J/AJ/161/170 The Swan: an approach to derive surface gravity (Sayeed+, 2021)
The Swan: data-driven inference of stellar surface gravities for cool stars from
photometric light curves.
Sayeed M., Huber D., Wheeler A., Ness M.K.
<Astron. J., 161, 170-170 (2021)>
=2021AJ....161..170S 2021AJ....161..170S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, masses; Stars, diameters; Photometry, K-line;
Effective temperatures
Keywords: Asteroseismology; Time domain astronomy; Linear regression; Photometry
Light curves; Stellar oscillations; Astronomy data modeling
Stellar astronomy; Stellar granulation
Abstract:
Stellar light curves are well known to encode physical stellar
properties. Precise, automated, and computationally inexpensive
methods to derive physical parameters from light curves are needed to
cope with the large influx of these data from space-based missions
such as Kepler and TESS. Here we present a new methodology that we
call "The Swan", a fast, generalizable, and effective approach for
deriving stellar surface gravity (logg) for main-sequence, subgiant,
and red giant stars from Kepler light curves using local linear
regression on the full frequency content of Kepler long-cadence power
spectra. With this inexpensive data-driven approach, we recover logg
to a precision of ∼0.02dex for 13822 stars with seismic logg values
between 0.2 and 4.4dex and ∼0.11dex for 4646 stars with Gaia-derived
logg values between 2.3 and 4.6dex. We further develop a
signal-to-noise metric and find that granulation is difficult to
detect in many cool main-sequence stars (Teff≲5500K), in particular K
dwarfs. By combining our logg measurements with Gaia radii, we derive
empirical masses for 4646 subgiant and main-sequence stars with a
median precision of ∼7%. Finally, we demonstrate that our method can
be used to recover logg to a similar mean absolute deviation precision
for a TESS baseline of 27days. Our methodology can be readily applied
to photometric time series observations to infer stellar surface
gravities to high precision across evolutionary states.
Description:
We present a simple but effective data-driven approach to predict
stellar surface gravity from power spectra of time series photometry,
which we term "The Swan."
This paper includes data collected by the Kepler mission and obtained
from the Mikulski Archive for Space Telescopes (MAST) data archive at
the Space Telescope Science Institute (STScI).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 14 899 White noise level as a function of Kepler
magnitude calculated using 3270 Kepler stars
observed in short cadence
table3.dat 137 14003 Stellar properties and output parameters for
stars in the asteroseismic sample
table4.dat 137 4697 Stellar properties and output parameters for
stars in the Gaia sample
--------------------------------------------------------------------------------
See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/529/A89 : Kepler satellite variability study (Debosscher+, 2011)
J/AJ/142/112 : KIC photometric calibration (Brown+, 2011)
J/A+A/543/A160 : Normalized spectra of 82 Kepler red giants (Thygesen+, 2012)
J/ApJ/757/161 : Spectroscopy of 56 exoplanet host stars (Torres+, 2012)
J/MNRAS/423/122 : Abundances of 93 solar-type Kepler targets (Bruntt+, 2012)
J/MNRAS/432/1203 : Rotation periods of M-dwarf stars (McQuillan+, 2013)
J/ApJ/765/L41 : Asteroseismic classification of KIC objects (Stello+, 2013)
J/ApJ/771/40 : Main-sequence A, F, G, and K stars photometry (Boyajian+, 2013)
J/ApJ/787/110 : SAGA: Stromgren survey of seismic KIC stars (Casagrande+, 2014)
J/ApJS/210/1 : Asteroseismic study of solar-type stars (Chaplin+, 2014)
J/ApJS/211/2 : Revised stellar properties Q1-16 Kepler targets (Huber+, 2014)
J/ApJS/215/19 : APOKASC catalog of Kepler red giants (Pinsonneault+, 2014)
J/ApJ/808/16 : The Cannon: new approach to determine abundances (Ness+, 2015)
J/MNRAS/452/2127 : Fundamental parameters Kepler stars (Silva Aguirre+, 2015)
J/AJ/151/144 : ASPCAP weights for 15 APOGEE chemical elements (Garcia+, 2016)
J/ApJ/818/43 : Stellar surface gravity measures of KIC stars (Bastien+, 2016)
J/ApJ/823/114 : The Cannon: a new approach to determine masses (Ness+, 2016)
J/ApJ/827/50 : Kepler faint red giants (Mathur+, 2016)
J/A+A/597/A30 : Seismology & spectroscopy of CoRoGEE red giants (Anders+, 2017)
J/ApJ/835/173 : Kepler asteroseismic LEGACY sample. II. (Silva Aguirre+, 2017)
J/ApJ/836/5 : Abundances of LAMOST giants from APOGEE DR12 (Ho+, 2017)
J/ApJ/844/102 : KIC star plxs from asteroseismology vs Gaia (Huber+, 2017)
J/ApJS/229/30 : Revised stellar properties Q1-17 Kepler targets (Mathur+, 2017)
J/AJ/156/264 : California-Kepler Survey VII. Planet radius gap (Fulton+, 2018)
J/ApJ/865/68 : Abundances for 79 Sun-like stars within 100pc (Bedell+, 2018)
J/ApJ/866/99 : Revised radii of KIC stars & planets Gaia DR2 (Berger+, 2018)
J/ApJS/235/38 : Kepler planetary cand. VIII. DR25 reliability (Thompson+, 2018)
J/ApJS/236/42 : Asteroseismology of ∼16000 Kepler red giants (Yu+, 2018)
J/MNRAS/478/4513 : GALAH Survey DR2 (Buder+, 2018)
J/ApJS/245/34 : Abundances for 6 million stars from LAMOST DR5 (Xiang+, 2019)
J/ApJS/241/12 : The Asteroseismic Target List (ATL) for TESS (Schofield+, 2019)
J/AJ/159/193 : Stellar parameters ∼30000 LAMOST DR1 Mdwarfs (Galgano+, 2020)
J/AJ/159/280 : Gaia-Kepler stellar prop. catalog.I. KIC stars (Berger+, 2020)
J/AJ/160/18 : M giant stars asteroseism. with Kepler and APOGEE (Auge+, 2020)
http://github.com/MaryumSayeed/TheSwan : The Swan code archived on Zenodo
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 F5.2 mag Kmag [8.01/17] Kepler magnitude
7- 14 F8.3 --- WNL [0.16/6231] White Noise Level in ppm2/uHz
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC Kepler Input Catalog identifier
10- 15 F6.3 mag Kmag [7.39/15.9] Kepler broad band apparent magnitude
17- 20 I4 K Teff [3247/6752] Effective temperature (1)
22- 28 F7.3 solRad Rad [1.03/162] Radius
30- 35 F6.3 solRad E_Rad [0.01/24] Upper 1σ uncertainty in Rad
37- 43 F7.3 solRad e_Rad [0.01/20] Lower 1σ uncertainty in Rad
45- 49 F5.3 [cm/s2] logg [0.16/4.4] log surface gravity (2)
51- 55 F5.3 [cm/s2] E_logg [0.006/0.14] Upper 1σ uncertainty in logg
57- 62 F6.3 [cm/s2] e_logg [0.006/0.14] Lower 1σ uncertainty in logg
64- 69 F6.3 [cm/s2] loggI [0.03/4.4] log inferred surface gravity (3)
71- 77 F7.3 [cm/s2] E_loggI [0.02/0.42]?=-99 Upper 1σ uncertainty in
loggI (4)
79- 85 F7.3 [cm/s2] e_loggI [0.02/0.42]?=-99 Lower 1σ uncertainty in
loggI (4)
87- 91 F5.3 solMass MassT [0.45/5.24] True mass (2)
93- 97 F5.3 solMass E_MassT [0.02/1.8] Upper 1σ uncertainty in MassT
99-104 F6.3 solMass e_MassT [0.007/2.6] Lower 1σ uncertainty in MassT
106-113 F8.3 solMass MassI [0.18/8]?=-999 Inferred mass (5)
115-121 F7.3 solMass E_MassI [0.001/623] Upper 1σ uncertainty in MassI
123-129 F7.3 solMass e_MassI [0.001/623] Lower 1σ uncertainty in MassI
131-135 F5.3 --- SNR [0.02/1] Signal-to-Noise ratio
137 A1 --- Flag [0/1] Outliers are indicated by outlier
flag equal to 1 (181 occurrences)
--------------------------------------------------------------------------------
Note (1): From Berger+, 2020, J/AJ/159/280.
Note (2): From Mathur+, 2017, J/ApJS/229/30 and Yu+, 2018, J/ApJS/236/42.
Note (3): Inferred mass uncertainties were calculated using radius
errors from Berger+, 2020, J/AJ/159/280, and derived logg errors were
calculated using a signal-to-noise metric.
Note (4): -99 corresponds to an unsuccessful inference.
Note (5): -999 is set for outliers with inaccurate inferred logg values.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC Kepler Input Catalog identifier
10- 15 F6.3 mag Kmag [8.69/13.5] Kepler broad band apparent magnitude
17- 20 I4 K Teff [4477/8444] Effective temperature (1)
22- 28 F7.3 solRad Rad [0.72/14.9] Radius (1)
30- 35 F6.3 solRad E_Rad [0.01/1.6] Upper 1σ uncertainty in Rad
37- 43 F7.3 solRad e_Rad [0.01/1.7] Lower 1σ uncertainty in Rad
45- 49 F5.3 [cm/s2] logg [2.33/4.59] log surface gravity (1)
51- 55 F5.3 [cm/s2] E_logg [0.01/0.3] Upper 1σ uncertainty in logg
57- 62 F6.3 [cm/s2] e_logg [0.01/0.27] Lower 1σ uncertainty in logg
64- 69 F6.3 [cm/s2] loggI [1.46/4.52] log inferred surface gravity
71- 77 F7.3 [cm/s2] E_loggI [0.02/0.2] Upper 1σ uncertainty in loggI
79- 85 F7.3 [cm/s2] e_loggI [0.02/0.2] Lower 1σ uncertainty in loggI
87- 91 F5.3 solMass MassT [0.73/2.9] True mass (1)
93- 97 F5.3 solMass E_MassT [0.01/0.87] Upper 1σ uncertainty in MassT
99-104 F6.3 solMass e_MassT [0.01/0.87] Lower 1σ uncertainty in MassT
106-113 F8.3 solMass MassI [0.36/5.26]?=-999 Inferred mass (2)
115-121 F7.3 solMass E_MassI [0.003/4.32] Upper 1σ uncertainty in MassI
123-129 F7.3 solMass e_MassI [0.003/3.46] Lower 1σ uncertainty in MassI
131-135 F5.3 --- SNR [0.54/1] Signal-to-Noise ratio
137 A1 --- Flag [0/1] Outliers are indicated by outlier flag
equal to 1 (51 occurrences)
--------------------------------------------------------------------------------
Note (1): From Berger+, 2020, J/AJ/159/280. Derived mass uncertainties
were calculated using radius errors and derived logg errors were
calculated using a signal-to-noise metric.
Note (2): -999 is set for outliers with inaccurate inferred logg values.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 29-Jul-2021