J/ApJ/457/L99 25yr CaII-HK observations of F-K nearby stars (Baliunas+, 1996)
Magnetic field and rotation in lower main-sequence stars: an empirical
time-dependent magnetic Bode's relation?
Baliunas S., Sokoloff D., Soon W.
<Astrophys. J., 457, L99-L102 (1996)>
=1996ApJ...457L..99B 1996ApJ...457L..99B
ADC_Keywords: Stars, nearby ; Stars, G-type ; Photometry, K-line
Keywords: Stars: Magnetic Fields; Stars: Rotation
Abstract:
We find a significant correlation between the magnetic and rotational
moments for a sample of 112 lower main-sequence stars. The rotational
moment is calculated from measurements of the rotation period in most
of the stars (not from the projected rotational velocity inferred from
Doppler broadening). The magnetic moment is computed from a database
of homogeneous measurements of the mean level of Ca II H and K
emission fluxes sampled for most of the stars over an interval of
25yr. The slope connecting the logarithm of the magnetic moment and
the logarithm of the rotational moment is about +0.5-0.6, with a
Pearson correlation coefficient of about +0.9. The scatter of points
from the mean relation has a component that is natural and caused by
decade-long surface variability.
Description:
At Mount Wilson Observatory, the Ca II H [396.8nm] and K [393.4nm]
emission fluxes have been observed in ∼100 stars on or near the lower
main sequence since 1966 (see Wilson, 1968ApJ...153..221W 1968ApJ...153..221W and
1978ApJ...226..379W 1978ApJ...226..379W).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 106 112 *Time-averaged CaII fluxes and rotation periods
for Wilson survey stars
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Note on table1.dat: The original table only contains the first four columns;
other columns were added by Eric Mamajek (Univ. of Rochester;
see the "Acknowledgements" section below).
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See also:
III/159 : Ca II H and K Measurements Made at MWO (Duncan+ 1991)
J/ApJS/211/24 : Rotation periods of Kepler MS stars (McQuillan+, 2014)
J/A+A/552/A114 : Sun chromospheric CaII-HK emission (Shapiro+, 2013)
J/A+A/552/A27 : Stellar activity and kinematics of FGK stars (Murgas+, 2013)
J/A+A/551/L8 : Chromospheric activity of field stars (Pace, 2013)
J/A+A/547/A106 : Li abundances in the FGK dwarfs (Mishenina+, 2012)
J/A+A/531/A8 : Activity indexes and velocities for 890 stars (Jenkins+, 2011)
J/AZh/88/1217 : Solar-like activity of low-mass stars (Kasova+, 2011)
J/ApJ/743/48 : Stellar rotation periods & X-ray luminosities (Wright+, 2011)
J/ApJ/725/875 : Chromospheric activity for CPS stars (Isaacson+, 2010)
J/A+A/520/A79 : FGK stars chromospheric activity (Martinez-Arnaiz+, 2010)
J/A+A/493/1099 : CaII HK emission in rapidly rotating stars (Schroeder+, 2009)
J/ApJ/687/1264 : Age estimation for solar-type dwarfs (Mamajek+, 2008)
J/A+A/483/903 : Mt Wilson index for main sequence F-K stars (Buccino+, 2008)
J/A+A/469/309 : Chromospheric activity in late-type stars (Cincunegui+, 2007)
J/AJ/133/2524 : Spectra of young nearby stars (White+, 2007)
J/ApJS/152/261 : Chromospheric Ca II emission in nearby stars (Wright+, 2004)
J/A+A/397/147 : Activity-rotation relationship in stars (Pizzolato+ 2003)
J/A+AS/146/103 : CaII H+K to CaII IRT echelle spectra (Montes+, 2000)
J/AJ/116/1922 : CaII H and K filter photometry III. (Anthony-Twarog+, 1998)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name HD name (or Sun)
12- 15 F4.2 mag B-V [0.4/1.6] B-V color index
17- 22 F6.3 [-] log<R'HK> [-5.5/-4.1] R'HK chromospheric activity (1)
24- 25 I2 d <Prot> [1/71] Measured rotation period unless flagged
26 A1 --- n_<Prot> [n] Rotation from CaII/Rossby relation (2)
28- 37 F10.6 deg RAdeg ? Tycho-2 right ascension (J2000) (3)
39- 48 F10.6 deg DEdeg ? Tycho-2 declination (J2000) (3)
50- 53 I4 --- TYC1 ? Tycho-2 name, field 1
55- 58 I4 --- TYC2 ? Tycho-2 name, field 2
60 I1 --- TYC3 ? Tycho-2 name, field 3
62- 67 I6 --- HIP ? HIP number
69- 86 A18 --- SpT MK Spectral Type (4)
88-106 A19 --- r_SpT Bibcode for Spectral Type (4)
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Note (1): Time-averaged Ca II flux.
Note (2):
n = Rotation periods are calculated using the CaII activity vs. Rossby number
relation (Noyes et al. 1984ApJ...279..763N 1984ApJ...279..763N).
Note (3): from Tycho-2 (Cat. I/259), for epoch 2000.0
Note (4): Preferentially selected from surveys by Keenan and Gray (and
collaborators). Both spectral type and bibcode were drawn from
Skiff's MK spectral type compilation (Cat. B/mk).
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Acknowledgements:
Eric E. Mamajek [Dept. of Physics & Astronomy, Univ. of Rochester]
(End) Emmanuelle Perret [CDS] 09-Jul-2015