J/ApJS/279/40 Carbon star candidates from LAMOST and SDSS (Zhou+, 2025)
Identifying carbon star candidates from LAMOST DR11 and SDSS DR18 based on a
parallel feature recognition method.
Zhou L., Cai J., Yang H., Luo A., Li Y., Shi C., Zhang B., Tian J.,
Yuan Y., Yang Y.
<Astrophys. J. Suppl. Ser., 279, 40 (2025)>
=2025ApJS..279...40Z 2025ApJS..279...40Z
ADC_Keywords: Stars, carbon; Spectra, optical; Redshifts; Magnitudes, absolute;
Infrared sources
Keywords: Carbon stars ; Catalogs ; Astrostatistics ; Distributed computing
Abstract:
Carbon stars are critical for understanding stellar evolution and
exploring cosmic chemistry. This paper provides 7809 carbon star
candidates identified from the Large-Area Multi-Object Fiber Optic
Spectroscopic Telescope (LAMOST) DR11 and Sloan Digital Sky Survey
(SDSS) DR18, using a parallel carbon star feature recognition method.
This method deploys a parallel multi-interval feature representation
model and a k-nearest neighbor classification model, effectively
characterizing local and global molecular bands of carbon stars and
enhancing feature discrimination, especially for weak features that
are highly susceptible to noise interference. The recognition
performance F1-score can exceed 96%. Moreover, with parallel
strategies for interval representation, the search efficiency has
improved. And we construct a new catalog of carbon stars subtypes,
including 1616 barium (Ba) stars, 1720 C-H stars, 1621 C-N stars,
1205 C-R stars, and 1647 stars labeled as "Unknown" due to their low
signal-to-noise ratios (S/Ns). Compared with the LAMOST DR11 pipeline,
carbon stars by Li+ 2024, J/ApJS/271/12 and the SDSS DR18 pipeline, we
identify 1403 and 1644 new candidates from LAMOST, and 661 new
candidates from SDSS DR18, respectively. In our catalog, the majority
of C-N, C-R, and Ba stars from LAMOST are located at low Galactic
latitudes with |b|=30°, while most candidates from SDSS are
located at high Galactic latitudes. And the vast majority of Ba, C-H,
C-R, and Unknown stars show relatively high effective temperatures.
Some carbon stars exhibit stellar activity, potentially influenced by
dense interstellar materials, internal magnetic fields, and rotation
effects. In the g, r, and i bands, C-N and Unknown stars from LAMOST
exhibit lower S/Ns, influenced by high interstellar density at low
Galactic latitudes, while Unknown stars from SDSS show higher S/Ns.
Among the newly discovered carbon stars, Ba from LAMOST, Unknown from
SDSS, and C-R stars have higher S/Ns than other subclasses.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 236 7809 Information of carbon stars identified from LAMOST
LRS DR11 v1.0 and SDSS DR18
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See also:
III/156 : Cool Galactic Carbon Stars, 2nd Edition (Stephenson 1989)
III/227 : General Catalog of galactic Carbon stars, 3d Ed. (Alksnis+ 2001)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
V/162 : LAMOST DR11 catalogs (Luo+, 2026)
J/ApJS/105/419 : Spectral Atlas of Carbon Stars (Barnbaum+ 1996)
J/A+A/375/366 : Carbon stars from the Hamburg/ESO survey (Christlieb+ 2001)
J/AJ/124/1651 : Faint high-lat. carbon stars SDSS photometry (Margon+, 2002)
J/AJ/127/2838 : Faint high-lat. carbon stars SDSS photometry (Downes+, 2004)
J/A+A/473/143 : Radial velocities of C stars near Gal. plane (Demers+, 2007)
J/ApJ/765/12 : Carbon stars & DQ white dwarfs from SDSS (Green, 2013)
J/other/SCPMA/57.176 : Carbon stars & DZ white dwarfs in SDSS sp. (Si+ 2014)
J/other/RAA/15.1671 : New carbon stars from LAMOST survey (Si+, 2015)
J/MNRAS/459/4299 : Barium stars abundances and kinematics (de Castro+, 2016)
J/ApJS/226/1 : Carbon stars from LAMOST DR2 data (Ji+, 2016)
J/ApJS/232/16 : Mira stars discovered in LAMOST DR4 (Yao+, 2017)
J/ApJS/234/31 : Carbon stars from LAMOST using machine learning (Li+, 2018)
J/AJ/156/112 : NIR Mira period-luminosity relations in M33 (Yuan+, 2018)
J/MNRAS/495/2858 : Carbon stars as standard candles. I. (Ripoche+, 2020)
J/ApJS/272/6 : CaII triplet stellar-activity indices (Huang+, 2024)
J/ApJS/271/12 : Carbon stars from LAMOST DR7 (Li+, 2024)
J/ApJS/272/43 : Am and Ap star candidates from LAMOST DR10 (Yang+, 2024)
http://www.lamost.org/dr11/v1.0/ : LAMOST DR11 homepage
http://www.sdss.org/dr18/ : SDSS DR18 homepage
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [1/7809] Sequential identifier
6- 25 A20 --- ObsID LAMOST DR11 v1 obsid or SDSS DR18 SPECOBJID
27- 38 F12.8 deg RAdeg Right Ascension (J2000) (1)
40- 48 F9.5 deg DEdeg [-18.7/84.2] Declination (J2000) (1)
50- 55 A6 --- n_ObsID LAMOST LRS DR11 or SDSS DR8 catalog identifier
57- 75 A19 --- Name LAMOST or SDSS name (JHHMMSS.ss+DDMMSS.s) (1)
76 A1 --- f_Name [*] *: target identified from both LAMOST and
SDSS
78- 81 A4 --- Class Class from LAMOST/SDSS (Always "STAR")
83- 100 A18 --- subClass Subclass (1)
102- 112 F11.5 --- zspec [-0.005/0.7]?=-9999 LAMOST spectroscopic
redshift
114- 121 F8.2 --- snrg [-10.2/454]?=-9999 Signal-to-Noise ratio
in g (1)
123- 130 F8.2 --- snrr [-8.5/812]?=-9999 Signal-to-Noise ratio
in r (1)
132- 137 F6.2 --- snri [-8.7/999] Signal-to-Noise ratio in i (1)
139- 145 A7 --- subType Spectral subtype, derived in this work
147 I1 --- new [0/1] 1=new discovered carbon stars
(1604 occurrences)
149- 164 A16 --- Activity Stellar activity types (2)
166- 167 A2 --- Mira Flags for mira variable stars (3)
169- 171 A3 --- Qfl 2MASS Qfl quality flag (4)
173- 179 F7.4 mas plx [-1.22/23.9]? Parallax (4)
181- 186 F6.4 mas e_plx [0.01/0.5]? Uncertainty in plx (4)
188- 194 F7.2 K Teff [3279/9575]? Surface effective temperature
(teff_val) (4)
196- 201 F6.2 mag GMag [-16.7/14.4]? Absolute Gaia DR2 G magnitude (4)
203- 208 F6.2 mag BPMag [-15.91/14.24]? Absolute Gaia DR2 BP
magnitude (4)
210- 215 F6.2 mag RPMag [-17.5/13.7]? Absolute Gaia DR2 RP magnitude
(4)
217- 222 F6.2 mag JMag [-18.54/13.51]? Absolute 2MASS J magnitude (4)
224- 229 F6.2 mag HMag [-19.17/12.74]? Absolute 2MASS H magnitude (4)
231- 236 F6.2 mag KsMag [-19.4/13.63]? Absolute 2MASS Ks magnitude (4)
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Note (1): Values taken from LAMOST DR11 or SDSS DR18.
Note (2): The value "0" in the stellar activity column indicates
that the target spectrum does not display emission lines or
stellar activity.
Note (3): Code as follows:
1 = Mira variable (24 occurrences)
1* = this Mira target has light curves from the Zwicky Transient Facility
(ZTF; https://irsa.ipac.caltech.edu/Missions/ztf.html) and
ASAS-SN (https://asas-sn.osu.edu/variables); 8 occurrences
Note (4): From Gaia DR2. The interstellar dust extinction and redden
are corrected by Geometric distances from Bailer-Jones+ (2021, I/352),
E(B-V) values of Green+ 2019ApJ...887...93G 2019ApJ...887...93G and the extinction
coefficient of Wang & Chen 2019ApJ...877..116W 2019ApJ...877..116W.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 24-Feb-2026