J/ApJS/271/60 Magnetic activity of G-type stars from LAMOST & TESS (Su+, 2024)
Magnetic activity of millions of G-type stars based on the LAMOST DR10 Low-
Resolution Spectral and TESS light-curve surveys and the future CSST survey
Su T., Zhang L.-Y., Long L., Misra P., Han X.L., Meng G., Yang Z., Pi Q.
<Astrophys. J. Suppl. Ser., 271, 60 (2024)>
=2024ApJS..271...60S 2024ApJS..271...60S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, G-type; Equivalent widths; Spectra, optical;
Spectral types; Radial velocities; Abundances, [Fe/H];
Photometry, ugriz; Proper motions; Stars, distances
Keywords: Stellar activity
Abstract:
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST)
data release 10 (DR10) provides over 3 million G-type stellar spectra,
which are important for the study of chromospheric activity of
solar-like stars. We have used the iSpec program to perform spectral
subtraction on the G-type stellar spectra obtained from LAMOST DR10
with a signal-to-noise ratio greater than 10. We have calculated the
magnetic activity of G-type stars using Hα lines and analyzed
the Hα variation. Among the more than 3 million spectra from
more than 2.3 million stars, a total of 220,000 stars show excess
chromospheric activity. There were a total of about 480,000 stars with
repeated observations. About 390,000 stars were found to exhibit
variations in the Hα line, and 14,000 stars showed changes in
their radial velocity. By using the Gaia data, we determined the
distances of these stars above the Galactic disk. We first concluded
that the fraction of G-type active stars decreases with increasing
distance above the Galactic disk. By using the Transiting Exoplanet
Survey Satellite light curves, we obtained the effective fluctuation
range of the light curve caused by the starspot and confirmed that
there was a positive correlation between the starspot and
chromospheric activity. We also concluded that R'Hα tends to
be stable for Rossby number (Ro)<0.13 and that R'Hα decreases
as Ro increases in the region Ro≥0.13.
Description:
In the present study, we have utilized the low-resolution spectral
data (R∼1800) of LAMOST DR10 to study the chromospheric activity of
G-type stars. We selected the spectral data with S/N r≥10 as our
objects for investigation.
We extracted the observational coordinates of each light curve from
TESS and performed crossmatching with the coordinates of the G-type
star sample from LAMOST DR10 using Topcat. See Section 2.3.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 199 3062102 Low-resolution spectral parameters of G-type stars
in LAMOST DR10
table2.dat 102 1236282 Low-resolution spectral parameters of G-type stars
with multiple observations from LAMOST DR10
table3.dat 68 2967117 The locations of G-type stars of LAMOST DR10
low-resolution survey in our Galaxy
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See also:
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-)
III/198 : Palomar/MSU nearby star spectroscopic survey (Hawley+ 1997)
III/218 : ELODIE archive (Prugniel+, 2001)
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
V/156 : LAMOST DR7 catalogs (Luo+, 2019)
IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
J/ApJ/315/687 : X-Ray emission from solar-type stars: F and G (Maggio+, 1987)
J/ApJS/85/315 : F, G and K dwarf stars of the Pleiades (Soderblom+ 1993)
J/A+A/331/581 : Rotation and activity in field M dwarfs (Delfosse+ 1998)
J/PASP/110/863 : A Stellar Spectral Flux Library: 1150 - 25000 A (Pickles 1998)
J/A+A/397/147 : Activity-rotation relationship in stars (Pizzolato+ 2003)
J/ApJS/152/251 : Indo-US library of coude feed stellar spectra (Valdes+, 2004)
J/AJ/128/426 : Subdwarfs in the SDSS (West+, 2004)
J/MNRAS/371/703 : MILES library of empirical spectra (Sanchez-Blazquez+, 2006)
J/AJ/135/785 : SDSS-DR5 low-mass star spectroscopic sample (West+, 2008)
J/MNRAS/389/585 : Fundamental parameters of M dwarfs (Casagrande+, 2008)
J/ApJ/743/48 : Stars with rot. periods and X-ray luminosities (Wright+, 2011)
J/AJ/143/93 : Rotational velocities in early-M stars (Reiners+, 2012)
J/ApJ/757/112 : Stellar diameters. II. K and M-stars (Boyajian+, 2012)
J/ApJ/783/130 : Parallaxes of high mass star forming regions (Reid+, 2014)
J/ApJ/795/161 : Activity & rotation in Praesepe & the Hyades (Douglas+, 2014)
J/A+A/594/A39 : LAMOST-Kepler param. and activity indicators (Frasca+, 2016)
J/ApJ/834/85 : Hα emission in nearby M dwarfs (Newton+, 2017)
J/ApJ/834/207 : Periodicity & mag. of Kepler LCs variation (Mehrabi+, 2017)
J/MNRAS/476/908 : Chromospheric activity in 4 open clusters (Fang+, 2018)
J/other/RAA/19.64 : LAMOST sp. binaries & variable stars (Qian+, 2019)
J/ApJS/247/9 : FGK stars magnetic activity in LAMOST-Kepler (Zhang+, 2020)
J/ApJS/253/19 : Halpha and other EWs of LAMOST M-type stars (Zhang+, 2021)
J/ApJS/260/45 : Stellar param. of M-type stars from LAMOST DR8 (Ding+, 2022)
J/ApJS/261/26 : Exoplanet host stars from LAMOST, TESS, Kepler (Su+, 2022)
J/MNRAS/514/4781 : Active stars in the LAMOST-K2 field (Xiang+, 2022)
J/ApJS/268/4 : Stellar variability with TESS (Fetherolf+, 2023)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- LAMOST LAMOST DR10 identifier (JHHMMSS.ss+DDMMSS.s)
21- 30 F10.4 d HJD Heliocentric modified Julian Date
(HJD-2400000.5)
32- 38 F7.2 s Exp [0/9600] Exposure time
40- 44 F5.2 mag gmag [1/28.3]? Apparent g band AB magnitude
46- 50 F5.2 mag rmag [-0.5/22.4]? Apparent r band AB magnitude
52- 56 F5.2 mag imag [-1.5/28.6]? Apparent i band AB magnitude
58- 62 F5.2 mag zmag [1/28]? Apparent z band AB magnitude
64- 68 F5.2 mag ymag [-3.6/26.4]? Apparent y band AB magnitude
70- 77 F8.2 --- S/Nu [0/446]?=-9999 Signal-to-Noise of u band
observation
79- 86 F8.2 --- S/Ng [1.7/999]?=-9999 Signal-to-Noise of g band
observation
88- 93 F6.2 --- S/Nr [10/999] Signal-to-Noise of r band
observation
95- 102 F8.2 --- S/Ni [0/999]?=-9999 Signal-to-Noise of i band
observation
104- 111 F8.2 --- S/Nz [0/999]?=-9999 Signal-to-Noise of z band
observation
113- 114 A2 --- SpT Spectral type
116- 122 F7.2 K Teff [3870/7063] Effective temperature from LAMOST
124- 131 F8.2 K e_Teff [0/998]?=-9999 Uncertainty in Teff
133- 137 F5.3 [cm/s2] logg [0.06/5] Log surface gravity from LAMOST
139- 147 F9.3 [cm/s2] e_logg [0/1.2]?=-9999 Uncertainty in logg
149- 154 F6.3 [Sun] [Fe/H] [-2.5/0.8] Metallicity from LAMOST
156- 164 F9.3 [Sun] e_[Fe/H] [0/1]?=-9999 Uncertainty in [Fe/H]
166- 172 F7.2 km/s RVel [-424/433] Radial velocity from LAMOST
174- 181 F8.2 km/s e_RVel [0/100]?=-9999 Uncertainty in RVel
183- 190 F8.3 0.1nm EWcHa [-181/30] Continuum corrected Hα
equivalent width (EW'Hα) in Angstrom
units
192- 197 F6.3 0.1nm e_EWcHa [0.001/73] Uncertainty in EWcHa
199 A1 --- Act [NY] Judgment of stellar activity
(Y=activity; or N=inactivity)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- LAMOST LAMOST DR10 identifier (JHHMMSS.ss+DDMMSS.s)
21- 31 F11.5 d HJD Heliocentric modified Julian Date
(HJD-2400000.5)
33- 40 F8.3 0.1nm EWcHa [-181/16] Continuum corrected Hα
equivalent width (EW'Hα) in
Angstrom units
42- 47 F6.3 0.1nm e_EWcHa [0.001/73] Uncertainty in EWcHa
49- 55 F7.3 0.1nm (max-min)Ha [0/181] Difference between maximum and
minimum EW' values
57- 65 F9.3 0.1nm (max/min)Ha [-1429/2346]? Ratio of EWc maximum to
minimum
67 A1 --- VHa [NY] The Hα EWc variability judgment
(1)
69- 75 F7.2 km/s RVel [-303/358] LAMOST radial velocity
77- 84 F8.2 km/s e_RVel [0/99]?=-9999 Uncertainty in RVel
86- 91 F6.2 km/s (max-min)RV [0/221] Difference between maximum and
minimum RVel values
93- 100 F8.2 km/s (max/min)RV [-1801/1646]? Ratio of RVel maximum to
minimum
102 A1 --- Vrv [NY] The radial velocity variability
judgment (1)
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Note (1): Code as follows:
Y = variability;
N = non variability.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- LAMOST LAMOST DR10 identifier (JHHMMSS.ss+DDMMSS.s)
21- 27 F7.2 mas/yr pmRA [-242/358] Gaia DR3 proper motion along RA
29- 35 F7.2 mas/yr pmDE [-447/232] Gaia DR3 proper motion along DE
37- 43 F7.1 pc Dist [40/32702]? Gaia DR3 distance
45- 51 F7.2 km/s RVel [-424/423] LAMOST radial velocity
53- 60 F8.1 pc Z [-22430/31806]? Distance from the Galactic disk
62- 68 F7.1 pc R [207/22760]? Horizontal distance from Galactic
center
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 16-Jul-2024