Information on Service 'The Gaia eDR3 Catalogue of Nearby Stars GCNS'

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This is a clean and well characterised catalogue of objects within 100pc of the Sun from the Gaia early third data release. We characterise the catalogue using the full data release, and comparisons to other catalogues in literature and simulations. For all candidates (measured parallax < 8 mas), we calculate a distance probability function using Bayesian procedures and mock catalogues for the prediction of the priors. For each entry using a random forest classifier we attempt to remove sources with spurious astrometric solutions.

This results in 331312 objects that should contain at least 92% of stars within 100 pc at spectral type M9.

GCNS comes with several auxiliary tables, in particular lists of resolved stellar systems, of known neary stars not found in eDR3 and of candidates of Hyades and ComaBer cluster members.

For a list of all services and tables belonging to this service's resource, see Information on resource 'The Gaia eDR3 Catalogue of Nearby Stars GCNS'

Overview

You can access this service using:

This service is published as follows:

local means it is listed on our front page, ivo_managed means it has a record in the VO registry.

Spatial Coverage

Input Fields

The following fields are available to provide input to the service (with some renderers, some of these fields may be unavailable):

NameTable Head DescriptionUnitUCD
DEC Delta (ICRS) Declination (ICRS decimal) deg pos.eq.dec
dist_50 Dist50 Median of the distance PDF kpc stat.median;pos.distance
hscs_pos Position/Name Coordinates (as h m s, d m s or decimal degrees), or SIMBAD-resolvable object N/A N/A
hscs_sr Search radius Search radius in arcminutes N/A N/A
MAXREC Match limit Maximum number of records returned. Pass 0 to retrieve service parameters. N/A N/A
parallax Parallax Absolute barycentric stellar parallax of the source at the reference epoch J2016.0. If looking for a distance, consider joining with gedr3dist.main and using the distances from there. mas pos.parallax
RA Alpha (ICRS) Right Ascension (ICRS decimal) deg pos.eq.ra
RESPONSEFORMAT Output Format File format requested for output. N/A meta.code.mime
SR Search Radius Search radius deg N/A
VERB Verbosity Exhaustiveness of column selection. VERB=1 only returns the most important columns, VERB=2 selects the columns deemed useful to the average user, VERB=3 returns a table with all available columns. N/A N/A
xcoord_50 X Median x coordinate in the Galactic frame assuming dist_50 pc stat.median;pos.cartesian.x
ycoord_50 Y Median y coordinate in the Galactic frame assuming dist_50 pc stat.median;pos.cartesian.y
zcoord_50 Z Median z coordinate in the Galactic frame assuming dist_50 pc stat.median;pos.cartesian.z

Default Output Fields

The following fields are contained in the output by default. More fields may be available for selection; these would be given below in the VOTable output fields.

NameTable Head DescriptionUnitUCD
_r Dist. Distance to cone center deg pos.distance
adoptedrv ad. RV Adopted Radial Velocity km/s phys.veloc;pos.heliocentric
dec Dec ICRS declination from Gaia eDR3. deg pos.eq.dec;meta.main
dec_error Err. Dec Standard error of dec mas stat.error;pos.eq.dec
dist_1 Dist1 1st percentile of the distance PDF, used in GCNS selection kpc stat.value;pos.distance
dist_16 Dist16 16th percentile of the distance PDF (1 σ lower bound) kpc stat.value;pos.distance
dist_50 Dist50 Median of the distance PDF kpc stat.median;pos.distance
dist_84 Dist84 84th percentile of the distance PDF (1 σ upper bound) kpc stat.value;pos.distance
gcns_prob Astrom? Probability that the astrometry is reliable N/A stat.fit.goodness
gmag_gunn m_g Gunn G band magnitude (when from SDSS, g, when from Skymapper, g_psf) mag phot.mat;em.opt.V
h_m_2mass m_H 2MASS H band magnitude mag phot.mag;em.IR.H
imag_gunn m_i Gunn I band magnitude (when from SDSS, g, when from Skymapper, g_psf) mag phot.mat;em.opt.I
ipd_frac_multi_peak Double? Percentage of distance windows in which a double peak was seen (high values mean high likelihood of a resolved double star). N/A meta.code.multip
j_m_2mass m_J 2MASS J band magnitude mag phot.mag;em.IR.J
k_m_2mass m_K 2MASS K band magnitude mag phot.mag;em.IR.K
name_2mass 2MASS name Name of this object in 2MASS N/A meta.id.cross
name_gunn Gunn Name Object Name from PanSTARRS/SDSS/SkyMapper survey N/A meta.id.cross
name_wise WISE name Name of this object in WISE N/A meta.id.cross
parallax Parallax Absolute barycentric stellar parallax of the source at the reference epoch J2016.0. If looking for a distance, consider joining with gedr3dist.main and using the distances from there. mas pos.parallax
parallax_error Parallax_error Standard error of parallax mas stat.error;pos.parallax
phot_bp_mean_flux_over_error SNR BP Integrated mean BP flux divided by its error. Errors are computed from the dispersion about the weighted mean of the input calibrated photometry. Note e N/A stat.snr;phot.flux;em.opt.B
phot_bp_mean_mag Mag BP Mean magnitude in the integrated BP band. This is computed from the BP-band mean flux applying the magnitude zero-point in the Vega scale. To obtain error estimates, see phot_bp_mean_flux_over_error. mag phot.mag;em.opt.B
phot_bp_rp_excess_factor BP/RP excess BP/RP excess factor estimated from the comparison of the sum of integrated BP and RP fluxes with respect to the flux in the G band. This measures the excess of flux in the BP and RP integrated photometry with respect to the G band. This excess is believed to be caused by background and contamination issues affecting the BP and RP data. Therefore a large value of this factor for a given source indicates systematic errors in the BP and RP photometry. N/A stat.fit.goodness
phot_g_mean_flux_over_error SNR G Integrated mean G flux divided by its error. Errors are computed from the dispersion about the weighted mean of the input calibrated photometry. Note e s**-1 stat.snr;phot.flux;em.opt;stat.mean
phot_g_mean_mag m_G Mean magnitude in the G band. This is computed from the G-band mean flux applying the magnitude zero-point in the Vega scale. To obtain error estimates, see phot_g_mean_flux_over_error. mag phot.mag;em.opt;stat.mean
phot_rp_mean_flux_over_error SNR RP Integrated mean RP flux divided by its error. Errors are computed from the dispersion about the weighted mean of the input calibrated photometry. Note e N/A stat.snr;phot.flux;em.opt.R
phot_rp_mean_mag Mag RP Mean magnitude in the integrated RP band. This is computed from the RP-band mean flux applying the magnitude zero-point in the Vega scale. To obtain error estimates, see phot_rp_mean_flux_over_error. mag phot.mag;em.opt.R
pmdec µ(Dec) Proper motion in declination at J2016.0. mas/yr pos.pm;pos.eq.dec
pmdec_error Err. PM(Dec) Standard error of pmdec mas/yr stat.error;pos.pm;pos.eq.dec
pmra µ(RA) Proper motion in right ascension of the source in ICRS at J2016.0. This is the tangent plane projection of the proper motion vector in the direction of increasing right ascension. mas/yr pos.pm;pos.eq.ra
pmra_error Err. PM(RA) Standard error of pmra mas/yr stat.error;pos.pm;pos.eq.ra
ra RA ICRS right ascension from Gaia eDR3. deg pos.eq.ra;meta.main
ra_error Err. RA Standard error of ra (with cos δ applied). mas stat.error;pos.eq.ra
rmag_gunn m_r Gunn R band magnitude (when from SDSS, g, when from Skymapper, g_psf) mag phot.mat;em.opt.R
ruwe RUWE Renormalized Unit Weight Error; this is a revised measure for the overall consistency of the solution as defined by GAIA-C3-TN-LU-LL-124-01. A suggested cut on this is RUWE <1.40) See the note for details. Note ruwe N/A stat.weight
source_id Source Id Gaia eDR3 unique source identifier. Note that this *cannot* be matched against the DR1 or DR2 source_ids. Note id N/A meta.id;meta.main
uvel_16 Lo U 1 σ lower bound for u km/s stat.value;phys.veloc;pos.cartesian.x
uvel_50 U Median velocity u in the Galactic frame, direction positive x km/s stat.median;phys.veloc;pos.cartesian.x
uvel_84 Hi U 1 σ upper bound for u km/s stat.value;phys.veloc;pos.cartesian.x
vvel_16 Lo V 1 σ lower bound for v km/s stat.value;phys.veloc;pos.cartesian.y
vvel_50 V Median velocity v in the Galactic frame, direction positive y km/s stat.median;phys.veloc;pos.cartesian.y
vvel_84 Hi V 1 σ upper bound for v km/s stat.value;phys.veloc;pos.cartesian.y
w1mpro_pm_wise m_W1 CATWISE W1 band magnitude mag phot.mag;em.IR.3-4um
w2mpro_pm_wise m_W2 CATWISE W2 band magnitude mag phot.mag;em.IR.4-8um
w3mpro_wise m_W3 CATWISE W3 band magnitude mag phot.mag;em.IR.8-15um
w4mpro_wise m_W4 ALLWISE W4 band magnitude mag phot.mag;em.IR.15-30um
wd_prob WD? probability that this is a white dwarf. N/A stat.likelihood;src.class
wvel_16 Lo W 1 σ lower bound for w km/s stat.value;phys.veloc;pos.cartesian.z
wvel_50 W Median velocity w in the Galactic frame, direction positive z km/s stat.median;phys.veloc;pos.cartesian.z
wvel_84 Hi W 1 σ upper bound for w km/s stat.value;phys.veloc;pos.cartesian.z
xcoord_16 Lo X 1 σ lower bound of Galactic frame x coordinate pc stat.value;pos.cartesian.x
xcoord_50 X Median x coordinate in the Galactic frame assuming dist_50 pc stat.median;pos.cartesian.x
xcoord_84 Hi X 1 σ upper bound of Galactic frame x coordinate pc stat.value;pos.cartesian.x
ycoord_16 Lo Y 1 σ lower bound of Galactic frame y coordinate pc stat.value;pos.cartesian.y
ycoord_50 Y Median y coordinate in the Galactic frame assuming dist_50 pc stat.median;pos.cartesian.y
ycoord_84 Hi Y 1 σ upper bound of Galactic frame y coordinate pc stat.value;pos.cartesian.y
zcoord_16 Lo Z 1 σ lower bound of Galactic frame z coordinate pc stat.value;pos.cartesian.z
zcoord_50 Z Median z coordinate in the Galactic frame assuming dist_50 pc stat.median;pos.cartesian.z
zcoord_84 Hi Z 1 σ upper bound of Galactic frame z coordinate pc stat.value;pos.cartesian.z
zmag_gunn m_z Gunn Z band magnitude (when from SDSS, g, when from Skymapper, g_psf) mag phot.mat;em.opt.I

VOTable Output Fields

The following fields are available in VOTable output. The verbosity level is a number intended to represent the relative importance of the field on a scale of 1 to 30. The services take a VERB argument. A field is included in the output if their verbosity level is less or equal VERB*10.

NameTable Head DescriptionUnitUCD Verb. Level
source_id Source Id Gaia eDR3 unique source identifier. Note that this *cannot* be matched against the DR1 or DR2 source_ids. Note id N/A meta.id;meta.main 1
ra RA ICRS right ascension from Gaia eDR3. deg pos.eq.ra;meta.main 1
dec Dec ICRS declination from Gaia eDR3. deg pos.eq.dec;meta.main 1
parallax Parallax Absolute barycentric stellar parallax of the source at the reference epoch J2016.0. If looking for a distance, consider joining with gedr3dist.main and using the distances from there. mas pos.parallax 1
pmra µ(RA) Proper motion in right ascension of the source in ICRS at J2016.0. This is the tangent plane projection of the proper motion vector in the direction of increasing right ascension. mas/yr pos.pm;pos.eq.ra 1
pmdec µ(Dec) Proper motion in declination at J2016.0. mas/yr pos.pm;pos.eq.dec 1
phot_g_mean_mag m_G Mean magnitude in the G band. This is computed from the G-band mean flux applying the magnitude zero-point in the Vega scale. To obtain error estimates, see phot_g_mean_flux_over_error. mag phot.mag;em.opt;stat.mean 1
phot_bp_mean_mag Mag BP Mean magnitude in the integrated BP band. This is computed from the BP-band mean flux applying the magnitude zero-point in the Vega scale. To obtain error estimates, see phot_bp_mean_flux_over_error. mag phot.mag;em.opt.B 1
phot_rp_mean_mag Mag RP Mean magnitude in the integrated RP band. This is computed from the RP-band mean flux applying the magnitude zero-point in the Vega scale. To obtain error estimates, see phot_rp_mean_flux_over_error. mag phot.mag;em.opt.R 1
ruwe RUWE Renormalized Unit Weight Error; this is a revised measure for the overall consistency of the solution as defined by GAIA-C3-TN-LU-LL-124-01. A suggested cut on this is RUWE <1.40) See the note for details. Note ruwe N/A stat.weight 5
ipd_frac_multi_peak Double? Percentage of distance windows in which a double peak was seen (high values mean high likelihood of a resolved double star). N/A meta.code.multip 5
xcoord_50 X Median x coordinate in the Galactic frame assuming dist_50 pc stat.median;pos.cartesian.x 5
ycoord_50 Y Median y coordinate in the Galactic frame assuming dist_50 pc stat.median;pos.cartesian.y 5
zcoord_50 Z Median z coordinate in the Galactic frame assuming dist_50 pc stat.median;pos.cartesian.z 5
uvel_50 U Median velocity u in the Galactic frame, direction positive x km/s stat.median;phys.veloc;pos.cartesian.x 5
vvel_50 V Median velocity v in the Galactic frame, direction positive y km/s stat.median;phys.veloc;pos.cartesian.y 5
wvel_50 W Median velocity w in the Galactic frame, direction positive z km/s stat.median;phys.veloc;pos.cartesian.z 5
_r Dist. Distance to cone center deg pos.distance 10
dist_50 Dist50 Median of the distance PDF kpc stat.median;pos.distance 10
adoptedrv ad. RV Adopted Radial Velocity km/s phys.veloc;pos.heliocentric 15
gcns_prob Astrom? Probability that the astrometry is reliable N/A stat.fit.goodness 15
wd_prob WD? probability that this is a white dwarf. N/A stat.likelihood;src.class 15
dist_16 Dist16 16th percentile of the distance PDF (1 σ lower bound) kpc stat.value;pos.distance 15
xcoord_16 Lo X 1 σ lower bound of Galactic frame x coordinate pc stat.value;pos.cartesian.x 15
ycoord_16 Lo Y 1 σ lower bound of Galactic frame y coordinate pc stat.value;pos.cartesian.y 15
zcoord_16 Lo Z 1 σ lower bound of Galactic frame z coordinate pc stat.value;pos.cartesian.z 15
uvel_16 Lo U 1 σ lower bound for u km/s stat.value;phys.veloc;pos.cartesian.x 15
uvel_84 Hi U 1 σ upper bound for u km/s stat.value;phys.veloc;pos.cartesian.x 15
vvel_16 Lo V 1 σ lower bound for v km/s stat.value;phys.veloc;pos.cartesian.y 15
vvel_84 Hi V 1 σ upper bound for v km/s stat.value;phys.veloc;pos.cartesian.y 15
wvel_16 Lo W 1 σ lower bound for w km/s stat.value;phys.veloc;pos.cartesian.z 15
wvel_84 Hi W 1 σ upper bound for w km/s stat.value;phys.veloc;pos.cartesian.z 15
name_gunn Gunn Name Object Name from PanSTARRS/SDSS/SkyMapper survey N/A meta.id.cross 15
gmag_gunn m_g Gunn G band magnitude (when from SDSS, g, when from Skymapper, g_psf) mag phot.mat;em.opt.V 15
rmag_gunn m_r Gunn R band magnitude (when from SDSS, g, when from Skymapper, g_psf) mag phot.mat;em.opt.R 15
imag_gunn m_i Gunn I band magnitude (when from SDSS, g, when from Skymapper, g_psf) mag phot.mat;em.opt.I 15
zmag_gunn m_z Gunn Z band magnitude (when from SDSS, g, when from Skymapper, g_psf) mag phot.mat;em.opt.I 15
name_2mass 2MASS name Name of this object in 2MASS N/A meta.id.cross 15
j_m_2mass m_J 2MASS J band magnitude mag phot.mag;em.IR.J 15
h_m_2mass m_H 2MASS H band magnitude mag phot.mag;em.IR.H 15
k_m_2mass m_K 2MASS K band magnitude mag phot.mag;em.IR.K 15
name_wise WISE name Name of this object in WISE N/A meta.id.cross 15
w1mpro_pm_wise m_W1 CATWISE W1 band magnitude mag phot.mag;em.IR.3-4um 15
w2mpro_pm_wise m_W2 CATWISE W2 band magnitude mag phot.mag;em.IR.4-8um 15
w3mpro_wise m_W3 CATWISE W3 band magnitude mag phot.mag;em.IR.8-15um 15
w4mpro_wise m_W4 ALLWISE W4 band magnitude mag phot.mag;em.IR.15-30um 15
ra_error Err. RA Standard error of ra (with cos δ applied). mas stat.error;pos.eq.ra 20
dec_error Err. Dec Standard error of dec mas stat.error;pos.eq.dec 20
parallax_error Parallax_error Standard error of parallax mas stat.error;pos.parallax 20
pmra_error Err. PM(RA) Standard error of pmra mas/yr stat.error;pos.pm;pos.eq.ra 20
pmdec_error Err. PM(Dec) Standard error of pmdec mas/yr stat.error;pos.pm;pos.eq.dec 20
phot_g_mean_flux_over_error SNR G Integrated mean G flux divided by its error. Errors are computed from the dispersion about the weighted mean of the input calibrated photometry. Note e s**-1 stat.snr;phot.flux;em.opt;stat.mean 20
phot_bp_mean_flux_over_error SNR BP Integrated mean BP flux divided by its error. Errors are computed from the dispersion about the weighted mean of the input calibrated photometry. Note e N/A stat.snr;phot.flux;em.opt.B 20
phot_rp_mean_flux_over_error SNR RP Integrated mean RP flux divided by its error. Errors are computed from the dispersion about the weighted mean of the input calibrated photometry. Note e N/A stat.snr;phot.flux;em.opt.R 20
phot_bp_rp_excess_factor BP/RP excess BP/RP excess factor estimated from the comparison of the sum of integrated BP and RP fluxes with respect to the flux in the G band. This measures the excess of flux in the BP and RP integrated photometry with respect to the G band. This excess is believed to be caused by background and contamination issues affecting the BP and RP data. Therefore a large value of this factor for a given source indicates systematic errors in the BP and RP photometry. N/A stat.fit.goodness 20
dist_1 Dist1 1st percentile of the distance PDF, used in GCNS selection kpc stat.value;pos.distance 20
dist_84 Dist84 84th percentile of the distance PDF (1 σ upper bound) kpc stat.value;pos.distance 20
xcoord_84 Hi X 1 σ upper bound of Galactic frame x coordinate pc stat.value;pos.cartesian.x 20
ycoord_84 Hi Y 1 σ upper bound of Galactic frame y coordinate pc stat.value;pos.cartesian.y 20
zcoord_84 Hi Z 1 σ upper bound of Galactic frame z coordinate pc stat.value;pos.cartesian.z 20
adoptedrv_error Err. RV Error in adopted RV km/s stat.error;phys.veloc;pos.heliocentric 25
adoptedrv_refname Src RV Bibcode for the source of the radial velocity N/A meta.bib.bibcode 25
radial_velocity_is_valid RV? 1 if this object has a radial velocity in eDR3, 0 otherwise N/A meta.code.qual 25
refname_gunn Ref. griz Reference for the source of the Gunn photometry N/A meta.bib.bibcode 25
e_gmag_gunn Err. m_g Uncertainty in G band magnitude mag stat.error;phot.mat;em.opt.V 25
e_rmag_gunn Err. m_r Uncertainty in R band magnitude mag stat.error;phot.mat;em.opt.R 25
e_imag_gunn Err. m_i Uncertainty in I band magnitude mag stat.error;phot.mat;em.opt.I 25
e_zmag_gunn Err. m_z Uncertainty in Z band magnitude mag stat.error;phot.mat;em.opt.I 25
j_msig_2mass Err. m_J Uncertainty in 2MASS J band magnitude mag stat.error;phot.mag;em.IR.J 25
h_msig_2mass Err. m_H Uncertainty in 2MASS H band magnitude mag stat.error;phot.mag;em.IR.H 25
k_msig_2mass Err. m_K Uncertainty in 2MASS K band magnitude mag stat.error;phot.mag;em.IR.K 25
w1sigmpro_pm_wise Err. m_W1 Uncertainty in CATWISE W1 band magnitude mag stat.error;phot.mag;em.IR.3-4um 25
w2sigmpro_pm_wise Err. m_W2 Uncertainty in CATWISE W2 band magnitude mag stat.error;phot.mag;em.IR.4-8um 25
w3sigmpro_wise Err. m_W3 Uncertainty in CATWISE W3 band magnitude mag stat.error;phot.mag;em.IR.8-15um 25
w4sigmpro_wise Err. m_W4 Uncertainty in ALLWISE W4 band magnitude mag stat.error;phot.mag;em.IR.15-30um 25

VOResource XML (that's something exclusively for VO nerds)

Note e

As long as the SNR is larger than 10 or so, 1.09*mag/snr is a reasonable approximation for an roughly symmetric magnitude error. For smaller SNR, the error distribution of the magnitude becomes very asymmetric and highly non-Gaussian.

Note id

For the contents of Gaia eDR3, the source ID consists of a 64-bit integer, least significant bit = 1 and most significant bit = 64, comprising:

  • a HEALPix index number (sky pixel) in bits 36 - 63; by definition the
    smallest HEALPix index number is zero.
  • a 2-bit Data Processing Centre code in bits 34 - 35; for example
    MOD(source_id / 4294967296, 8) can be used to distinguish between sources initialised via the Initial Gaia Source List by the Torino DPC (code = 0) and sources otherwise detected and assigned by Gaia observations (code > 0)
  • a 25-bit plus 7 bit sequence number within the HEALPix pixel in bits 1
    to 32 split into:
    • a 25 bit running number in bits 8 x 32; the running numbers are
      defined to be positive, i.e. never zero (except in the case of forced empty windows)
    • a 7-bit component number in bits 1 x 7 one spare bit in bit 33

This means that the HEALpix index level 12 of a given source is contained in the most significant bits. HEALpix index of 12 and lower levels can thus be retrieved as follows:

  • HEALpix level 12 = source_id / 34359738368
  • HEALpix level 11 = source_id / 137438953472
  • HEALpix level 10 = source_id / 549755813888
  • HEALpix level n = source_id / 2^35 * 4^(12 - level).
Note ruwe

The Renormalized Unit Weight Error (RUWE) is defined in L. Lindegren: Re-normalising the astrometric chi-square in Gaia DR2 (Gaia tech note GAIA-C3-TN-LU-LL-124-01). This is essentially the astrometric_chi2 from the DR2 release, but corrected for its strong dependency on magnitude and colour. For quality cuts, this is the recommended quantity to use. Lindegren suggests using RUWE<1.4 as a quality cut for “good” solutions based on the shape of the distribution.

The values given here were calculated independently of DPAC and do not use interpolation on the grids provided by Lindegren et al. Thus, minor differences from the “official” RUWE values are expected. As Lindegren et al point out, such differences should not matter in science applications, though.