J/ApJS/281/65 Halpha emission-line stars from LAMOST MRS DR7 (Yu+, 2025)
A catalog of 45,206 Hα emission-line stars from LAMOST MRS DR7.
Yu L., Li J., Wang J., He T., Han Z.
<Astrophys. J. Suppl. Ser., 281, 65 (2025)>
=2025ApJS..281...65Y 2025ApJS..281...65Y
ADC_Keywords: Stars, emission; Spectra, optical; Line Profiles
Keywords: Catalogs ; Emission line stars ; Classification systems ;
Stellar spectral lines
Abstract:
Stars that exhibit prominent emission lines in their spectra are
referred to as emission-line stars, encompassing a wide range of
stellar types and indicative of intriguing physical properties. The
Large Sky Area Multi-Object fiber Spectroscopic Telescope (LAMOST) has
released millions of spectra from its Medium-Resolution Survey (MRS).
A small fraction of these spectra exhibit emission lines, yet they
remain undiscovered and unanalyzed due to being buried in the vast
dataset. We have developed a method based on derivative spectroscopy,
which provides a novel approach for detecting and identifying
emission-line stars by extracting signals from complex backgrounds and
estimating spectral line profiles. Applying this method to the
Hα spectral line profiles from the LAMOST-MRS Data Release 7, we
compiled a catalog of emission-line stars using the second- and
third-derivative spectra for automated peak detection. This approach
also facilitates the classification of Hα emission-line
morphologies through a simplified scheme. The catalog comprises
56,649 spectra with relatively prominent Hα emission lines from
45,206 unique stars, with each emission-line component accompanied by
approximate estimates of its wavelength, amplitude, and width. All
Hα spectral lines were classified into three morphological
classes under a unified classification scheme: single emission peak
(83.0%), double emission peaks (5.6%), and P Cygni-type profiles
(11.5%), which encompass both P Cygni and inverse P Cygni features.
Through cross-referencing with SIMBAD, 39,497 stars represent new
emission-line sources discovered in our research.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 275 56664 Catalogue of Hα emission line stars
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See also:
B/gcvs : General Catalogue of Variable Stars (Samus+, 2007-2017)
V/156 : LAMOST DR7 catalogs (Luo+, 2019)
V/162 : LAMOST DR11 catalogs (Luo+, 2026)
J/ApJS/94/687 : Old stellar populations. V. (Worthey+, 1994)
J/AJ/119/1901 : ROTSE all-sky surveys for variable stars (Akerlof+, 2000)
J/AJ/128/2965 : Red variables in the NSVS (Williams+, 2004)
J/ApJ/667/308 : Weak-line T Tauri in Spitzer c2d Survey. II. (Cieza+, 2007)
J/AJ/138/466 : NSVS variables automated classification (Hoffman+, 2009)
J/A+A/548/A79 : INTEGRAL-OMC opt. variable sources (Alfonso-Garzon+, 2012)
J/ApJ/756/27 : Classif. of sources from the 2XMMi-DR3 cat. (Lin+, 2012)
J/AJ/144/192 : Spitzer survey of Orion A and B. I. YSOs (Megeath+, 2012)
J/ApJ/773/54 : Var. stars in & around NGC2264 with BEST (Klagyivik+, 2013)
J/A+A/560/A4 : Rotation periods of active Kepler stars (Reinhold+, 2013)
J/other/IBVS/6106 : RR Lyrae stars in GCVS observed by the QES (Bramich+, 2014)
J/ApJS/213/9 : Catalina Surveys periodic variable stars (Drake+, 2014)
J/ApJS/213/34 : Veloc. of Cygnus OB2 massive binaries (Kobulnicky+, 2014)
J/ApJS/211/24 : Rotation periods of Kepler MS stars (McQuillan+, 2014)
J/A+A/579/A19 : K2 Variable Catalogue (Armstrong+, 2015)
J/AJ/149/7 : SDSS-III/APOGEE. I. Be stars (Chojnowski+, 2015)
J/AJ/150/97 : Rvel in M67. I. 1278 candidate members (Geller+, 2015)
J/A+A/581/A52 : Gaia-ESO Survey: Ha emission stars cat. (Traven+, 2015)
J/A+A/581/A66 : UV variability and accretion in NGC 2264 (Venuti+, 2015)
J/ApJ/823/114 : Cannon: a new approach to determine masses (Ness+, 2016)
J/ApJS/232/16 : Mira stars discovered in LAMOST DR4 (Yao+, 2017)
J/ApJS/236/27 : APOGEE-2 survey of Orion Complex (OSFC). I. (Cottle+, 2018)
J/AJ/156/241 : Variable stars measured by ATLAS (Heinze+, 2018)
J/ApJ/868/70 : Hot subdwarf stars from Gaia DR2 & LAMOST DR5 (Lei+, 2018)
J/AJ/157/196 : Close companions around young stars (Kounkel+, 2019)
J/MNRAS/487/3505 : Variable stars in NGC 2244 (Michalska, 2019)
J/ApJ/872/137 : Abund. of red clump & RGB with APOGEE (Shetrone+, 2019)
J/ApJS/249/18 : The ZTF catalog of periodic variable stars (Chen+, 2020)
J/A+A/639/A63 : Active red giants asteroseismic & rot. (Gaulme+, 2020)
J/A+A/643/A122 : Active deep learning in large sp. surveys (Skoda+, 2020)
J/A+A/638/A21 : Herbig Ae/Be & classical Be stars catalog (Vioque+, 2020)
J/ApJS/246/9 : Stellar param. of LAMOST stars using SLAM (Zhang+, 2020)
J/MNRAS/495/1252 : Magnetic activity based on LAMOST and Kepler (Zhang+, 2020)
J/MNRAS/501/5927 : New classical Ae stars using LAMOST DR5 (Anusha+, 2021)
J/MNRAS/500/4849 : GALAH emission-line stars (Cotar+, 2021)
J/other/RAA/21.288 : Hot emission-line stars in LAMOST DR5 (Shridharan+, 2021)
J/ApJ/937/110 : B-type stars abund. from LAMOST DR5 LRS sp. (Liu+, 2022)
J/ApJS/260/35 : Classical Be stars from LAMOST MRS DR7 (Wang+, 2022)
J/ApJS/259/38 : Ha em.-line stars & Herbig Ae/Be from LAMOST (Zhang+, 2022)
J/ApJS/267/5 : S-type stars from LAMOST MRS DR10 spectra (Chen+, 2023)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- --- [LAMOST]
8- 26 A19 --- LAMOST LAMOST designation (JHHMMSS.ss+DDMMSS.s)
28- 57 A30 --- OName Source ID from SIMBAD
59- 68 F10.6 deg RAdeg Right ascension (J2000)
70- 78 F9.6 deg DEdeg [-10/79] Declination (J2000)
80- 124 A45 --- FileName FITS file name of LAMOST-MRS
126- 128 A3 --- Flags Morphological categories of Hα lines (1)
130- 152 A23 --- Type Object classification reported in literature
154 A1 --- HII Projected on HII regions? Y=Yes, N=No
156 A1 --- [NII] Presence of [NII] emission? Y=Yes, N=No
158- 163 F6.1 0.1nm lamB [6548/6552]? Central wavelength of [NII] line
at blue side; Angstroms
165- 170 F6.1 0.1nm lamR [6583/6587]? Central wavelength of [NII] line
at red side; Angstroms
172- 179 F8.3 0.1nm lam1 [6558.6/6571]? Central wavelength of first
peak; Angstroms
181- 188 F8.3 0.1nm lam2 [6559/6571]? Central wavelength of second
peak; Angstroms
190- 197 F8.3 0.1nm lam3 [6561.8/6571]? Central wavelength of third
peak; Angstroms
199- 206 F8.3 0.1nm lam4 [6564.2/6571]? Central wavelength of fourth
peak; Angstroms
208- 213 F6.4 0.1nm lamErr [0.0016/0.5]? Statistical error of central
wavelength; Angstroms
215- 220 F6.2 --- Amp1 [0/279.5]? Amplitude of first peak
222- 226 F5.2 --- Amp2 [0.05/50.1]? Amplitude of second peak
228- 231 F4.2 --- Amp3 [0.05/1.3]? Amplitude of third peak
233- 236 F4.2 --- Amp4 [0.28/0.93]? Amplitude of fourth peak
238- 242 F5.3 --- AmpErr [0.04/0.3]? Statistical error of amplitude
244- 247 F4.2 0.1nm w1 [0.3/5.6]? Width of first peak; Angstroms
249- 252 F4.2 0.1nm w2 [0.3/4.7]? Width of second peak; Angstroms
254- 257 F4.2 0.1nm w3 [0.3/5.8]? Width of third peak; Angstroms
259- 262 F4.2 0.1nm w4 [0.9/2.9]? Width of fourth peak; Angstroms
264- 268 F5.3 0.1nm wErr [0.04/0.54]? Statistical error of width;
Angstroms
270- 275 F6.2 --- SNR [0/999]? Signal-to-noise ratio
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Note (1): In this study, we catalog the Halpha emission lines detected by
derivative spectroscopy (DS) in the LAMOST Medium-Resolution Survey
(MRS) DR7 dataset and classify them into six common categories as follows:
1E = single emission without absorption (15370 occurrences)
1EA = single emission with absorption (31627 occurrences)
2E = double emissions without absorption (3015 occurrences)
2EA = double emissions with absorption (102 occurrences)
PC = P Cygni profiles (4180 occurrences)
IPC = inverse P Cygni profiles (2355 occurrences)
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History:
From electronic version of the journal
License: CC-BY-4.0
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 30-Jun-2026