J/A+A/639/A35 RV jitter and photometric var. correlation (Hojjatpanah+, 2020)
The correlation between photometric variability and radial velocity jitter.
Based on TESS and HARPS observations.
Hojjatpanah S., Oshagh M., Figueira P., Santos N.C., Amazo-gomez E.M.,
Sousa S.G., Adibekyan V., Akinsanmi B., Demangeon O., Faria J.,
Gomes Da Silva J., Meunier N.
<Astron. Astrophys., 639, A35 (2020)>
=2020A&A...639A..35H 2020A&A...639A..35H (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Radial velocities ;
Magnitudes
Keywords: techniques: spectroscopic - planets and satellites: detection -
techniques: radial velocities - techniques: photometric -
stars: activity
Abstract:
Characterizing the relation between stellar photometric variability
and radial velocity (RV) jitter can help us to better understand the
physics behind these phenomena. The current and upcoming high
precision photometric surveys such as TESS, CHEOPS, and PLATO will
provide the community with thousands of new exoplanet candidates. As a
consequence, the presence of such a correlation is crucial in
selecting the targets with the lowest RV jitter for efficient RV
follow-up of exoplanetary candidates. Studies of this type are also
crucial to design optimized observational strategies to mitigate RV
jitter when searching for Earth-mass exoplanets. Aims. Our goal is to
assess the correlation between high-precision photometric variability
measurements and high-precision RV jitter over different time scales.
We analyze 171 G, K, and M stars with available TESS high precision
photometric time-series and HARPS precise RVs. We derived the stellar
parameters for the stars in our sample and measured the RV jitter and
photometric variability. We also estimated chromospheric CaII H & K
activity indicator log(R'HK), vsini, and the stellar rotational
period. Finally, we evaluate how different stellar parameters and an
RV sampling subset can have an impact on the potential correlations.
We find a varying correlation between the photometric variability and
RV jitter as function of time intervals between the TESS photometric
observation and HARPS RV. As the time intervals of the observations
considered for the analysis increases, the correlation value and
significance becomes smaller and weaker, to the point that it becomes
negligible. We also find that for stars with a photometric variability
above 6.5 ppt the correlation is significantly stronger. We show that
such a result can be due to the transition between the spot-dominated
and the faculae-dominated regime. We quantified the correlations and
updated the relationship between chromospheric CaII H & K activity
indicator log(R'HK) and RV jitter.
Description:
We present a study on the correlation between RV jitter and
photometric variability. We used a sample of 171 starts that have been
observed by both the HARPS spectrograph and TESS space telescope. We
derived the RV-RMS and peak-to-peak of light curve variability as well
as the stellar parameters.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablec1.dat 92 171 Derived parameters for the stars
tablec2.dat 59 279 Stars in Fig. 14 with the peak-to-peak of
light curve variation <6.5 ppt and some stellar
parameters presents in TIC (Stassun et al.,
2018, Cat. J/AJ/156/102)
--------------------------------------------------------------------------------
See also:
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
J/AJ/156/102 : TESS Input Catalog and Candidate Target List (Stassun+, 2018)
Byte-by-byte Description of file: tablec1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Index [1/171] Sequential number
5- 14 A10 --- Name Star name
16- 21 F6.1 K Teff Effective temperature
23- 25 I3 K e_Teff rms uncertainty on Teff
27- 33 F7.3 m/s RV-RMS Velocity difference, RV-RMS, where RMS is
the root-mean-square of RV time series (1)
35- 40 F6.3 --- ppLC Peak-to-peak light curves, in ppt unit
42- 45 F4.1 km/s vsini Rotational velocity (mean error: 1.0km/s)
47- 51 F5.2 [-] logR'HK Mean logR'HK index (mean error: 0.01)
53- 56 F4.2 [cm/s2] logg ? Surface gravity
58- 61 F4.2 [cm/s2] e_logg ? rms uncertainty on logg
63- 68 F6.3 [-] [Fe/H] ? Metallicity
70- 74 F5.3 [-] e_[Fe/H] ? rms uncertainty on [Fe/H]
76- 79 F4.1 d Prot ? Rotational period
81- 84 F4.1 d e_Prot ? rms uncertainty on Prot
86- 92 A7 --- Sample Sample(s) (2)
--------------------------------------------------------------------------------
Note (1): Using the whole sample
Note (2): subsample classifications, w: only considered in whole sample.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablec2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 I10 --- TIC TIC identification number
12- 18 F7.2 --- TOI Full TOI identification number
20- 23 F4.2 --- ppLC Peak-to-peak light curve, in ppt unit
25- 28 F4.1 mag Tmag TESS magnitude
30- 35 F6.1 K Teff Effective temperature
37- 42 F6.1 K e_Teff ? rms uncertainty on Teff
44- 46 F3.1 Rsun Rstar Radius
48- 51 F4.1 Rsun e_Rstar ? rms uncertainty on Rstar
53- 55 F3.1 [cm/s2] logg ? Surface gravity
57- 59 F3.1 [cm/s2] e_logg ? rms uncertainty on logg
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 10-Sep-2020