J/AJ/169/266 Estimated magnitudes & distances of LAMOST DR10 stars (Yang+, 2025)
A catalog of distance determinations for 5 million stars in LAMOST DR10.
Yang C., Xue X.-X., Liu C., Tian H., Zhu L., Zhang L.
<Astron. J., 169, 266 (2025)>
=2025AJ....169..266Y 2025AJ....169..266Y
ADC_Keywords: Stars, distances; Photometry; Optical; Infrared; Spectra, optical;
Surveys
Keywords: Stellar distance ; Surveys ; Milky Way stellar halo ; Milky Way Galaxy
Abstract:
Using the distance estimation method outlined in J. L. Carlin et al.,
a Bayesian approach specifically tailored for LAMOST data, we
estimated distances for 7,450,303 spectra from 5,394,174 unique stars
in the LAMOST DR10 low-resolution data set. To accommodate the
significant increase in data volume and quality in LAMOST DR10,
several improvements were applied to the method in J. L. Carlin et al.:
utilizing denser isochrones, increasing the density of interpolated
isochrone grids, and incorporating Gaia G-band magnitudes alongside
Two Micron All Sky Survey K-band magnitudes for more comprehensive
distance estimates. A comparison with Gaia parallaxes shows good
consistency across the data. For parallaxes below 1mas, the estimated
distances are underestimated by 4% for the K band and 10% for the G
band, while for parallaxes below 0.25mas, the distances are
overestimated by 9% for the K band and 7% for the G band. Distance
uncertainties initially increase with distance, with relative distance
uncertainties starting at 5% at 1kpc and rising to 17% at 20kpc, then
decreasing to 10%-15% for distances greater than 50kpc. The number of
stars with distances between 5 and 10kpc is ∼1.8x105, and ∼6x104
for distances greater than 10kpc.
Description:
LAMOST, operated by the National Astronomical Observatories of the
Chinese Academy of Sciences, is a reflecting Schmidt telescope
equipped with 4000 fibers and a 20deg2 field of view. The LAMOST
DR10 Version 2.0 contains observational data comprising over 10
million spectra collected between 2011 October 24 and 2022 June 2.
This release includes 11,441,011 low-resolution spectra, of which
7,450,303 spectra from 5,394,174 unique stars (deduplicated by unique
source identifier) provide detailed atmospheric parameters along with
associated uncertainties. The data used in this work are accessible
through the LAMOST online database, specifically the LAMOST
Low-Resolution Spectroscopic Survey (LRS) Stellar Parameter Catalog of
A, F, G, and K Stars.
The observed atmospheric parameters from LAMOST DR10 (Teff, log(g),
and [Fe/H], along with their associated uncertainties) are used as
inputs for distance estimation. We compare them with interpolated
isochrone grids derived from MIST isochrones (Choi+, 2016ApJ...823..102C 2016ApJ...823..102C)
to obtain posterior probability distributions for the absolute
magnitudes of stars. We use magnitudes in the Ks band from the Two
Micron All Sky Survey (II/246) and in the G band from Gaia (DR3; I/355),
both of which cover ∼98% of the LAMOST data. The distances of LAMOST
DR10 stars are derived using the distance modulus by comparing the
estimated absolute magnitudes with the extinction-corrected
photometric magnitudes.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
target.dat 117 7450303 *List of observations from LAMOST DR10 (table added
by CDS)
table2.dat 146 7450303 Catalog of 7,450,303 spectra from LAMOST DR10
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Note on target.dat: This table contains selected columns from the "LAMOST Low
Resolution Spectra Stellar Parameter Catalogue of A, F, G and K Stars".
The data was downloaded directly from the LAMOST DR10 v2.0 database
(http://www.lamost.org/dr10/v2.0/catalogue)
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)
II/389 : The Pan-STARRS release 1 (PS1) Survey - DR2 (Magnier+, 2025)
V/162 : LAMOST DR11 catalogs (Luo+, 2026)
J/other/RAA/11.924 : Atmospheric parameters for 771 stars (Wu+, 2011)
J/ApJ/880/65 : LAMOST K giants in Galactic halo substructures (Yang+, 2019)
J/A+A/640/A127 : Open cluster properties with Gaia and LAMOST (Zhong+, 2020)
J/ApJS/247/9 : FGK stars magnetic activ. in LAMOST-Kepler field (Zhang+, 2020)
J/ApJS/247/28 : K2 star parameters from Gaia & LAMOST (Hardegree-Ullman+, 2020)
J/ApJ/910/46 : Galactic anticenter substructure stars from LAMOST (Li+, 2021)
J/ApJS/266/14 : Am stars selected in LAMOST DR8-DR10 (Tian+, 2023)
J/ApJS/267/5 : S-type stars from LAMOST MRS DR10 spectra (Chen+, 2023)
J/AJ/165/224 : Distance determinations for LAMOST DR8 K-giants (Zhang+, 2023)
J/ApJS/271/60 : Magnetic activ. of G-type stars from LAMOST & TESS (Su+, 2024)
J/ApJS/272/43 : Am and Ap star candidates from LAMOST DR10 (Yang+, 2024)
http://www.lamost.org/dr10/catalogue : LAMOST DR10 v2.0 database
Byte-by-byte Description of file:target.dat
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Bytes Format Units Label Explanations
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1- 10 I10 --- ObsID [101001/1018116242] Unique identifier for
the LAMOST spectrum (obsid)
12- 30 A19 --- Target Target designation, JHHMMSS.ss+DDMMSS.s
(designation)
32- 41 A10 "Y/M/D" Obs.Date Target observation date (obsdate)
43- 56 F14.10 deg RAdeg Fiber pointing right Aacension (J2000)
(ra_obs)
58- 70 F13.10 deg DEdeg Fiber pointing declination (J2000)
(dec_obs)
72- 75 A4 --- Class [STAR] Spectral type (class)
77- 78 A2 --- subClass Stellar spectral type (subclass) (1)
80- 97 I18 --- PanSTARRS ? Pan-STARRS (II/349) identifier (ps_id)
99- 117 I19 --- GaiaDR3 ? Gaia DR3 (I/355) source ID
(gaia_source_id)
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Note (1): Spectral type occurrences as follows:
A0 = 1197 occurrences
A1 = 101455 occurrences
A2 = 56618 occurrences
A3 = 13219 occurrences
A5 = 71933 occurrences
A6 = 52677 occurrences
A7 = 97168 occurrences
A8 = 4937 occurrences
A9 = 12803 occurrences
F0 = 464532 occurrences
F2 = 222603 occurrences
F3 = 54309 occurrences
F4 = 44520 occurrences
F5 = 482414 occurrences
F6 = 172231 occurrences
F7 = 246010 occurrences
F8 = 61790 occurrences
F9 = 407238 occurrences
G0 = 252589 occurrences
G1 = 79699 occurrences
G2 = 492963 occurrences
G3 = 646679 occurrences
G4 = 165672 occurrences
G5 = 818791 occurrences
G6 = 162239 occurrences
G7 = 415552 occurrences
G8 = 356188 occurrences
G9 = 158402 occurrences
K0 = 100430 occurrences
K1 = 221770 occurrences
K2 = 15330 occurrences
K3 = 279458 occurrences
K4 = 107391 occurrences
K5 = 383055 occurrences
K7 = 226441 occurrences
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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- 10 I10 --- ObsID [101001/1018116242] Unique identifier for
the LAMOST DR10 spectrum (1)
12- 16 F5.2 mag Ksmag [3.16/17.64]? Observed magnitude in the
2MASS Ks band (2)
18- 22 F5.2 mag Gmag [5.68/21.03]? Observed magnitude in the Gaia
DR3 G band (3)
24- 28 F5.2 mag E(B-V) [0.0/50.71] Color excess
(Schlegel+, 1998ApJ...500..525S 1998ApJ...500..525S)
30- 34 F5.2 mag AKs [0.0/14.2] Extinction in 2MASS Ks band (4)
36- 41 F6.2 mag AG [0.01/138.94] Extinction in Gaia G band (4)
43- 47 F5.2 mag Ksmag0 [-3.33/17.64]? Extinction-corrected
photometric magnitude in the 2MASS Ks band
49- 55 F7.2 mag Gmag0 [-124.61/20.93]? Extinction-corrected
photometric magnitude in the Gaia G-band
57- 61 F5.2 mag KsMag-16 [-8.0/6.13] 16th percentile of the
cumulative PDF for KsMag (5)
63- 67 F5.2 mag KsMag-50 [-8.0/6.18] 50th percentile of the
cumulative PDF for KsMag (5)
69- 73 F5.2 mag KsMag-84 [-8.0/6.25] 84th percentile of the
cumulative PDF for KsMag (5)
75- 79 F5.2 mag GMag-16 [-4.0/9.15] 16th percentile of the
cumulative PDF for GMag (5)
81- 85 F5.2 mag GMag-50 [-4.0/9.27] 50th percentile of the
cumulative PDF for GMag (5)
87- 91 F5.2 mag GMag-84 [-4.0/9.7] 84th percentile of the cumulative
PDF for GMag (5)
93- 98 F6.2 kpc DistKs-16 [0.05/285.52]? Distance derived from
KsMag-84 and Kmag0 (6)
100- 105 F6.2 kpc DistKs-50 [0.05/295.14]? Distance derived from
KsMag-50 and Kmag0 (6)
107- 113 F7.2 kpc DistKs-84 [0.05/1050.42]? Distance derived from
KsMag-84 and Kmag0 (6)
115- 119 F5.2 kpc errDistKs [0.0/71.99]? Distance uncertainty,
calculated as (DistKs84-DistKs16)/2
121- 126 F6.2 kpc DistG-16 [0.05/191.55]? Distance derived from GMag-84
and Gmag0 (6)
128- 133 F6.2 kpc DistG-50 [0.05/235.66]? Distance derived from GMag-50
and Gmag0 (6)
135- 140 F6.2 kpc DistG-84 [0.05/709.1]? Distance derived from GMag-16
and Gmag0 (6)
142- 146 F5.2 kpc errDistG [0.0/49.68]? Distance uncertainty,
calculated as (DistG84-DistG16)/2
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Note (1): Stellar atmospheric parameters were obtained from the
LAMOST DR10 v2.0 catalog of AFGK-type stars (available at
http://www.lamost.org/dr10/catalogue).
Note (2): 2MASS (II/246) K-band magnitudes were obtained by cross-matching the
LAMOST-provided Gaia DR3 (I/355) source_id with Gaia DR3's
tmass_psc_xsc_best_neighbor table, with unmatched sources left empty.
Note (3): Gaia DR3 G-band magnitudes were obtained by cross-matching
the LAMOST-provided Gaia DR3 (I/355) source_id with the Gaia DR3 catalog,
with unmatched sources left empty.
Note (4): The extinction in the Ks band is given by AKs=0.28E(B-V)
(Majewski+, 2003ApJ...599.1082M 2003ApJ...599.1082M), and the extinction correction in
the G band is given by AG=2.74E(B-V) (Casagrande+, 2018MNRAS.479L.102C 2018MNRAS.479L.102C).
Note (5): The median of the cumulative probability density function, or
50th percentile (KsMag-50 & GMag-50), is considered the best estimate of
the absolute magnitude, while the uncertainties are determined from the
16th percentile (KsMag-16 & GMag-16) and 84th percentile (KsMag-84 &
GMag-84) values, representing the lower and upper limits, respectively.
Note (6): The distance percentiles Dist16 and Dist84 correspond to the
Mag-84 and Mag-16 percentiles, respectively, following the convention
that ensures Dist-84 > Dist-16.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Robin Leichtnam [CDS] 26-Jan-2026