J/A+A/493/1099 CaII HK emission in rapidly rotating stars (Schroeder+, 2009)
CaII HK emission in rapidly rotating stars. Evidence of an onset of the
solar-type dynamo.
Schroeder C., Reiners A., Schmitt J.H.M.M.
<Astron. Astrophys. 493, 1099 (2009)>
=2009A&A...493.1099S 2009A&A...493.1099S
ADC_Keywords: Stars, nearby ; Stars, atmospheres ; Rotational velocities
Keywords: stars: activity - stars: chromospheres - stars: rotation
Abstract:
We present measurements of chromospheric CaII H&K activity for 481
solar-like stars. To determine the activity we used the Mount Wilson
method and a newly developed method which allows to also measure CaII
H&K emission features in very rapidly rotating stars. The new
technique determines the activity by comparing the line shapes from
known inactive slowly rotating template stars that have been
artificially broadened to spectra of rapid rotators. We have analyzed
solar-like stars ranging from T_eff=5000 to 7800K with rotational
velocities up to 190km/s in our sample of FOCES and FEROS spectra. The
effects of the rotational broadening on the two methods have been
quantified. Our method has proven to produce consistent results where
S-Index values are available and offers the possibility to measure the
chromospheric activity at the onset of the solar-like dynamo.
Description:
The basic data and chromosperic activity measurements for 480 stars.
Given are the S-index and log R(hk) measured with the Mount-Wilson
method and with the new template method.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 58 480 Basic data and the results of the activity
measurements of all 480 stars
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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- 6 I6 --- HD HD number (Cat. III/135)
8- 11 F4.2 mag B-V B-V color index
13 I1 --- T ?=- Id of the template star
15- 19 F5.1 km/s vsini Rotational velocity
21- 24 I4 K Teff ?=- Effective temperature
26- 29 F4.2 [cm/s2] logg ?=- Surface gravity
31- 32 A2 --- Class Evolutionary state (main sequence or giant)
34- 38 F5.3 --- S(cl) Classical Mount-Wilson S-index
40- 45 F6.3 --- logR(hk)cl ?=- Classical Mount-Wilson log R(hk)
47- 51 F5.3 --- S(t) ?=- Template S-index
53- 58 F6.3 --- logR(hk)t ?=- Template log R(hk)
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Acknowledgements:
Christian Schroeder, stdh321(at)hs.uni-hamburg.de
(End) C. Schroeder [Hamburger Sternwarte], P. Vannier [CDS] 02-Sep-2008