J/ApJS/281/5 K stars abundance and activity from LAMOST DR10 (Zhang+, 2025)
Physical parameters and activity properties of K-type stars based on the LAMOST
spectral survey.
Zhang Z., Zhang L.-Y., Su T., Han X.L., Misra P., Pi Q., Lu H.
<Astrophys. J. Suppl. Ser., 281, 5 (2025)>
=2025ApJS..281....5Z 2025ApJS..281....5Z
ADC_Keywords: Stars, K-type; Spectra, optical; Abundances, [Fe/H];
Equivalent widths; Spectral types
Keywords: K stars ; Stellar chromospheres ; Stellar activity
Abstract:
K-type stars are important objects of our Galaxy. It is interesting to
determine the stellar physical parameters and magnetic activity
properties of K-type stars. The Large Sky Area Multi-Object Fiber
Spectroscopic Telescope (LAMOST) DR10 provides more than 1 million
spectra of K-type stars. We have used spectra with a signal-to-noise
ratio greater than 10 as our objects in the large amount of spectral
data that we have analyzed. We used the spectral subtraction method to
reduce the observational spectra by utilizing the iSpec program. We
have determined the chromospheric activity of K-type stars using the
Hα line. Among more than 1.33 million spectra associated with
about 1.06 million stars, there are a total of 150,000 stellar spectra
that have excess chromospheric activity. For K stars with rotation
periods above 6.20 days, the chromospheric activity decreases rapidly
as the period increases. We calculated the solar Rossby number
ROsun=1.85, and conclude that when the Rossby number
RO/ROsun<0.07, R'Halpha remains stable; when RO/ROsun≫0.07,
R'Halpha decreases as RO/ROsun increases. By crossmatching with
the Gaia survey, we also determined their distances and found that the
active fraction decreases as the distance above the Galactic disk
increases.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 164 1151571 Spectral parameters of K stars from LAMOST DR10
observation with WISEA identifier
table1b.dat 175 23020 Spectral parameters of K stars from LAMOST DR10
observation without WISEA identifier;
table added by the author
table2.dat 92 879533 Location of K-type stars of our samples in our
Galaxy
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See also:
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-)
II/328 : AllWISE Data Release (Cutri+ 2013)
V/146 : LAMOST DR1 catalogs (Luo+, 2015)
V/164 : LAMOST DR5 catalogs (Luo+, 2019)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
V/162 : LAMOST DR11 catalogs (Luo+, 2026)
J/AJ/128/426 : Subdwarfs in the SDSS (West+, 2004)
J/MNRAS/389/585 : Fundamental parameters of M dwarfs (Casagrande+, 2008)
J/AJ/135/785 : SDSS-DR5 low-mass star spectroscopic sample (West+, 2008)
J/ApJ/743/48 : Stars with rot. periods & X-ray luminosities (Wright+, 2011)
J/AJ/143/93 : Rotational velocities in early-M stars (Reiners+, 2012)
J/ApJ/795/161 : Activity and rot. in Praesepe and the Hyades (Douglas+, 2014)
J/ApJS/211/24 : Rotation periods of Kepler MS stars (McQuillan+, 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/MNRAS/476/908 : Chromospheric activity in 4 open clusters (Fang+, 2018)
J/ApJS/244/21 : Surface rot. & activity of Kepler stars. I. (Santos+, 2019)
J/A+A/635/A43 : Stellar rot. periods from K2 Campaigns 0-18 (Reinhold+, 2020)
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/268/4 : Stellar var. with TESS 2min cadence phot. (Fetherolf+, 2023)
J/ApJS/264/17 : Spectroscopic data of TESS objects with LAMOST (Zhang+, 2023)
J/ApJS/271/60 : Magnetic activity of G stars from LAMOST+TESS (Su+, 2024)
J/A+A/688/A23 : Stellar chromospheric activity from LAMOST (Zhang+, 2024)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- WISEA ALLWISE Identifier, from TESS cross-match
(JHHMMSS.ss+DDMMSS.s) if any
21- 22 A2 --- subCl K type spectral subclass
24- 31 F8.2 --- snru [0/374]?=-9999 S/N of u band LAMOST spectra
33- 40 F8.2 --- snrg [0.7/999]?=-9999 S/N of g band LAMOST spectra
42- 49 F8.2 --- snrr [0/999]?=-9999 S/N of r band LAMOST spectra
51- 58 F8.2 --- snri [0/999]?=-9999 S/N of i band LAMOST spectra
60- 67 F8.2 --- snrz [0/999]?=-9999 S/N of z band LAMOST spectra
69- 75 F7.2 K Teff [3752/7282] Surface effective temperature (G1)
77- 84 F8.2 K e_Teff [0/997]?=-9999 Uncertainty in Teff (G1)
86- 91 F6.3 [-] feh [-2.5/0.75] Metallicity (G1)
93- 101 F9.3 [-] e_feh [0/1]?=-9999 Uncertainty in feh (G1)
103- 107 F5.3 [cm/s2] logg [0.08/4.9] Log, Surface gravity (G1)
109- 117 F9.3 [cm/s2] e_logg [0/1.2]?=-9999 Uncertainty in logg (G1)
119- 141 E23.16 0.1nm EWpHa [-905/111] Equivalent Width, Hα,
in Angstroms (G2)
143- 162 F20.16 0.1nm e_EWpHa [0.001/52] Uncertainty in EWpHa (G2)
164 A1 --- State [YN] Active state
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Byte-by-byte Description of file: table1b.dat
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Bytes Format Units Label Explanations
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1- 10 I10 --- objID [102110/1018101158] Unique spectrum ID
from LAMOST
12- 22 F11.7 deg RAdeg LAMOST right ascension (J2000)
24- 33 F10.7 deg DEdeg [-9.1/87] LAMOST declination (J2000)
35- 42 F8.2 --- snru [0/160]?=-9999 S/N of u band LAMOST spectra
44- 51 F8.2 --- snrg [2.8/804]?=-9999 S/N of g band LAMOST spectra
53- 60 F8.2 --- snrr [4.6/999]?=-9999 S/N of g band LAMOST spectra
62- 69 F8.2 --- snri [0/999]?=-9999 S/N of g band LAMOST spectra
71- 78 F8.2 --- snrz [0/999]?=-9999 S/N of g band LAMOST spectra
80- 81 A2 --- subCl K type spectral subclass
83- 89 F7.2 K Teff [3769/6817] Surface effective temperature (G1)
91- 98 F8.2 K e_Teff [0/614]?=-9999 Teff uncertainty
100- 105 F6.3 [-] feh [-1.83/0.66] Metallicity (G1)
107- 115 F9.3 [-] e_feh [0/0.7]?=-9999 feh uncertainty
117- 121 F5.3 [cm/s2] logg [0.1/4.9] Log of surface gravity (G1)
123- 131 F9.3 [cm/s2] e_logg [0/1.015]?=-9999 logg uncertainty
133- 154 E22.17 0.1nm EWpHa [-6.8/61.6] Equivalent Width, Hα,
in Angstroms (G2)
156- 173 F18.16 0.1nm e_EWpHa [0.0017/1.4] EWpHa uncertainty
175 A1 --- State [YN] Active state
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- WISEA ALLWISE ID, from TESS cross-match
(JHHMMSS.ss+DDMMSS.s)
21- 30 F10.4 pc Dist [26/33103] Distance from Gaia DR3 (geometric),
Gaia DR3
32- 39 F8.3 mas/yr pmRA [-217/215] Proper motion, in RA, Gaia DR3
41- 48 F8.3 mas/yr pmDE [-208/150] Proper motion, in DE, Gaia DR3
50- 72 E23.16 pc Z [-18.9/32.2] Distance (height) from
the Galactic disk
74- 92 F19.16 pc R [0.73/21.7] Radial distance away from the
Galactic center
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Global notes:
Note (G1): From the LAMOST Stellar Parameter pipeline, Luo+ (2015, V/146),
2019, V/164, Release DR10, as described at:
https://www.lamost.org/dr10/v1.0/doc/release-note.
Note (G2): As derived in Equation 1 (see Section 3).
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Acknowledgements:
Zhiruo Zhang [ourihzgnahz at qq dot com]
History:
From electronic version of the journal
* 10-Aug-2026: Insert into VizieR
* 24-Aug-2026: Table 1b added to identify objects without WISEA
identifiers from the original Table 1 (rows without identifier
in Table 1 have been removed)
License: CC-BY-4.0
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 16-Jun-2026