J/A+A/552/A114 Sun chromospheric CaII-HK emission (Shapiro+, 2013)
The place of the Sun among the Sun-like stars.
Shapiro A.I., Sch,utz W., Cessateur G., Rozanov E.
<Astron. Astrophys. 552, A114 (2013)>
=2013A&A...552A.114S 2013A&A...552A.114S
ADC_Keywords: Sun ; Models
Keywords: stars: activity - stars: solar-type - stars: variables: general -
Sun: activity - Sun: atmosphere
Abstract:
Monitoring of the photometric and chromospheric HK emission data
series of stars similar to the Sun in age and average activity level
showed that there is an empirical correlation between the average
stellar chromospheric activity level and the photometric variability.
In general, more active stars show larger photometric variability.
Interestingly, the measurements and reconstructions of the solar
irradiance show that the Sun is significantly less variable than
indicated by the empirical relationship.
We aim to identify possible reasons for the Sun to be currently
outside of this relationship.
We employed different scenarios of solar HK emission and irradiance
variability and compared them with available time series of Sun-like
stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 24 9354 Variability long-term VLT=0%, V11=0.00044mag,
no secular changes of the chromospheric activity
(upper-left panel in Fig. 3);
table2.dat 23 9354 Variability long-term VLT=0.044%, V11=0.00044mag,
strong changes of the chromospheric activity
(upper-right panel in Fig. 3);
table3.dat 23 9354 Variability long-term VLT=0.17%, V11=0.00044mag,
strong changes of the chromospheric activity
(middle-left panel in Fig. 3);
table4.dat 23 9354 Variability long-term VLT=0.17%, V11=0.00044mag,
no secular changes of the chromospheric activity
(middle-right panel in Fig. 3);
table5.dat 23 9354 Variability long-term VLT=0.5%, V11=0.00044mag,
strong changes of the chromospheric activity
(lower-left panel in Fig. 3);
table6.dat 23 9354 Variability long-term VLT=0.5%, V11=0.0002mag,
no secular changes of the chromospheric activity
(lower-right panel in Fig. 3).
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See also:
J/A+A/309/655 : Solar chromospheric activity (HeI 10830A) (Shcherbakov+, 1996)
Byte-by-byte Description of file: table?.dat
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Bytes Format Units Label Explanations
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1- 10 F10.7 [-] logR'HK Mean over last 9000 years chromospheric activity
14- 23 F10.7 [-] Var ? Variability Stromegren indices, log(rms(b+y)/2
24 A1 --- n_Var [i] i for -∞ (i.e. Var=0)
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Acknowledgements:
Alexander Shapiro, alexander.shapiro(at)pmodwrc.ch
(End) Patricia Vannier [CDS] 17-Apr-2013