abstract:
The maximum amplitude Amax of spot-induced brightness variations
from long-term V-band photometry and the ratio LX/Lbol between
X-ray and bolometric luminosities are suitable indicators of the level
of magnetic activity in the photosphere and in the corona of late-type
stars, respectively. By using these activity indicators we investigate
the dependence of coronal X-ray emission on the level of photospheric
starspot activity in a homogeneous sample of low mass main-sequence
field and cluster stars of different ages (IC 2602, IC 4665, IC 2391,
α Per, Pleiades and Hyades).
Objects:
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RA (2000) DE Designation(s)
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10 44.3 -64 20 IC 2602
17 46.3 +05 43 IC 4665
08 40.2 -53 04 IC 2391
03 22.0 +48 37 alpha Per
03 47.0 +24 07 Pleiades
04 26.9 +15 52 Hyades
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 79 264 Photometry
table2.dat 50 228 X-ray data
refs.dat 161 93 References
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See also:
IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)
V/80 : Low-Mass Stars Membership in Alpha Per Cluster (Prosser 1992)
J/ApJS/91/625 : ROSAT survey of the Pleaides (Stauffer+ 1994)
J/A+A/341/751 : ROSAT HRI observations of the Pleiades (Micela+ 1999)
J/AJ/105/1441 : IC 4665 (Prosser 1993)
J/ApJS/85/315 : F, G and K dwarf stars of the Pleiades (Soderblom+ 1993)
J/ApJS/91/625 : ROSAT survey of the Pleaides (Stauffer+ 1994)
J/A+AS/115/41 : UBV(RI) photometry of cool stars (Cutispoto+, 1996)
J/A+AS/120/127 : UBVRI photometry of 7 dwarfs in Alpha Per (Bouvier 1996)
J/A+A/335/183 : Pleiades low-mass stars rotational velocities (Queloz+ 1998)
J/A+AS/127/207 : UBV(RI)c photometry of active stars. VII. (Cutispoto 1998)
J/A+A/350/513 : V368 Cep UBVRI time series (Kahanpaa+, 1999)
J/A+AS/138/87 : UBVRI photometry of EUV stellar sources (Cutispoto+ 1999)
J/A+AS/140/29 : Photometric monitoring of late-type stars (Strassmeier+ 1999)
J/A+A/364/205 : UBVy photometry of cool stars (Cutispoto+, 2000)
J/A+AS/142/275 : Stellar-activity of late-type stars (Strassmeier+ 2000)
J/A+A/367/910 : UBV(RI)c photometry of active stars. IX (Cutispoto+, 2001)
J/A+A/393/225 : Starspot cycles of six young solar analogues (Messina+, 2002)
J/A+A/394/505 : UBV photometry of LQ Hya (Berdyugina+, 2002)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Cluster Cluster to which the star belongs
10 A1 --- n_Name [*] *: Stars for which the unpublished
Villanova photometry was used
12- 21 A10 --- Name Name in the catalogue
23- 31 A9 --- Oname Other name as variable star
33- 37 F5.2 mag Vmax Brightest V-band magnitude
40- 44 F5.2 mag B-V ?=99.00 B-V colour
46- 51 F6.3 d Per Rotational period
53- 57 F5.3 mag Amax Maximum V-band light curve amplitude
60- 62 A3 --- r_Per Reference for rotational period,
in refs.dat file
65- 67 A3 --- r_Amax Reference for light curve amplitude,
in refs.dat file
70- 71 I2 --- LC Number of light curve
74- 79 A6 --- Flag Star used to define the upper envelope (1)
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Note (1): Flags:
FS_fit means F-type star in the slow rotational regime
GS_fit means G-type star in the slow rotational regime
KS_fit means K-type star in the slow rotational regime
GF_fit means G-type star in the fast rotational regime
KF_fit means K-type star in the fast rotational regime
M0_fit means M-type stars in upper envelope 2
M1_fit means M-type stars in upper envelope 1
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Cluster Cluster to which the star belongs
12- 21 A10 --- Name Name in the catalogue
24- 29 F6.3 [10-7W] logLX X-ray luminosity
33- 38 F6.3 --- logLX/Lbol X-to-bolometric luminosities ratio
42- 46 F5.3 --- e_logLX/Lbol Uncertainty on logLX/Lbol
48- 50 A3 --- r_logLX [a-h ] References for logLX, in refs.dat file
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Ref Reference number
5- 13 A9 --- Cluster Cluster to which the star belongs
15- 33 A19 --- BibCode BibCode
35- 61 A27 --- Aut Author's name
62-161 A100 --- Com Comments
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Acknowledgements: Sergio Messina
(End) Patricia Bauer [CDS] 16-Oct-2003