J/ApJ/928/188 Seismic parameters of Kepler red giant stars (Dhanpal+, 2022) ================================================================================ Measuring frequency and period separations in red-giant stars using machine learning. Dhanpal S., Benomar O., Hanasoge S., Kundu A., Dhuri D., Das D., Kaul B. =2022ApJ...928..188D ================================================================================ ADC_Keywords: Asteroseismology; Stars, giant Keywords: Asteroseismology ; Neural networks ; Red giant branch ; Pulsation modes ; Stellar oscillations Abstract: Asteroseismology is used to infer the interior physics of stars. The Kepler and TESS space missions have provided a vast data set of red-giant lightcurves, which may be used for asteroseismic analysis. These data sets are expected to significantly grow with future missions such as PLATO, and efficient methods are therefore required to analyze these data rapidly. Here, we describe a machine-learning algorithm that identifies red giants from the raw oscillation spectra and captures p- and mixed-mode parameters from the red-giant power spectra. We report algorithmic inferences for large frequency separation ({Delta}{nu}), frequency at maximum amplitude ({nu}_max_), and period separation ({Delta}{Pi}) for an ensemble of stars. In addition, we have discovered ~25 new probable red giants among 151000 Kepler long-cadence stellar-oscillation spectra analyzed by this method, among which four are binary candidates that appear to possess red-giant counterparts. To validate the results of this method, we selected ~3000 Kepler stars, at various evolutionary stages ranging from subgiants to red clumps, and compare inferences of {Delta}{nu}, {Delta}{Pi}, and {nu}_max_ with estimates obtained using other techniques. The power of the machine-learning algorithm lies in its speed: It is able to accurately extract seismic parameters from 1000 spectra in ~5s on a modern computer (a single core of the Intel(r) Xeon(r) Platinum 8280 CPU). Description: To construct the periodograms of Kepler data, we use the MAST data from which we extract the PDCSAP lightcurves. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file tablec1.dat 53 25 List of new giant stars that were discovered by machine tablec2.dat 53 195 List of 195 red-giant stars detected in Hon+ 2019, J/MNRAS/485/5616 -------------------------------------------------------------------------------- See also: V/133 : Kepler Input Catalog (Kepler Mission Team, 2009) J/A+A/525/A131 : Solar-like oscillations in Kepler red giants (Hekker+, 2011) J/ApJ/749/152 : Asteroseismic analysis of solar-type stars (Mathur+, 2012) J/A+A/540/A143 : Oscillations of Kepler red giants (Mosser+, 2012) J/ApJ/765/L41 : Asteroseismic classification of KIC objects (Stello+, 2013) J/ApJS/210/1 : Asteroseismic study of solar-type stars (Chaplin+, 2014) J/A+A/572/L5 : Evolution of red giants from seismology (Mosser+, 2014) J/ApJS/215/19 : APOKASC catalog of Kepler red giants (Pinsonneault+, 2014) J/ApJ/827/50 : Kepler faint red giants (Mathur+, 2016) J/A+A/588/A87 : Seismic global parameters of 6111 KIC (Vrard+, 2016) J/A+A/600/A1 : Coupling factors of 5166 KIC (Mosser+, 2017) J/A+A/598/A62 : KIC red giants showing depressed mixed modes (Mosser+, 2017) J/A+A/616/A24 : Rotation in RGBs from Kepler asteroseismology (Gehan+, 2018) J/A+A/618/A109 : Seismic global parameters of 372 KIC (Mosser+, 2018) J/ApJS/239/32 : APOKASC-2 cat. of Kepler evolved stars (Pinsonneault+, 2018) J/A+A/616/A94 : KIC red giants radial mode amplitudes (Vrard+, 2018) J/ApJS/236/42 : Asteroseismology of ~16000 Kepler red giants (Yu+, 2018) J/MNRAS/489/4641 : APOKASC Evol. state of red-giant stars (Elsworth+, 2019) J/MNRAS/485/5616 : Red giant solar-like oscillations in Kepler (Hon+, 2019) J/A+A/639/A63 : Active red giants asteroseismic & rotation (Gaulme+, 2020) J/MNRAS/493/1388 : Asteroseismology of Kepler luminous red giants (Yu+, 2020) J/A+A/648/A113 : Kepler red giants in EBs RVs (Benbakoura+, 2021) Byte-by-byte Description of file: tablec[12].dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 I3 --- Seq [1/195] Running sequence number 5- 13 I09 --- KIC [1161491/100000928] KIC identifier (1) 15- 19 F5.2 uHz delnu [4.2/19] Frequency separation, {Delta}{nu} 21- 24 F4.2 uHz e_delnu [0.03/1.7] delnu uncertainty 26- 31 F6.2 s delpi [41.2/332.1] Period separation, {Delta}{Pi} 33- 38 F6.2 s e_delpi [0.8/207] delpi uncertainty 40- 46 F7.3 uHz numax [28.6/256.5] The p-mode frequency at maximum power, {nu}_max_ 48- 53 F6.3 uHz e_numax [0.026/18.4] numax uncertainty -------------------------------------------------------------------------------- Note (1): Kepler ID 100000928 can be found on MAST (http://archive.stsci.edu/kepler/data_search/search.php) but with multiple coordinates (ranging from 19 20 53.853 +37 50 53.12 to 19 20 57.785 +37 51 00.56). It is not in the KIC target catalog. -------------------------------------------------------------------------------- History: From electronic version of the journal Acknowledgements: Siddharth Dhanpal [dhanpal.siddharth _at_ gmail dot com] ================================================================================ (End) Emmanuelle Perret [CDS] 04-Mar-2024