J/A+A/540/A82 CaIIHK emission in stars with close-in planets (Krejcova+, 2012)
Evidence for enhanced chromospheric Ca II H and K emission in stars with
close-in extrasolar planets.
Krejcova T., Budaj J.
<Astron. Astrophys., 540, A82 (2012)>
=2012A&A...540A..82K 2012A&A...540A..82K
ADC_Keywords: Stars, double and multiple ; Planets ; Equivalent widths
Keywords: planets and satellites: general -
planets and satellites: magnetic fields - planet-star interactions -
stars: chromospheres - stars: magnetic field - planetary systems
Abstract:
The planet-star interaction is manifested in many ways. It has been
found that a close-in exoplanet causes small but measurable
variability in the cores of a few lines in the spectra of several
stars, which corresponds to the orbital period of the exoplanet. Stars
with and without exoplanets may have different properties.
The main goal of our study is to search for the influence that
exoplanets might have on atmospheres of their host stars. Unlike the
previous studies, we do not study changes in the spectrum of a host
star or differences between stars with and without exoplanets. We aim
to study a large number of stars with exoplanets and the current level
of their chromospheric activity and to look for a possible correlation
with the exoplanetary properties.
Description:
To analyse the chromospheric activity of stars, we exploited our
own and publicly available archival spectra, measured
the equivalent widths of the cores of Ca II H and K lines, and used
them to trace their activity. Subsequently, we searched for their
dependence on the orbital parameters and the mass of the exoplanet.
Stellar spectra used in our analysis originate from two different
sources. The main source is the publicly available Keck HIRES
spectrograph archive. These spectra have a typical resolution of up to
85000. We carefully selected only those spectra with the
signal-to-noise ratio high enough to measure the precise EQW of Ca II
K emission.
These data were accompanied by our own observations of several stars
(HD 179949, HD 212301, HD 149143, and Wasp-18) with a close-in
exoplanet. We obtained these data with the FEROS spectrograph mounted
on the 2.2m ESO/MPG telescope (night 18/19.9.2010).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 83 210 Parameters of exoplanetary systems
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See also:
J/MNRAS/414/108 : Calibrator of exoplanet-host stars (Beust+, 2011)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Object Planet name
14 A1 --- --- [/]
15- 24 A10 --- OName Other planet name
28- 34 F7.4 Mjup Mpsini Planet mass (Mp*sini)
37- 49 F13.8 d Porb Orbital period
53- 60 F8.6 AU a Planet distance to the star
62- 65 I4 K Teff Effective temperature of star
67- 73 F7.4 0.1nm EWCaIIK ?=- CaII K equivalent width
75- 80 F6.3 [-] logR'HK ?=- Activity index
82- 83 A2 --- Det [T RV] Detection method: transit (T)
or radial velocity (RV)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 18-Jun-2012