J/ApJS/272/40 Kepler stellar phot. noise & LAMOST S-index (Zhang+, 2024) ================================================================================ Reconstructing intrinsic stellar noise with stellar atmospheric parameters and chromospheric activity. Zhang J., Xiang M., Yu J., Ge J., Xie J.-W., Zhang H., Li Y., Wu Y., Li C.-Q., Bi S., Yan H.-L., Shi J.-R. =2024ApJS..272...40Z ================================================================================ ADC_Keywords: Abundances, [Fe/H]; Magnitudes; Optical; Surveys Keywords: Stellar activity ; Stellar properties ; Stellar photometry Abstract: Accurately characterizing the intrinsic stellar photometric noise induced by stellar astrophysics, such as stellar activity, granulation, and oscillations, is of crucial importance for detecting transiting exoplanets. In this study, we investigate the relation between the intrinsic stellar photometric noise, quantified by the Kepler combined differential photometric precision (CDPP) metric, and the level of stellar chromospheric activity, indicated by the S-index of CaII H K lines derived from LAMOST spectra. Our results reveal a clear positive correlation between the S-index and robust rms values of CDPP, with the correlation becoming more significant at higher activity levels and on longer timescales. We have therefore built an empirical relation between the robust rms values of CDPP and the S-index as well as Teff, logg, [Fe/H], and the apparent magnitude, with the XGBoost regression algorithm, using the LAMOST-Kepler common star sample as the training set. This method achieves a precision of ~20ppm for inferring the intrinsic noise from the S-index and other stellar labels on a 6 hr integration duration. We have applied this empirical relation to the full LAMOST DR7 spectra database and obtained the intrinsic noise predictions for 1,358,275 stars. The resultant catalog is publicly available and expected to be valuable for optimizing target selection for future exoplanet-hunting space missions, such as the Earth 2.0 mission. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table2.dat 79 1358275 Deduced photometric noise of the 1,358,275 stars -------------------------------------------------------------------------------- Description of file: Table2.fits is the original FITS file as downloaded from the online paper See also: III/159 : Ca II H and K Measurements Made at MWO (Duncan+ 1991) V/133 : Kepler Input Catalog (Kepler Mission Team, 2009) V/156 : LAMOST DR7 catalogs (Luo+, 2019) I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022) J/ApJS/152/261 : Chromospheric Ca II emission in nearby stars (Wright+, 2004) J/ApJ/725/875 : Chromospheric activity for CPS stars (Isaacson+, 2010) J/A+A/523/A48 : Gaia photometry (Jordi+, 2010) J/A+A/531/A8 : Activity indices & velocities for 890 stars (Jenkins+, 2011) J/PASP/124/1279 : Q3 Kepler's combined photometry (Christiansen+, 2012) J/ApJS/199/24 : The first three quarters of Kepler mission (Tenenbaum+, 2012) J/ApJS/220/19 : LAMOST obs. in the Kepler field. I. (De Cat+, 2015) J/AJ/150/133 : Stellar noise for Kepler solar-type dwarfs (Gilliland+, 2015) J/MNRAS/448/822 : LAMOST candidate members of star clusters (Xiang+, 2015) J/AJ/151/68 : Kepler Mission. VII. Eclipsing binaries in DR3 (Kirk+, 2016) J/AJ/152/158 : Final Kepler transiting planet search (DR25) (Twicken+, 2016) J/ApJ/835/25 : Calibrated solar S-index time series (Egeland+, 2017) J/ApJS/229/30 : Revised properties of Q1-17 Kepler targets (Mathur+, 2017) J/ApJS/235/38 : Kepler planetary cand. VIII. (Thompson+, 2018) J/ApJS/245/34 : Abundances for 6 million stars from LAMOST DR5 (Xiang+, 2019) J/ApJS/247/9 : FGK stars magnetic activity in LAMOST-Kepler (Zhang+, 2020) J/AJ/162/100 : PAST. II. LAMOST-Gaia-Kepler catalog of stars (Chen+, 2021) J/A+A/646/A77 : Chromospheric activity; AMBRE-HARPS (Gomes da Silva+, 2021) J/A+A/681/A107 : Mercator Lib. of HR Stellar Spectroscopy (Royer+, 2024) J/ApJS/271/19 : FGK dwarfs from LAMOST DR7 & Gaia DR3 and Kepler (Ye+, 2024) Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 19 I19 --- GaiaDR3 Gaia DR3 identifier (GaiaDR3_SourceID) 21- 25 F5.2 mag Gmag [9.42/15.35] Gaia G-band magnitude (Gmag) 27- 33 F7.2 K Teff [3837.4/6500] Effective temperature (teff) 35- 38 F4.2 [cm/s2] logg [1.3/4.7] Log of surface gravity (logg) 40- 44 F5.2 [Sun] [Fe/H] [-0.95/0.4] Abundance [Fe/H] (feh) 46- 49 F4.2 --- Sindex [0.07/0.41] S-index (Sindex) 51- 54 F4.2 [-] CDPP1.5h [1.42/2.61] Log of 1.5h overall noise (rrmsCDPP_01p5) 56- 59 F4.2 [-] CDPP6.0h [1.29/2.54] Log of 6h overall noise (rrmsCDPP_06p0) 61- 64 F4.2 [-] CDPP15h [1.26/2.52] Log of 15h overall noise (rrmsCDPP_15p0) 66- 69 F4.2 [-] CDPPi1.5h [1.26/2.43] Log of 1.5h intrinsic noise (rrmsCDPP_01p5_i) 71- 74 F4.2 [-] CDPPi6.0h [1.03/2.45] Log of 6h intrinsic noise (rrmsCDPP_06p0_i) 76- 79 F4.2 [-] CDPPi15h [0.98/2.66] Log of 15h intrinsic noise (rrmsCDPP_15p0_i) -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Emmanuelle Perret [CDS] 22-Aug-2024