I/370 SPDist: stellar distance catalog from DESI DR1 (DESI+, 2026)
SPDist. Value added distance catalog for stars from DESI Year-1 data.
DESI Collaboration et al.
=2026yCat.1370....0D 2026yCat.1370....0D
ADC_Keywords: Photometry, ugriz; Stars, distances; Surveys; Spectra, optical;
Milky Way; Parallaxes, trigonometric
Keywords: Astronomy data analysis ; Stellar distance ; Redshift surveys
Abstract:
This catalog provides spectrophotometric distances in the form of
absolute magnitude in the Gaia G-band for all stars observed by the
DESI MWS, using a data-driven approach similar to Thomas & Battaglia
(2022). Distances are estimated using a fully connected multi-layer
perceptron (MLP) model using Gaia DR3 photometry (Gaia Collaboration
et al. 2023), spectroscopic metallicity from the SP pipeline, and
atmospheric parameters (effective temperature and surface gravity)
derived from a combination of values from both the RV and SP pipelines
(Koposov et al. 2024) as inputs. The table here is row-matched to DESI
MWS Iron release. Note that SPdist stands for Spectro-photometric
distances and is not related to the SP pipeline used in the MWS Value
Added Catalog.
Description:
The Dark Energy Spectroscopic Instrument (DESI) is one of the foremost
multiobject spectrographs operating at Kitt Peak National Observatory
in Arizona, USA. It observes the rest-frame wavelength range of
3600-9824Å with spectral resolution R∼2500-5000.
We use the Milky Way Survey (MWS) data from DR1 (V/161), which covers
DESI Year-1 observations (observed from 2021 May through 2022 June).
Our stellar distance catalog (SPDist) is published as one of the Value
Added Catalogs (VACs) accompanying DESI DR1. It provides spectrophotometric
distances in the form of absolute magnitude in the Gaia G-band for all
stars observed by the DESI MWS, using a data-driven approach similar
to Thomas+2022 (J/A+A/660/A29). Distances are estimated using a fully
connected multi-layer perceptron (MLP) model using Gaia DR3 (I/355)
photometry, spectroscopic metallicity from the SP pipeline, and
atmospheric parameters (effective temperature and surface gravity)
derived from a combination of values from both the RV and SP pipelines
(Koposov+2024, 2024MNRAS.533.1012K 2024MNRAS.533.1012K) as inputs.
The DESI MWS provides two stellar distance VACs: SpecDis (this
catalog) and SPDist. The major difference between these two catalogs
lies in the method used to derive the distances. SpecDis predicts
distances directly from stellar spectra, while SPdist uses the stellar
parameters provided by the DESI MWS pipelines.
This catalog presents the spectrophotometric distances for all stars
observed by the MWS predicted using a multi-layer perceptron trained
on a selection of stellar parameters.
Acknowledgements:
This research used data obtained with the Dark Energy Spectroscopic
Instrument (DESI). DESI construction and operations is managed by the
Lawrence Berkeley National Laboratory. This material is based upon
work supported by the U.S. Department of Energy, Office of Science,
Office of High-Energy Physics, under Contract No. DE-AC02-05CH11231,
and by the National Energy Research Scientific Computing Center, a DOE
Office of Science User Facility under the same contract. Additional
support for DESI was provided by the U.S. National Science Foundation
(NSF), Division of Astronomical Sciences under Contract No. AST-0950945
to the NSF's National Optical-Infrared Astronomy Research Laboratory;
the Science and Technology Facilities Council of the United Kingdom;
the Gordon and Betty Moore Foundation; the Heising-Simons Foundation;
the French Alternative Energies and Atomic Energy Commission (CEA);
the National Council of Humanities, Science and Technology of Mexico
(CONAHCYT); the Ministry of Science and Innovation of Spain (MICINN),
and by the DESI Member Institutions:
http://www.desi.lbl.gov/collaborating-institutions. The DESI
collaboration is honored to be permitted to conduct scientific
research on I'oligam Du'ag (Kitt Peak), a mountain with particular
significance to the Tohono O'odham Nation. Any opinions, findings, and
conclusions or recommendations expressed in this material are those of
the author(s) and do not necessarily reflect the views of the U.S.
National Science Foundation, the U.S. Department of Energy, or any of
the listed funding agencies.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
spdist.dat 574 5069738 *Milky Way Survey (MWS) SPDist catalog from DESI DR1
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Note on spdist.dat: The original table is row-matched to DESI MWS Iron release.
Rows without data have been removed from the VizieR version of the SPDist
catalog, but the columns CatID and RefID give the matching rows in the
MWS Iron catalog.
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
I/354 : StarHorse2, Gaia EDR3 photo-astrometric distances (Anders+, 2022)
V/161 : DESI DR1 redshift catalog (DESI Col.+ 2025)
J/ApJ/621/673 : Line indices for 124 early-type galaxies (Thomas+, 2005)
J/MNRAS/398/1757 : RR Lyraes in SDSS stripe 82 (Watkins+, 2009)
J/AJ/140/184 : RAVE double-lined spectroscopic binaries (Matijevic+, 2010)
J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)
J/AJ/141/115 : BV(RI)c photometry on NGC 3532 (Clem+, 2011)
J/ApJ/736/146 : Radial velocities of stars in Bootes I (Koposov+, 2011)
J/ApJ/784/170 : The SEGUE K giant survey. II. Dist. of 6036 stars (Xue+, 2014)
J/ApJ/850/96 : PS1 3π RRab stars within the Sgr stream (Hernitschek+, 2017)
J/A+A/608/A95 : GES: multi-line spectroscopic binary candidates (Merle+, 2017)
J/AJ/156/18 : APOGEE DR14:Binary comp. of evolved stars (Price-Whelan+, 2018)
J/A+A/622/A60 : Gaia DR2 misclassified RR Lyrae list (Clementini+, 2019)
J/AJ/158/147 : Spectrophotometric parallaxes with linear models (Hogg+, 2019)
J/ApJ/879/69 : The Payne applied to the APOGEE DR14 data set (Ting+, 2019)
J/ApJS/245/34 : Abundances for 6 million stars from LAMOST DR5 (Xiang+, 2019)
J/A+A/638/A76 : StarHorse data for 5 surveys (Queiroz+, 2020)
J/AJ/162/184 : APOGEE: Properties & RVs of binaries (Kounkel+, 2021)
J/MNRAS/501/2279 : Stars in the Sagittarius stream (Vasiliev+, 2021)
J/ApJS/253/22 : Ks absolute mag. from LAMOST for OB stars (Xiang+, 2021)
J/A+A/662/A66 : Hot stars from LAMOST DR6 (Xiang+, 2022)
J/ApJS/258/26 : Spectroscopic binaries from LAMOST MRS. I. (Zhang+, 2022)
J/ApJS/273/19 : Elemental abundances from DESI EDR spectra (Zhang+, 2024)
J/AJ/169/266 : Estimated mag. & distances of LAMOST DR10 stars (Yang+, 2025)
J/AJ/170/171 : SpecDis v2.1: Stellar distance catalog from DESI DR1 (Li+, 2025)
http://data.desi.lbl.gov/public/dr1/vac/dr1/mws-spdist : MWS SPDist
Byte-by-byte Description of file: spdist.dat
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Bytes Format Units Label Explanations
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1- 7 I7 --- CatID [1/6272510] Entry ID, matching the main
DESI MWS Iron catalog (CAT_ID)
9- 27 I19 --- RefID Reference ID from the DESI MWS Iron
catalog (REF_ID)
29- 47 I19 --- TargetID ID of the target (TARGETID)
49- 67 I19 --- GaiaDR3 Gaia DR3 identifier (SOURCE_ID)
69- 73 A5 --- fGood True if the TEFF and LOGG parameters
estimated by SP and RVS pipelines are
within 3-sigma of the median distribution
(FLAG_GOOD)
75- 93 F19.13 K Teff-cor [2399.95/22549.5]? Average temperature of
the SP and RVS pipeline, calibrated on the
RVS base (TEFF_COR)
95- 116 E22.19 --- logg-cor [-0.5/6.5]? Average SP and RVS logg
(LOGG_COR)
118- 138 F21.19 mag GmagErr [2.75e-3/0.16]? Gaia G band uncertainties
(E_Gmag)
140- 160 F21.19 mag BPmagErr [2.75e-3/4.75]? Gaia BP band uncertainties
(E_BPmag)
162- 182 F21.19 mag RPmagErr [2.75e-3/6.34]? Gaia RP band uncertainties
(E_RPmag)
184- 201 F18.15 mag Gmag-dered [7.08/22.38]? Dereddened Gaia G band
photometry, using i the Schlegel+1998
(1998ApJ...500..525S 1998ApJ...500..525S) extinction map (G_0)
203- 220 F18.15 mag BPmag-dered [6.29/24.5]? Dereddened Gaia BP band
photometry (BP0)
222- 239 F18.15 mag RPmag-dered [7.65/23.95]? Dereddened Gaia RP band
photometry (RP0)
241- 253 E13.10 mag Mag [-9.41/19.73]? Absolute Magnitude using
the peak value of TEFF (RV & SP),
LOGG(RV&SP), FEH (SP), BP0 and RP0
(MG_PEAK)
255- 268 E14.10 mag Mag-5 [-7189.96/17.09]? 5th percentile of the
absolute magnitude distribution after the
propagation of the uncertainties on the
TEFF (RV & SP), LOGG(RV&SP), FEH (SP), BP
and RP (MG_5)
270- 283 E14.10 mag Mag-16 [-5111.99/104.14]? 16th percentile of the
absolute magnitude distribution after the
propagation of the uncertainties on the
TEFF (RV & SP), LOGG(RV&SP), FEH (SP), BP
and RP (MG_16)
285- 298 E14.10 mag Mag-50 [-421.4/4951.63]? Median of the absolute
magnitude distribution after the
propagation of the uncertainties on the
TEFF (RV & SP), LOGG(RV&SP), FEH (SP), BP
and RP; Recommanded value to use (MG_50)
300- 312 E13.10 mag Mag-84 [-50.08/15680.73]? 84th percentile of the
absolute magnitude distribution after the
propagation of the uncertainties on the
TEFF (RV & SP), LOGG(RV&SP), FEH (SP), BP
and RP (MG_84)
314- 326 E13.10 mag Mag-95 [-11.72/37833.6]? 95th percentile of the
absolute magnitude distribution after the
propagation of the uncertainties on the
TEFF (RV & SP), LOGG(RV&SP), FEH (SP), BP
and RP (MG_95)
328- 332 A5 --- fQual True if the parameters space are located
inside the region define by the training
sample (QFLAG_INPUT)
334- 574 A241 --- n_fQual Say the reason why the Qflag_input is
False (QFLAG_COMMENTS)
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History:
From electronic version of the journal
License:
The Dark Energy Spectroscopic Instrument (DESI) data are licensed
under the Creative Commons Attribution 4.0 International License
("CC BY 4.0", [Summary](http://creativecommons.org/licenses/by/4.0/),
[Full Legal Code](http://creativecommons.org/licenses/by/4.0/legalcode)).
Users are free to share, copy, redistribute, adapt, transform and
build upon the DESI data available through this website for any
purpose, including commercially.
(End) Prepared by Robin Leichtnam [CDS] 30-Sep-2026