J/A+A/596/A76 Hα-activity in the SARG binary survey (Sissa+, 2016)
Hα-activity and ages for stars in the SARG survey.
Sissa E., Gratton R., Desidera S., Martinez Fiorenzano A.F.,
Bonfanti A., Carolo E., Vassallo D., Claudi R.U., Endl M., Cosentino R.
<Astron. Astrophys. 596, A76 (2016)>
=2016A&A...596A..76S 2016A&A...596A..76S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Radial velocities ; Spectroscopy
Keywords: : binaries: visual - stars: activity - techniques: radial velocities -
techniques: spectroscopic
Abstract:
Stellar activity influences radial velocity (RV) measurements and can
also mimic the presence of orbiting planets. As part of the search for
planets around the components of wide binaries performed with the SARG
High Resolution Spectrograph at the TNG, it was discovered that
HD 200466A shows strong variation in RV that is well correlated with
the activity index based on Hα. We used SARG to study the
Hα line variations in each component of the binaries and a few
bright stars to test the capability of the Hα index of revealing
the rotation period or activity cycle. We also analysed the relations
between the average activity level and other physical properties of
the stars. We finally tried to reveal signals in the RVs that are due
to the activity. At least in some cases the variation in the observed
RVs is due to the stellar activity. We confirm that Hα can be
used as an activity indicator for solar-type stars and as an age
indicator for stars younger than 1.5Gyr.
Description:
The SARG survey was the first planet research program entirely
dedicated to binary systems in nearly equal-mass visual binaries using
high-precision radial velocities. We study the activity of these stars
with a Hα-based index. All the Hα time serie of the stars
of the SARG survey and of six bright stars, plus a few RVs reference
stars are presented. In addition all the stellar parameter used and
the final mean activity are presented.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 84 104 Stellar parameters and SARG data
(sum of tables 1 and 2 of the paper)
table5.dat 40 3580 Hα time series
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Star name
14- 18 F5.3 mag Vmag V apparent magnitude
20- 23 F4.2 mag B-V B-V color index
25- 29 F5.2 [-] logRHK logR_HK activity index
31 A1 --- n_logRHK [DXU] Note on logRHK (1)
33- 36 F4.1 km/s Vsini Projected velocity
38- 41 I4 K T Temperature
43- 45 I3 --- Nobs Number of observations
47- 55 F9.4 d JD0 First observation (JD-2450000)
57- 65 F9.4 d JDf Last observation (JD-2450000)
67- 71 F5.3 --- <Ha> Average value of Hα index
73- 78 F6.3 --- DHa Hα excess
80- 84 F5.3 --- e_<Ha> Standard deviation of Hα index
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Note (1): Note as follows:
D = RHK from direct measurement
X = RHK from X-ray luminosity
U = upper limits for RHK, from X-ray luminosity
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Star name
14- 22 F9.4 d JD Julian date (JD-2450000)
24- 30 F7.5 --- Ha ?=0 Hα index
32- 38 F7.5 --- e_Ha ?=0 Hα index error
40 I1 --- Note [0/1] Note (1)
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Note (1): Note as follows:
0 = not used value
1 = used value
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Acknowledgements:
Elena Sissa, elena.sissa(at)oapd.inaf.it
(End) Patricia Vannier [CDS] 14-Sep-2016