J/A+A/670/A24 Photometric and spectroscopic granulation signals (Sulis+, 2023)
Connecting photometric and spectroscopic granulation signals with
CHEOPS and ESPRESSO.
Sulis S., Lendl M., Cegla H., Rodriguez Diaz L.F., Bigot L., Van Grootel V.,
Bekkelien A., Collier Cameron A., Maxted P.F.L., Simon A.E., Lovis C.,
Scandariato G., Bruno G., Nardiello D., Bonfanti A., Fridlund M.,
Persson C.M., Salmon S., Sousa S.G., Wilson T.G., Krenn A., Hoyer S.,
Santerne A., Ehrenreich D., Alibert Y., Alonso R., Anglada G., Barczy T.,
Barrado y Navascues D., Barros S.C.C., Baumjohann W., Beck M., Beck T.,
Benz W., Billot N., Bonfils X., Borsato L., Brandeker A., Broeg C.,
Cabrera J., Charnoz S., Corral van Damme C., Csizmadia Sz., Davies M.B.,
Deleuil M., Deline A., Delrez L., Demangeon O.D.S., Demory B.-O.,
Erikson A., Fortier A., Fossati L., Gandolfi D., Gillon M., Guedel M.,
Heng K., Isaak K.G., Kiss L.L., Laskar J., Lecavelier des Etangs A.,
Magrin D., Munari M., Nascimbeni V., Olofsson G., Ottensamer R., Pagano I.,
Palle E., Peter G., Piotto G., Pollacco D., Queloz D., Ragazzoni R.,
Rando N., Rauer H., Ribas I., Rieder M., Santos N.C., Segransan D.,
Smith A.M.S., Steinberger M., Steller M., Szabo Gy.M., Thomas N., Udry S.,
Walton N.A., Wolter D.
<Astron. Astrophys. 670, A24 (2023)>
=2023A&A...670A..24S 2023A&A...670A..24S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, dwarfs ; Stars, masses ; Effective temperatures ;
Photometry ; Optical
Keywords: methods: data analysis - Sun: granulation - stars: atmospheres -
techniques: photometric - techniques: radial velocities
Abstract:
Stellar granulation generates fluctuations in photometric and
spectroscopic data whose properties depend on the stellar type,
composition and evolutionary state. Characterizing granulation is key
for understanding stellar atmospheres and detecting planets.
We aim at detecting the signatures of stellar granulation, linking
spectroscopic and photometric signatures of convection for
main-sequence stars, and testing predictions from 3D hydrodynamic
models. For the first time, we observed two bright stars (Teff=5833K
and 6205K) with high-precision observations taken simultaneously with
CHEOPS and ESPRESSO. We analyzed the properties of the stellar
granulation signal in each individual data set. We compared them to
Kepler observations and 3D hydrodynamic models. While isolating the
granulation-induced changes by attenuating/filtering the p-mode
oscillation signals, we studied the relationship between photometric
and spectroscopic observables. The signature of stellar granulation is
detected and precisely characterized for the hotter F star in the
CHEOPS and ESPRESSO observations. For the cooler G star, we obtain a
clear detection in the CHEOPS dataset only. The TESS observations are
blind to this stellar signal. Based on CHEOPS observations, we show
that the inferred properties of stellar granulation are in agreement
with both Kepler observations and hydrodynamic models. Comparing their
periodograms, we observe a strong link between spectroscopic and
photometric observables. Correlations of this stellar signal in the
time domain (flux versus radial velocities) and with specific
spectroscopic observables (shape of the cross-correlation functions)
are however difficult to isolate due to signal-to-noise dependent
variations. In the context of the upcoming PLATO mission and the
extreme precision radial velocity surveys, a thorough understanding of
the properties of the stellar granulation signal is needed. The CHEOPS
and ESPRESSO observations pave the way for detailed analyses of this
stellar process.
Description:
Stellar and flicker characteristics of the targets.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablef1.dat 164 315 Stellar and flicker characteristics of the targets
hd67458.dat 32 2430 HD67458 CHEOPS light curve
hd88595.dat 32 2882 HD88595 CHEOPS light curve
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
Byte-by-byte Description of file: tablef1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Target Name of the target
14- 19 A6 --- Mission CHEOPS or Kepler
21- 31 F11.6 uHz Freqc Corner frequency
33- 42 F10.6 uHz Freqg Flicker frequency
44- 53 F10.6 ppm std-wgn Standard deviation of the white Gaussian noise
55- 62 F8.6 --- ag Flicker index
64- 71 F8.6 --- e_ag Flicker index uncertainty
73- 81 F9.6 --- ag-30ppm ?=-1 Flicker index interpolated at 30ppm
83- 90 F8.6 Msun Mstar Stellar mass
92- 99 F8.6 Msun e_Mstar Stellar mass uncertainty
101-108 F8.6 Rsun Rstar Stellar radius
110-117 F8.6 Rsun e_Rstar Stellar radius uncertainty
119-129 F11.6 K Teff Stellar Teff
131-140 F10.6 K e_Teff Stellar Teff uncertainty
142-149 F8.6 --- logg Stellar surface gravity
151-158 F8.6 --- e_logg Stellar surface gravity uncertainty
160-164 F5.2 mag Vmag Stellar apparent magnitude in the V-band
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Byte-by-byte Description of file: hd67458.dat hd88595.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d Time Baricentric Julian date (BJD)
16- 23 F8.6 --- RFlux Relative flux
25- 32 F8.6 --- e_RFlux Flux error
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Acknowledgements:
Sophia Sulis, sophia.sulis(at)lam.fr
History:
01-Feb-2023: on-line version
25-Feb-2023: light curves added
(End) Patricia Vannier [CDS] 28-Nov-2022