Table and column metadata

Table Meta-document for AstroGrid DSA/CATS for Astro-catalogs dataset

Table twomass_psc

The 2MASS Point Source catalogue of 470,992,970 sources.

ColumnTypeUnitsUCDErrorDescriptionLinks
radoubledegpos.eq.ra;meta.main(ra) Right ascension (J2000)
decldoubledegpos.eq.dec;meta.main(dec) Declination (J2000)
err_majdoublearcsecstat.error(err_maj) Major axis of position error ellipse
err_mindoublearcsecstat.error(err_min) Minor axis of position error ellipse
err_angintdegstat.error[0,180] (err_ang) Position angle of error ellipse major axis (E of N)
designationstringcharmeta.id;meta.main(designation) Source designation
j_mdoublemagphot.mag;em.IR.J(j_m) J selected default magnitude
j_cmsigdoublemagstat.error;phot.mag(j_cmsig) J default magnitude uncertainty
j_msigcomdoublemagstat.error;phot.mag;em.IR.J(j_msigcom) J total magnitude uncertainty
j_snrdoublemagstat.snr(j_snr) J Signal-to-noise ratio
h_mdoublemagphot.mag;em.IR.H(h_m) H selected default magnitude
h_cmsigdoublemagstat.error;phot.mag(h_cmsig) H default magnitude uncertainty
h_msigcomdoublemagstat.error;phot.mag;em.IR.H(h_msigcom) H total magnitude uncertainty
h_snrdoublemagstat.snr(h_snr) H Signal-to-noise ratio
k_mdoublemagphot.mag;em.IR.K(k_m) K selected default magnitude
k_cmsigdoublemagstat.error;phot.mag(k_cmsig) K default magnitude uncertainty
k_msigcomdoublemagstat.error;phot.mag;em.IR.K(k_msigcom) K total magnitude uncertainty
k_snrdoublemagstat.snr(k_snr) K Signal-to-noise ratio
ph_qualstringmeta.code.qual;phot(ph_qual) JHK Photometric quality flag
rd_flgstringmeta.ref(rd_flg) Source of JHK default mag
bl_flgstringmeta.code(bl_flg) JHK components fit to source
cc_flgstringmeta.code(cc_flg) Artifact contamination, confusion
ndetstringmeta.number[0-9] (ndet) Number of aperture measurements (jjhhkk)
proxdoublearcsecpos.angDistanceDistance between source and nearest neighbour
pxpaintdegpos.posAng(pxpa) Position angle of vector from source to nearest neighbour (E of N)
pxcntrintmeta.number(pxcntr) Sequence number of nearest neighbour
gal_contamintmeta.code[0,2] (gal_contam) Extended source contamination
mp_flgintmeta.code[0,1] (mp_flg) Association with asteroid or comet
pts_keyintmeta.id;meta.table(pts_key) Unique source identifier in catalogue
hemischarobs.param;obs[ns] (hemis) Hemisphere of observation
datedateTimetime.epoch;obs(date) Observation date
scanintobs.field(scan) Scan number (within date)
glondoubledegos.galactic.lon(glon) Galactic longitude
glatdoubledegpos.galactic.lat(glat) Galactic latitude
x_scandoublearcsecpos.cartesian;instr.det(x_scan) Distance of source from focal plane centerline
jdatedoubleJulian daystime.epoch(jdate) Julian date of source measurement
j_psfchidoublemagstat.fit.chi2;stat.value(j_psfchi) J band reduced chi2 value of fit
h_psfchidoublemagstat.fit.chi2;stat.value(h_psfchi) H band reduced chi2 value of fit
k_psfchidoublemagstat.fit.chi2;stat.value(k_psfchi) K band reduced chi2 value of fit
j_m_stdapdoublemagphot.mag;em.IR.J(jmstdap) J standard aperture magnitude
j_msig_stdapdoublemagstat.error(jmsigstdap) error on Jstdap
h_m_stdapdoublemagphot.mag;em.IR.H(hmstdap) H standard aperture magnitude
h_msig_stdapdoublemagstat.error(hmsigstdap) error on Hstdap
k_m_stdapdoublemagphot.mag;em.IR.K(kmstdap) K standard aperture magnitude
k_msig_stdapdoublemagstat.error(kmsigstdap) error on Kstdap
dist_edge_nsintarcsecpos;arith.diff(distedgens) Distance from the source to the nearest North or South scan edge
dist_edge_ewintarcsecpos;arith.diff(distedgeew) Distance from the source to the nearest East or West scan edge
dist_edge_flgstringpos.cartesian;instr.det(distedgeflg) flag indicating to which edges the edgeNS and edgeEW values refer
dup_srcintmeta.code(dup_src) Flag indicating duplicate source
use_srcintmeta.code(use_src) Use source flag
acharmeta.id;meta.dataset(a) Associated optical source
dist_optdoublearcsecpos.angDistance(dist_opt) Distance to associated optical source
phi_optintdegpos.posAng[0,360] (phi_opt) position angle from optical source to the 2MASS source position
b_m_optdoublemagphot.mag;em.opt.B(bmopt) Blue magnitude of associated optical source
vr_m_optdoublemagphot.mag;em.opt.R(vrmopt) Visual or red mag of associated optical source
nopt_mchsintmeta.number(nopt_mchs) Number of optical sources within 5arcsec
ext_keyintmeta.id.cross(ext_key) Record Identifier in XSC
scan_keyintmeta.id(scan_key) Record Identifier in the Scan Information Table
coadd_keyintmeta.id;meta.dataset(coadd_key) Record Identifier in the Atlas Image Data Table
coaddintmeta.number(coadd) Sequence number of the Atlas Image

Table twomass_xsc

The XSC contains 389 columns of information per source (most of which is photometry.) Because extended sources are much more complicated than a point source, it takes many more parameters to characterize them. Some parameters are required to describe the spatial extent of a source, and many more are required to characterize the photometry. In addition to a number of standard measures of photometry, the xsc also reports the magnitude as measured in a number of different fixed-size apertures. The table is organized according to the broad function and utility of the parameters: Name and Position Information, Standard Photometry and Orientation, Large Aperture Photometry, and Miscellaneous Photometry and Characterization.

ColumnTypeUnitsUCDErrorDescriptionLinks
jdatedoubleJulian days Julian date of the source measurement accurate to +-3 minutes.
designationstring Source designation formed from sexigesimal coordinates.
radoubledeg Right ascension (J2000 decimal deg) based on peak pixel.
decldoubledeg Declination (J2000 decimal deg) based on peak pixel.
sup_radoubledeg Super-coadd centroid RA (J2000 decimal deg).
sup_decdoubledeg Super-coadd centroid Dec (J2000 decimal deg).
glondoubledeg Galactic longitude (decimal deg) based on peak pixel.
glatdoubledeg Galactic latitude (decimal deg) based on peak pixel.
densitydouble Coadd log(density) of stars with k lover 14 mag.
r_k20fedoublearcsec 20mag/sq." isophotal K fiducial ell. ap. semi-major axis.
j_m_k20fedoublemag J 20mag/sq." isophotal fiducial ell. ap. magnitude.
j_msig_k20fedoublemag J 1-sigma uncertainty in 20mag/sq." iso.fid.ell.mag.
j_flg_k20feint J confusion flag for 20mag/sq." iso. fid. ell. mag.
h_m_k20fedoublemag H 20mag/sq." isophotal fiducial ell. ap. magnitude.
h_msig_k20fedoublemag H 1-sigma uncertainty in 20mag/sq." iso.fid.ell.mag.
h_flg_k20feint H confusion flag for 20mag/sq." iso. fid. ell. mag.
k_m_k20fedoublemag K 20mag/sq." isophotal fiducial ell. ap. magnitude.
k_msig_k20fedoublemag K 1-sigma uncertainty in 20mag/sq." iso.fid.ell.mag
k_flg_k20feint K 1-sigma uncertainty in 20mag/sq." iso.fid.ell.mag
r_3sigdoublearcsec 3-sigma K isophotal semi-major axis.
j_badouble J minor/major axis ratio fit to the 3-sigma isophote.
j_phiint J angle to 3-sigma major axis (E of N).
h_badouble H minor/major axis ratio fit to the 3-sigma isophote.
h_phiint H angle to 3-sigma major axis (E of N).
k_badouble K minor/major axis ratio fit to the 3-sigma isophote.
k_phiint K angle to 3-sigma major axis (E of N).
sup_r_3sigdoublearcsec Super-coadd 3-sigma isophotal semi-major axis radius.
sup_badouble Minor/major axis ratio fit to 3-sig. super-coadd isophote.
sup_phiintdeg Super-coadd angle to major axis (E of N).
r_fedoublearcsec K fiducial Kron elliptical aperture semi-major axis.
j_m_fedoublemag J fiducial Kron ell. mag aperture magnitude.
j_msig_fedoublemag J 1-sigma uncertainty in fiducial Kron ell. mag.
j_flg_feint J confusion flag for fiducial Kron ell. mag.
h_m_fedoublemag H fiducial Kron ell. mag aperture magnitude.
h_msig_fedoublemag H 1-sigma uncertainty in fiducial Kron ell. mag.
h_flg_feint H confusion flag for fiducial Kron ell. mag.
k_m_fedoublemag K fiducial Kron ell. mag aperture magnitude.
k_msig_fedoublemag K 1-sigma uncertainty in fiducial Kron ell. mag.
k_flg_feint K confusion flag for fiducial Kron ell. mag.
r_extdoublearcsec extrapolation/total radius.
j_m_extdoublemag J mag from fit extrapolation.
j_msig_extdoublemag J 1-sigma uncertainty in mag from fit extrapolation.
j_pchidouble J chi^2 of fit to rad. profile (LCSB: alpha scale len).
h_m_extdoublemag H mag from fit extrapolation.
h_msig_extdoublemag H 1-sigma uncertainty in mag from fit extrapolation.
h_pchidouble H chi^2 of fit to rad. profile (LCSB: alpha scale len).
k_m_extdoublemag K mag from fit extrapolation.
k_msig_extdoublemag K 1-sigma uncertainty in mag from fit extrapolation.
k_pchidouble K chi^2 of fit to rad. profile (LCSB: alpha scale len).
j_r_effdoublearcsec J half-light (integrated half-flux point) radius.
j_mnsurfb_effdoublemag J mean surface brightness at the half-light radius.
h_r_effdoublearcsec H half-light (integrated half-flux point) radius.
h_mnsurfb_effdoublemag H mean surface brightness at the half-light radius.
k_r_effdoublearcsec K half-light (integrated half-flux point) radius.
k_mnsurfb_effdoublemag K mean surface brightness at the half-light radius.
j_con_indxdouble J concentration index r_75%/r_25%.
h_con_indxdouble H concentration index r_75%/r_25%.
k_con_indxdouble K concentration index r_75%/r_25%.
j_peakdoublemag J peak pixel brightness.
h_peakdoublemag H peak pixel brightness
k_peakdoublemag K peak pixel brightness.
j_5surfdoublemag J central surface brightness (r lover or =5).
h_5surfdoublemag H central surface brightness (r lover or =5).
k_5surfdoublemag K central surface brightness (r lover or =5).
e_scoredouble extended score: 1(extended) lover e_score and lover 2(point-like).
g_scoredouble galaxy score: 1(extended) lover g_score and lover 2(point-like).
vcint visual verification score for source.
cc_flgchar indicates artifact contamination and/or confusion.
im_nxint size of postage stamp image in pixels.
r_k20fcdoublearcsec 20mag/sq." isophotal K fiducial circular ap. radius.
j_m_k20fcdoublemag J 20mag/sq." isophotal fiducial circ. ap. mag.
j_msig_k20fcdoublemag J 1-sigma uncertainty in 20mag/sq." iso.fid.circ. mag.
j_flg_k20fcint J confusion flag for 20mag/sq." iso. fid. circ. mag.
h_m_k20fcdoublemag H 20mag/sq." isophotal fiducial circ. ap. mag.
h_msig_k20fcdoublemag H 1-sigma uncertainty in 20mag/sq." iso.fid.circ. mag.
h_flg_k20fcint H confusion flag for 20mag/sq." iso. fid. circ. mag.
k_m_k20fcdoublemag K 20mag/sq." isophotal fiducial circ. ap. mag.
k_msig_k20fcdoublemag K 1-sigma uncertainty in 20mag/sq." iso.fid.circ. mag.
k_flg_k20fcint K confusion flag for 20mag/sq." iso. fid. circ. mag.
j_r_edoublearcsec J Kron elliptical aperture semi-major axis.
j_m_edoublemag J Kron elliptical aperture magnitude.
j_msig_edoublemag J 1-sigma uncertainty in Kron elliptical mag.
j_flg_eint J confusion flag for Kron elliptical mag.
h_r_edoublearcsec H Kron elliptical aperture semi-major axis.
h_m_edoublemag H Kron elliptical aperture magnitude.
h_msig_edoublemag H 1-sigma uncertainty in Kron elliptical mag.
h_flg_eint H confusion flag for Kron elliptical mag.
k_r_edoublearcsec K Kron elliptical aperture semi-major axis.
k_m_edoublemag K Kron elliptical aperture magnitude.
k_msig_edoublemag K 1-sigma uncertainty in Kron elliptical mag.
k_flg_eint K confusion flag for Kron elliptical mag.
j_r_cdoublearcsec J Kron circular aperture radius.
j_m_cdoublemag J Kron circular aperture magnitude.
j_msig_cdoublemag J 1-sigma uncertainty in Kron circular mag.
j_flg_cint J confusion flag for Kron circular mag.
h_r_cdoublearcsec H Kron circular aperture radius.
h_m_cdoublemag H Kron circular aperture magnitude.
h_msig_cdoublemag H 1-sigma uncertainty in Kron circular mag.
h_flg_cint H confusion flag for Kron circular mag.
k_r_cdoublearcsec K Kron circular aperture radius.
k_m_cdoublemag K Kron circular aperture magnitude.
k_msig_cdoublemag K 1-sigma uncertainty in Kron circular mag.
k_flg_cint K confusion flag for Kron circular mag.
r_fcdoublearcsec K fiducial Kron circular aperture radius.
j_m_fcdoublemag J fiducial Kron circular magnitude.
j_msig_fcdoublemag J 1-sigma uncertainty in fiducial Kron circ. mag.
j_flg_fcint J confusion flag for fiducial Kron circ. mag.
h_m_fcdoublemag H fiducial Kron circular magnitude.
h_msig_fcdoublemag H 1-sigma uncertainty in fiducial Kron circ. mag.
h_flg_fcint H confusion flag for fiducial Kron circ. mag.
k_m_fcdoublemag K fiducial Kron circular magnitude.
k_msig_fcdoublemag K 1-sigma uncertainty in fiducial Kron circ. mag.
k_flg_fcint K confusion flag for fiducial Kron circ. mag.
j_r_i20edoublearcsec J 20mag/sq." isophotal elliptical ap. semi-major axis.
j_m_i20edoublemag J 20mag/sq." isophotal elliptical ap. magnitude.
j_msig_i20edoublemag J 1-sigma uncertainty in 20mag/sq." iso. ell. mag.
j_flg_i20eint J confusion flag for 20mag/sq." iso. ell. mag.
h_r_i20edoublearcsec H 20mag/sq." isophotal elliptical ap. semi-major axis.
h_m_i20edoublemag H 20mag/sq." isophotal elliptical ap. magnitude.
h_msig_i20edoublemag H 1-sigma uncertainty in 20mag/sq." iso. ell. mag.
h_flg_i20eint H confusion flag for 20mag/sq." iso. ell. mag.
k_r_i20edoublearcsec K 20mag/sq." isophotal elliptical ap. semi-major axis.
k_m_i20edoublemag K 20mag/sq." isophotal elliptical ap. magnitude.
k_msig_i20edoublemag K 1-sigma uncertainty in 20mag/sq." iso. ell. mag.
k_flg_i20eint K confusion flag for 20mag/sq." iso. ell. mag.
j_r_i20cdoublearcsec J 20mag/sq." isophotal circular aperture radius.
j_m_i20cdoublemag J 20mag/sq." isophotal circular ap. magnitude.
j_msig_i20cdoublemag J 1-sigma uncertainty in 20mag/sq." iso. circ. mag.
j_flg_i20cint J confusion flag for 20mag/sq." iso. circ. mag.
h_r_i20cdoublearcsec H 20mag/sq." isophotal circular aperture radius.
h_m_i20cdoublemag H 20mag/sq." isophotal circular ap. magnitude.
h_msig_i20cdoublemag H 1-sigma uncertainty in 20mag/sq." iso. circ. mag.
h_flg_i20cint H confusion flag for 20mag/sq." iso. circ. mag.
k_r_i20cdoublearcsec K 20mag/sq." isophotal circular aperture radius.
k_m_i20cdoublemag K 20mag/sq." isophotal circular ap. magnitude.
k_msig_i20cdoublemag K 1-sigma uncertainty in 20mag/sq." iso. circ. mag.
k_flg_i20cint K confusion flag for 20mag/sq." iso. circ. mag.
j_r_i21edoublearcsec J 21mag/sq." isophotal elliptical ap. semi-major axis.
j_m_i21edoublemag J 21mag/sq." isophotal elliptical ap. magnitude.
j_msig_i21edoublemag J 1-sigma uncertainty in 21mag/sq." iso. ell. mag.
j_flg_i21eint J confusion flag for 21mag/sq." iso. ell. mag.
h_r_i21edoublearcsec H 21mag/sq." isophotal elliptical ap. semi-major axis.
h_m_i21edoublemag H 21mag/sq." isophotal elliptical ap. magnitude.
h_msig_i21edoublemag H 1-sigma uncertainty in 21mag/sq." iso. ell. mag.
h_flg_i21eint H confusion flag for 21mag/sq." iso. ell. mag.
k_r_i21edoublearcsec K 21mag/sq." isophotal elliptical ap. semi-major axis.
k_m_i21edoublemag K 21mag/sq." isophotal elliptical ap. magnitude.
k_msig_i21edoublemag K 1-sigma uncertainty in 21mag/sq." iso. ell. mag.
k_flg_i21eint K confusion flag for 21mag/sq." iso. ell. mag.
r_j21fedoublearcsec 21mag/sq." isophotal J fiducial ell. ap. semi-major axis.
j_m_j21fedoublemag J 21mag/sq." isophotal fiducial ell. ap. magnitude.
j_msig_j21fedoublemag J 21mag/sq." isophotal fiducial ell. ap. magnitude.
j_flg_j21feint J confusion flag for 21mag/sq." iso. fid. ell. mag.
h_m_j21fedoublemag H 21mag/sq." isophotal fiducial ell. ap. magnitude.
h_msig_j21fedoublemag H 1-sigma uncertainty in 21mag/sq." iso.fid.ell.mag.
h_flg_j21feint H confusion flag for 21mag/sq." iso. fid. ell. mag.
k_m_j21fedoublemag K 21mag/sq." isophotal fiducial ell. ap. magnitude.
k_msig_j21fedoublemag K 1-sigma uncertainty in 21mag/sq." iso.fid.ell.mag.
k_flg_j21feint K confusion flag for 21mag/sq." iso. fid. ell. mag.
j_r_i21cdoublearcsec J 21mag/sq." isophotal circular aperture radius.
j_m_i21cdoublemag J 21mag/sq." isophotal circular ap. magnitude.
j_msig_i21cdoublemag J 1-sigma uncertainty in 21mag/sq." iso. circ. mag.
j_flg_i21cint J confusion flag for 21mag/sq." iso. circ. mag.
h_r_i21cdoublearcsec H 21mag/sq." isophotal circular aperture radius.
h_m_i21cdoublemag H 21mag/sq." isophotal circular ap. magnitude.
h_msig_i21cdoublemag H 1-sigma uncertainty in 21mag/sq." iso. circ. mag.
h_flg_i21cint H confusion flag for 21mag/sq." iso. circ. mag.
k_r_i21cdoublearcsec K 21mag/sq." isophotal circular aperture radius.
k_m_i21cdoublemag K 21mag/sq." isophotal circular ap. magnitude.
k_msig_i21cdoublemag K 1-sigma uncertainty in 21mag/sq." iso. circ. mag.
k_flg_i21cint K confusion flag for 21mag/sq." iso. circ. mag.
r_j21fcdoublearcsec 21mag/sq." isophotal J fiducial circular ap. radius.
j_m_j21fcdoublemag J 21mag/sq." isophotal fiducial circ. ap. mag.
j_msig_j21fcdoublemag J 1-sigma uncertainty in 21mag/sq." iso.fid.circ.mag.
j_flg_j21fcint J confusion flag for 21mag/sq." iso. fid. circ. mag.
h_m_j21fcdoublemag J confusion flag for 21mag/sq." iso. fid. circ. mag.
h_msig_j21fcdoublemag H 1-sigma uncertainty in 21mag/sq." iso.fid.circ.mag.
h_flg_j21fcint
k_m_j21fcdoublemag H confusion flag for 21mag/sq." iso. fid. circ. mag.
k_msig_j21fcdoublemag K 1-sigma uncertainty in 21mag/sq." iso.fid.circ.mag.
k_flg_j21fcint K confusion flag for 21mag/sq." iso. fid. circ. mag.
j_m_5doublemag J 5 arcsec radius circular aperture magnitude.
j_msig_5doublemag J 1-sigma uncertainty in 5 arcsec circular ap. mag.
j_flg_5int J confusion flag for 5 arcsec circular ap. mag.
h_m_5doublemag H 5 arcsec radius circular aperture magnitude.
h_msig_5doublemag H 1-sigma uncertainty in 5 arcsec circular ap. mag.
h_flg_5int H confusion flag for 5 arcsec circular ap. mag.
k_m_5doublemag K 5 arcsec radius circular aperture magnitude.
k_msig_5doublemag K 1-sigma uncertainty in 5 arcsec circular ap. mag.
k_flg_5int K confusion flag for 5 arcsec circular ap. mag.
j_m_7doublemag J 7 arcsec radius circular aperture magnitude.
j_msig_7doublemag J 1-sigma uncertainty in 7 arcsec circular ap. mag.
j_flg_7int J confusion flag for 7 arcsec circular ap. mag.
h_m_7doublemag H 7 arcsec radius circular aperture magnitude.
h_msig_7doublemag H 1-sigma uncertainty in 7 arcsec circular ap. mag.
h_flg_7int H confusion flag for 7 arcsec circular ap. mag.
k_m_7doublemag K 7 arcsec radius circular aperture magnitude.
k_msig_7doublemag K 1-sigma uncertainty in 7 arcsec circular ap. mag.
k_flg_7int K confusion flag for 7 arcsec circular ap. mag.
j_m_10doublemag J 10 arcsec radius circular aperture magnitude.
j_msig_10doublemag J 1-sigma uncertainty in 10 arcsec circular ap. mag.
j_flg_10int J confusion flag for 10 arcsec circular ap. mag.
h_m_10doublemag H 10 arcsec radius circular aperture magnitude.
h_msig_10doublemag H 1-sigma uncertainty in 10 arcsec circular ap. mag.
h_flg_10int H confusion flag for 10 arcsec circular ap. mag.
k_m_10doublemag K 10 arcsec radius circular aperture magnitude.
k_msig_10doublemag K 1-sigma uncertainty in 10 arcsec circular ap. mag.
k_flg_10int K confusion flag for 10 arcsec circular ap. mag.
j_m_15doublemag J 15 arcsec radius circular aperture magnitude.
j_msig_15doublemag J 15 arcsec radius circular aperture magnitude.
j_flg_15int J confusion flag for 15 arcsec circular ap. mag.
h_m_15doublemag H 15 arcsec radius circular aperture magnitude.
h_msig_15doublemag H 1-sigma uncertainty in 15 arcsec circular ap. mag.
h_flg_15int H confusion flag for 15 arcsec circular ap. mag.
k_m_15doublemag K 15 arcsec radius circular aperture magnitude.
k_msig_15doublemag K 1-sigma uncertainty in 15 arcsec circular ap. mag.
k_flg_15int K confusion flag for 15 arcsec circular ap. mag.
j_m_20doublemag J 20 arcsec radius circular aperture magnitude.
j_msig_20doublemag J 1-sigma uncertainty in 20 arcsec circular ap. mag.
j_flg_20int J confusion flag for 20 arcsec circular ap. mag.
h_m_20doublemag H 20 arcsec radius circular aperture magnitude.
h_msig_20doublemag H 1-sigma uncertainty in 20 arcsec circular ap. mag.
h_flg_20int H confusion flag for 20 arcsec circular ap. mag.
k_m_20doublemag K 20 arcsec radius circular aperture magnitude.
k_msig_20doublemag K 1-sigma uncertainty in 20 arcsec circular ap. mag.
k_flg_20int K confusion flag for 20 arcsec circular ap. mag.
j_m_25doublemag J 25 arcsec radius circular aperture magnitude.
j_msig_25doublemag J 1-sigma uncertainty in 25 arcsec circular ap. mag.
j_flg_25int J confusion flag for 25 arcsec circular ap. mag.
h_m_25doublemag H 25 arcsec radius circular aperture magnitude.
h_msig_25doublemag H 1-sigma uncertainty in 25 arcsec circular ap. mag.
h_flg_25int H confusion flag for 25 arcsec circular ap. mag.
k_m_25doublemag K 25 arcsec radius circular aperture magnitude.
k_msig_25doublemag K 1-sigma uncertainty in 25 arcsec circular ap. mag.
k_flg_25int K confusion flag for 25 arcsec circular ap. mag.
j_m_30doublemag J 30 arcsec radius circular aperture magnitude.
j_msig_30doublemag J 1-sigma uncertainty in 30 arcsec circular ap. mag.
j_flg_30int J confusion flag for 30 arcsec circular ap. mag.
h_m_30doublemag H 30 arcsec radius circular aperture magnitude.
h_msig_30doublemag H 1-sigma uncertainty in 30 arcsec circular ap. mag.
h_flg_30int H confusion flag for 30 arcsec circular ap. mag.
k_m_30doublemag K 30 arcsec radius circular aperture magnitude.
k_msig_30doublemag K 1-sigma uncertainty in 30 arcsec circular ap. mag.
k_flg_30int K confusion flag for 30 arcsec circular ap. mag.
j_m_40doublemag J 40 arcsec radius circular aperture magnitude.
j_msig_40doublemag J 1-sigma uncertainty in 40 arcsec circular ap. mag.
j_flg_40int J confusion flag for 40 arcsec circular ap. mag.
h_m_40doublemag H 40 arcsec radius circular aperture magnitude.
h_msig_40doublemag H 1-sigma uncertainty in 40 arcsec circular ap. mag.
h_flg_40int H confusion flag for 40 arcsec circular ap. mag.
k_m_40doublemag K 40 arcsec radius circular aperture magnitude.
k_msig_40doublemag K 1-sigma uncertainty in 40 arcsec circular ap. mag.
k_flg_40int K confusion flag for 40 arcsec circular ap. mag.
j_m_50doublemag J 50 arcsec radius circular aperture magnitude.
j_msig_50doublemag J 1-sigma uncertainty in 50 arcsec circular ap. mag.
j_flg_50int J confusion flag for 50 arcsec circular ap. mag.
h_m_50doublemag H 50 arcsec radius circular aperture magnitude.
h_msig_50doublemag H 1-sigma uncertainty in 50 arcsec circular ap. mag.
h_flg_50int H confusion flag for 50 arcsec circular ap. mag.
k_m_50doublemag K 50 arcsec radius circular aperture magnitude.
k_msig_50doublemag K 1-sigma uncertainty in 50 arcsec circular ap. mag.
k_flg_50int K confusion flag for 50 arcsec circular ap. mag.
j_m_60doublemag J 60 arcsec radius circular aperture magnitude.
j_msig_60doublemag J 1-sigma uncertainty in 60 arcsec circular ap. mag.
j_flg_60int J confusion flag for 60 arcsec circular ap. mag.
h_m_60doublemag H 60 arcsec radius circular aperture magnitude.
h_msig_60doublemag H 1-sigma uncertainty in 60 arcsec circular ap. mag.
h_flg_60int H confusion flag for 60 arcsec circular ap. mag.
k_m_60doublemag K 60 arcsec radius circular aperture magnitude.
k_msig_60doublemag K 1-sigma uncertainty in 60 arcsec circular ap. mag.
k_flg_60int K confusion flag for 60 arcsec circular ap. mag.
j_m_70doublemag J 70 arcsec radius circular aperture magnitude.
j_msig_70doublemag J 1-sigma uncertainty in 70 arcsec circular ap. mag.
j_flg_70int J confusion flag for 70 arcsec circular ap. mag.
h_m_70doublemag H 70 arcsec radius circular aperture magnitude.
h_msig_70doublemag H 1-sigma uncertainty in 70 arcsec circular ap. mag.
h_flg_70int H confusion flag for 70 arcsec circular ap. mag.
k_m_70doublemag K 70 arcsec radius circular aperture magnitude.
k_msig_70doublemag K 1-sigma uncertainty in 70 arcsec circular ap. mag
k_flg_70int K confusion flag for 70 arcsec circular ap. mag.
j_m_sysdoublemag J system photometry magnitude.
j_msig_sysdoublemag J 1-sigma uncertainty in system photometry mag.
h_m_sysdoublemag H system photometry magnitude.
h_msig_sysdoublemag H 1-sigma uncertainty in system photometry mag.
k_m_sysdoublemag K system photometry magnitude.
k_msig_sysdoublemag K 1-sigma uncertainty in system photometry mag.
sys_flgint system flag: 0=no system, 1=nearby galaxy flux incl. in mag.
contam_flgint contamination flag: 0=no stars, 1=stellar flux incl. in mag.
j_5sig_badouble J minor/major axis ratio fit to the 5-sigma isophote.
j_5sig_phiintdeg J angle to 5-sigma major axis (E of N).
h_5sig_badouble H minor/major axis ratio fit to the 5-sigma isophote.
h_5sig_phiintarcsec H angle to 5-sigma major axis (E of N).
k_5sig_badouble K minor/major axis ratio fit to the 5-sigma isophote.
k_5sig_phiintarcsec K angle to 5-sigma major axis (E of N).
j_d_areaint J 5-sigma to 3-sigma differential area.
j_perc_dareaint J 5-sigma to 3-sigma percent area change.
h_d_areaint H 5-sigma to 3-sigma differential area.
h_perc_dareaint H 5-sigma to 3-sigma percent area change.
k_d_areaint K 5-sigma to 3-sigma differential area.
k_perc_dareaint K 5-sigma to 3-sigma percent area change.
j_bisym_ratdouble J bi-symmetric flux ratio.
j_bisym_chidouble J bi-symmetric cross-correlation chi.
h_bisym_ratdouble H bi-symmetric flux ratio.
h_bisym_chidouble H bi-symmetric cross-correlation chi.
k_bisym_ratdouble K bi-symmetric flux ratio.
k_bisym_chidouble K bi-symmetric cross-correlation chi.
j_sh0double J ridge shape (LCSB: BSNR limit).
j_sig_sh0double J ridge shape sigma (LCSB: B2SNR limit).
h_sh0double H ridge shape (LCSB: BSNR limit).
h_sig_sh0double H ridge shape sigma (LCSB: B2SNR limit).
k_sh0double K ridge shape (LCSB: BSNR limit).
k_sig_sh0double K ridge shape (LCSB: BSNR limit).
j_sc_mxdndouble J mxdn (score) (LCSB: BSNR - block/smoothed SNR).
j_sc_shdouble J shape (score).
j_sc_wshdouble J wsh (score) (LCSB: PSNR - peak raw SNR).
j_sc_r23double J r23 (score) (LCSB: TSNR - integrated SNR for r=15).
j_sc_1mmdouble J 1st moment (score) (LCSB: super blk 2,4,8 SNR).
j_sc_2mmdouble J 2nd moment (score) (LCSB: SNRMAX - super SNR max).
j_sc_vintdouble J vint (score).
j_sc_r1double J r1 (score).
j_sc_mshdouble J r1 (score).
h_sc_mxdndouble H mxdn (score) (LCSB: BSNR - block/smoothed SNR).
h_sc_shdouble H shape (score).
h_sc_wshdouble H wsh (score) (LCSB: PSNR - peak raw SNR).
h_sc_r23double H r23 (score) (LCSB: TSNR - integrated SNR for r=15).
h_sc_1mmdouble H 1st moment (score) (LCSB: super blk 2,4,8 SNR).
h_sc_2mmdouble H 2nd moment (score) (LCSB: SNRMAX - super SNR max).
h_sc_vintdouble H vint (score).
h_sc_r1double H r1 (score).
h_sc_mshdouble H median shape score.
k_sc_mxdndouble K mxdn (score) (LCSB: BSNR - block/smoothed SNR).
k_sc_shdouble K shape (score).
k_sc_wshdouble K wsh (score) (LCSB: PSNR - peak raw SNR).
k_sc_r23double K r23 (score) (LCSB: TSNR - integrated SNR for r=15).
k_sc_1mmdouble K 1st moment (score) (LCSB: super blk 2,4,8 SNR).
k_sc_2mmdouble K 2nd moment (score) (LCSB: SNRMAX - super SNR max).
k_sc_vintdouble K vint (score).
k_sc_r1double K r1 (score).
k_sc_mshdouble K median shape score.
j_chif_ellfdouble J % chi-fraction for elliptical fit to 3-sig isophote.
k_chif_ellfdouble K % chi-fraction for elliptical fit to 3-sig isophote.
ellfit_flgint ellipse fitting contamination flag.
sup_chif_ellfdouble super-coadd % chi-fraction for ellip. fit to 3-sig isophote.
n_blankint number of blanked source records.
n_subint number of subtracted source records.
bl_sub_flgint blanked/subtracted src description flag.
id_flgint type/galaxy ID flag (0=non-catalog, 1=catalog, 2=LCSB).
id_catstring matched galaxy's catalog name.
fg_flgstring flux-growth convergence flag.
blk_facint LCSB blocking factor (1, 2, 4, 8).
dup_srcint Duplicate source flag.
use_srcint Use source flag.
proxdoublearcsec Proximity.
pxpaintdeg The position angle on the sky of the vector from the source to the nearest neighbor in the PSC, in degrees East of North.
pxcntrint ext_key value of nearest XSC source.
dist_edge_nsintarcsec The distance from the source to the nearest North or South scan edge.
dist_edge_ewintarcsec The distance from the source to the nearest East or West scan edge.
dist_edge_flgstring flag indicating which edges ([n|s][e|w]) are nearest to src.
pts_keyint key to point source data DB record.
mp_keyint key to minor planet prediction DB record.
night_keyint key to night data record in "scan DB".
scan_keyint key to scan data record in "scan DB".
coadd_keyint key to coadd data record in "scan DB".
hemischar hemisphere (N/S) of observation. "n" = North/Mt. Hopkins; "s" = South/CTIO.
datedateTimeyyyy-mm-dd The observation reference date for this source expressed in ISO standard format. (YYYY-MM-DD)
scanint scan number (unique within date).
coaddint 3-digit coadd number (unique within scan).
idint source ID number (unique within scan, coadd).
x_coadddoublearcsec x (cross-scan) position (coadd coord.).
y_coadddoublearcsec y (in-scan) position (coadd coord.).
j_subst2double J residual background #2 (score).
h_subst2double H residual background #2 (score).
k_subst2double K residual background #2 (score).
j_backdouble J coadd median background.
h_backdouble H coadd median background.
k_backdouble K coadd median background.
j_resid_anndoubleDN J residual annulus background median.
h_resid_anndoubleDN H residual annulus background median.
k_resid_anndoubleDN K residual annulus background median.
j_bndg_perintarcsec J banding Fourier Transf. period on this side of coadd.
j_bndg_ampdoubleDN J banding maximum FT amplitude on this side of coadd.
h_bndg_perintarcsec H banding Fourier Transf. period on this side of coadd.
h_bndg_ampdoubleDN H banding maximum FT amplitude on this side of coadd.
k_bndg_perintarcsec K banding Fourier Transf. period on this side of coadd.
k_bndg_ampdoubleDN K banding maximum FT amplitude on this side of coadd.
j_seetrackdouble J band seetracking score.
h_seetrackdouble H band seetracking score.
k_seetrackdouble K band seetracking score.
ext_keyint entry counter (key) number (unique within table).

Table twomass_scn

Scan Working Data (70,712 survey mode scans).

ColumnTypeUnitsUCDErrorDescriptionLinks
scan_keyintThe unique identification number for this scan.
hemischarObservatory from which data were obtained: "n" = north = Mt. Hopkins, "s" = south = Cerro Tololo.
datecharyyyy-mm-ddThe observation reference date for this scan expressed in ISO standard format. (YYYY-MM-DD)
scanintScan number (unique within date).
tileintTile identification number.
rafloatdegRight ascension of scan center for equinox J2000.
declfloatdegDeclination of scan center for equinox J2000.
glonfloatdegGalactic longitude of scan center, as computed from ra and dec above.
glatfloatdegGalactic latitude of scan center, as computed from ra and dec above.
ra_1floatdegJ2000 right ascension of the eastern corner at start of scan.
dec_1floatdegJ2000 declination of the eastern corner at start of scan.
ra_2floatdegJ2000 right ascension of the western corner at start of scan.
dec_2floatdegJ2000 declination of the western corner at start of scan.
ra_3floatdegJ2000 right ascension of the eastern corner at end of scan.
dec_3floatdegJ2000 declination of the eastern corner at end of scan.
ra_4floatdegJ2000 right ascension of the western corner at end of scan.
dec_4floatdegJ2000 declination of the western corner at end of scan.
sdcharScanning direction: "n" = north-going, "s" = south-going.
qualintQuality score for scan.
hglintSpecial flag indicating whether or not this scan has a single-frame H-band electronic glitch.
cldintSpecial flag indicating whether or not a cloud was found in the scan after comparison of its photometry to that of overlapping scans in the database.
xphintSpecial flag indicating whether or not another photometric problem, not obviously cloud related, was found in the scan after comparing its photometry to that of overlapping scans.
anomintSpecial flag indicating whether or not an unusual problem was found in the Atlas Images for this scan.
utfloathrUniversal Time (UT) at beginning of scan.
jdatefloatJulian daysJulian Date at beginning of scan.
airmfloatAirmass at beginning of scan.
zdfloatdegScan's distance from the zenith at beginning of scan.
hafloathrHour angle at beginning of scan.
rhintpercentsRelative humidity of telescope enclosure at beginning of scan.
air_tempfloatdegCAir temperature at beginning of scan.
tel_tempfloatdegCTelescope girdle temperature at beginning of scan.
focusintFocus setting of telescope at beginning of scan.
hryintFlag indicating the H-band array configuration for the camera.
c_stratintFlag indicating the calibration strategy for this night's data.
j_zp_apfloatmagPhotometric zero-point for J-band aperture photometry.
h_zp_apfloatmagPhotometric zero-point for H-band aperture photometry.
k_zp_apfloatmagPhotometric zero-point for Ks-band aperture photometry.
h_zperr_apfloatmagRMS-error of zero-point for H-band aperture photometry
k_zperr_apfloatmagRMS-error of zero-point for Ks-band aperture photometry
j_n_snr10intNumber of point sources at J-band with SNR>10 (instrumental mag lover or =15.8)
h_n_snr10intNumber of point sources at H-band with SNR>10 (instrumental mag lover or =15.1)
k_n_snr10intNumber of point sources at Ks-band with SNR>10 (instrumental mag lover or =14.3)
n_extintNumber of regular extended sources detected in scan.
j_shape_avgfloatJ-band average seeing shape for scan.
h_shape_avgfloatH-band average seeing shape for scan.
k_shape_avgfloatKs-band average seeing shape for scan.
j_shape_rmsfloatRMS-error of J-band average seeing shape.
h_shape_rmsfloatRMS-error of H-band average seeing shape.
k_shape_rmsfloatRMS-error of Ks-band average seeing shape.
j_2mratfloatJ-band average 2nd image moment ratio.
h_2mratfloatH-band average 2nd image moment ratio.
k_2mratfloatKs-band average 2nd image moment ratio.
j_pspfloatJ-band photometric sensitivity paramater (PSP).
h_pspfloatH-band photometric sensitivity paramater (PSP).
k_pspfloatKs-band photometric sensitivity paramater (PSP).
j_pts_noisefloatBase-10 logarithm of the mode of the noise distribution for all point source detections in the scan, where the noise is estimated from the measured J-band photometric errors and is expressed in units of mJy.
h_pts_noisefloatBase-10 logarithm of the mode of the noise distribution for all point source detections in the scan, where the noise is estimated from the measured H-band photometric errors and is expressed in units of mJy.
k_pts_noisefloatBase-10 logarithm of the mode of the noise distribution for all point source detections in the scan, where the noise is estimated from the measured Ks-band photometric errors and is expressed in units of mJy.
j_msnr10floatmagThe estimated J-band magnitude at which SNR=10 is achieved for this scan.
h_msnr10floatmagThe estimated H-band magnitude at which SNR=10 is achieved for this scan.
k_msnr10floatmagThe estimated Ks-band magnitude at which SNR=10 is achieved for this scan.
rel0intFlag indicating whether the scan is contained in the TWOMASS Sampler Release.
rel1intFlag indicating whether the scan is contained in the TWOMASS First Incremental Data Release (IDR1).
rel2intFlag indicating whether the scan is contained in the TWOMASS Second Incremental Data Release (IDR2).

Table gsc23

The GSC2.3.2 Catalogue (945598527 objects for export version). The GSC II is an all-sky catalog based on 1" resolution scans of the photographic Sky Survey plates, at two epochs and three bandpasses, from the Palomar and UK Schmidt telescopes (DSS). Positions, magnitudes, and classifications are produced for all objects on each plate. The GSC2.3 has no magnitude limit. The parameters of the bright objects, overexposed on the Schmidt plates, are taken from the Tycho-2 (I/259) catalog. Reference: The Second Generation Guide Star Catalog : Description and Properties Lasker et al 2008 AJ 136,735

ColumnTypeUnitsUCDErrorDescriptionLinks
gsc2idstringcharmeta.id;meta.main[NS0-9A-Z] Identification of the object
gsc1idstringcharmeta.id;meta.mainIdentification of object in GSC Version 1
htm6stringcharobs.field[NS0-3] HTM-6 designation as in GSC2.2
radoubledegpos.eq.ra;meta.main(ra) Right ascension (J2000)
decdoubledegpos.eq.dec;meta.main(dec) Declination (J2000)
ra_epsfloatarcsecstat.error;pos.eq.raMean error on RAdeg, multiplied by cos(delta)
dec_epsfloatarcsecstat.error;pos.eq.decMean error on DECdeg
mean_epochfloatyrtime.epochEpoch of the mean
ra_pmfloatmas/yrpos.pm;pos.eq.raProper motion in RA, multiplied by cos(delta)
dec_pmfloatmas/yrpos.pm;pos.eq.decProper motion in DEC
ra_pm_errfloatmasstat.errorMean error on proper motion in RA
dec_pm_errfloatmasstat.errorMean error on proper motion in DEC
delta_epochfloatyrtime.epochEpoch of the mean
f_magfloatmagphot.mag;em.opt.R(f_mag) Magnitude in F photographic band (red)
f_mag_errfloatmagstat.error;phot.mag;em.opt.R(f_mag_err) Mean error on fmag
f_mag_codeintmeta.note(f_mag_code) Coded emulsion / bandpass / filter
j_magfloatmagphot.mag;em.opt.B(j_mag) Magnitude in Bj photographic band (blue)
j_mag_errfloatmagstat.error;phot.mag;em.opt.B(j_mag_err) Mean error on jmag
j_mag_codeintmeta.note(j_mag_code) Coded emulsion / bandpass / filter
v_magfloatmagphot.mag;em.opt.V(v_mag) Magnitude in V photographic band (green)
v_mag_errfloatmagstat.error;phot.mag;em.opt.V(v_mag_err) Mean error on vmag
v_mag_codeintmeta.note(v_mag_code) Coded emulsion / bandpass / filter
n_magfloatmagphot.mag;em.opt.IR.8-15um(n_mag) Magnitude in N photographic band (0.8um)
n_mag_errfloatmagstat.error;phot.mag;em.opt.IR.8-15um(n_mag_err) Mean error on nmag
n_mag_codeintmeta.note(n_mag_code) Coded emulsion / bandpass / filter
u_magfloatmagphot.mag;em.opt.U(u_mag) Magnitude in U band (Johnson)
u_mag_errfloatmagstat.error;phot.mag;em.opt.U(u_mag_err) Mean error on umag
u_mag_codeintmeta.note(u_mag_code) Coded emulsion / bandpass / filter
b_magfloatmagphot.mag;em.opt.B(b_mag) Magnitude in B band (Johnson blue)
b_mag_errfloatmagstat.error;phot.mag;em.opt.B(b_mag_err) Mean error on bmag
b_mag_codeintmeta.note(b_mag_code) Coded emulsion / bandpass / filter
classintmeta.code[0,5] Object class
source_statusintmeta.code.errorSource status flag
multobjcharmeta.code[M] 'M' for multiple object
size_afloatpixphys.angSize;srcSemi-major axis of fitting ellipse
eccenfloatsrc.orbital.eccentricityEccentricity of fitting ellipse
a_pafloatdegpos.posAngPosition angle (N->E) of fitting ellipse

Table gaia

GaiaSource DR1 Catalog. This table has an entry for every Gaia observed source as listed in the Main Dat abase accumulating catalogue version from which the catalogue release has been g enerated. It contains the basic source parameters, that is only final data (no e poch data) and no spectra (neither final nor epoch).

ColumnTypeUnitsUCDErrorDescriptionLinks
solution_idlongmeta.id;meta.versionAll Gaia data processed by the Data Processing and Analysis Consortium comes tagged with a solution identifier. This is a numeric field attached to each table row that can be used to unequivocally identify the version of all the subsystems that where used in the generation of the data as well as the input data used. It is mainly for internal DPAC use but is included in the published data releases to enable end users to examine the provenance of processed data products. To decode a given solution ID visit.
source_idlongmeta.id;meta.main A unique single numerical identifier of the source. For the contents of Gaia DR1, which does not include Solar System objects, the source ID consists 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(sourceId / 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 - 32 split into: - a 25 bit running number in bits 8-32;the running numbers are defined to be positive, i.e. ver zero (except in the case of forced empty windows) - a 7-bit component number in bits 1-7 - 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).
random_indexlongmeta.codeRandom index which can be used to select smaller subsets of the data that are still representative. The column contains a random permutation of the numbers from 0 to N-1, where N is the number of rows. The random index can be useful for validation (testing on 10 different random subsets), visualization (displaying 1% of the data), and statistical exploration of the data, without the need to download all the data.
ref_epochdoubleTime[Julian Years]meta.ref;time.epochReference epoch to which the astrometic source parameters are refer red, expressed as a Julian Year in TCB.
radoubledegpos.eq.ra;meta.main Barycentric right ascension \alpha of the source in ICRS at the reference epoch refEpoch
ra_errordoubleAngle[mas]stat.error;pos.eq.ra Standard error \sigma_{\alpha *} \equiv \sigma_\alpha\cos\delta of the right ascension of the source in ICRS at the reference epoch refEpoch
decdoubledegpos.eq.dec;meta.main Barycentric declination \delta of the source in ICRS at the reference epoch refEpoch
dec_errordoubleAngle[mas]stat.error;pos.eq.dec Standard error \sigma_\delta of the declination of the source in ICRS at the reference epoch refEpoch
parallaxdoubleAngle[mas]pos.parallax Absolute barycentric stellar parallax \varpi of the soure at the reference epoch refEpoch
parallax_errordoubleAngle[mas]stat.error;pos.parallax Standard error \sigma_\varpi of the stellar parallax at the referen ceepoch refEpoch
pmradoubleAngular Velocity[mas/year]pos.pm;pos.eq.ra Proper motion in right ascension \mu_{\alpha *} of the source in IC RS at the reference epoch refEpoch. This is the projection of the proper motion vector in the direction of increasing right ascension.
pmra_errordoubleAngular Velocity[mas/year]stat.error;pos.pm;pos.eq.ra Standard error \sigma_{\mu\alpha *} of the proper motion vector in right ascension at the reference epoch refEpoch
pmdecdoubleAngular Velocity[mas/year]pos.pm;pos.eq.dec Proper motion in declination \mu_\delta of the source at the reference epoch refEpoch. This is the projection of the proper motion vector in the direction of increasing declination.
pmdec_errordoubleAngular Velocity[mas/year]stat.error;pos.pm;pos.eq.dec Standard error \sigma_{\mu\delta} of the proper motion in declination at the reference epoch refEpoch
ra_dec_corrfloatDimensionlessstat.correlation Correlation between right ascension and declination, in dimensionless units [-1:+1]
ra_parallax_corrfloatDimensionlessstat.correlation Correlation between right ascension and parallax, in dimensionless units [-1:+1]
ra_pmra_corrfloatDimensionlessstat.correlation Correlation between right ascension and proper motion in right ascension, in dimensionless units [-1:+1]
ra_pmdec_corrfloatDimensionlessstat.correlation Correlation between right ascension and proper motion in declination, in dimensionless units [-1:+1]
dec_parallax_corrfloatDimensionlessstat.correlation Correlation between declination and parallax, in dimensionless units [-1:+1]
dec_pmra_corrfloatDimensionlessstat.correlation Correlation between declination and proper motion in right ascension, in dimensionless units [-1:+1]
dec_pmdec_corrfloatDimensionlessstat.correlation Correlation between declination and proper motion in declination, in dimensionless units [-1:+1]
parallax_pmra_corrfloatDimensionlessstat.correlation Correlation between parallax and proper motion in right ascension, dimensionless units [-1:+1]
parallax_pmdec_corrfloatDimensionlessstat.correlation Correlation between parallax and proper motion in declination, in dimensionless units [-1:+1]
pmra_pmdec_corrfloatDimensionlessstat.correlation Correlation between proper motion in right ascension and proper motion in declination, in dimensionless units [-1:+1]
astrometric_n_obs_alintDimensionlessmeta.number Total number of AL observations (= CCD transits) used in the astrometric solution of the source, independent of their weight. Note that some observations may be strongly downweighted (see astrometricNBadObsAl).
astrometric_n_obs_acintDimensionlessmeta.number Total number of AC observations (= CCD transits) used in the astrometric solution of the source, independent of their weight. Note that some observations may be strongly downweighted (see astrometricNBadObsAc). Nearly all sources having G less than 13 will have AC observations from 2d windows, while fainter than that limit only \sim1% of stars are assigned 2d windows resulting in AC observations.
astrometric_n_good_obs_acintDimensionlessmeta.number Number of AC observations (= CCD transits) that were not strongly downweighted in the astrometric solution of the source. Strongly downweighted observations (with downweighting factor w less than 0.2) are instead counted in astrometricNBadObsAc. The sum of astrometricNGoodObsAc and astrometricNBadObsAc equals astrometricNObsAc, the total number of AC observations used in the astrometric solution of the source.
astrometric_n_bad_obs_alintDimensionlessmeta.number Number of AL observations (= CCD transits) that were strongly downweighted in the astrometric solution of the source, and therefore contributed little to the determination of the astrometric parameters. An observation is considered to be strongly downweighted if its downweighting factor w less than 0.2, which means that the absolute value of the astrometric residual exceeds 4.83 times the total uncertainty of the observation, calculated as the quadratic sum of the centroiding uncertainty, excess source noise, and excess attitude noise.
astrometric_n_bad_obs_acintDimensionlessmeta.number Number of AC observations (= CCD transits) that were strongly downweighted in the astrometric solution of the source, and therefore contributed little to the determination of the astrometric parameters. An observation is considered to be strongly downweighted if its downweighting factor w less than 0.2, which means that the absolute value of the astrometric residual exceeds 4.83 times the total uncertainty of the observation, calculated as the quadratic sum of the centroiding uncertainty, excess source noise, and excess attitude noise.
astrometric_delta_qfloatAngle[mas]stat.value In the TGAS solution \tt astrometricDeltaQ (\Delta Q) indicates the discrepancy between the Hipparcos proper motion and the TGAS proper motion. A large value of \tt deltaQ could indicate non-linear motion (e.g. n a binary). The precise definition is \Delta Q = \begin{bmatrix} \Delta\mu_{\alpha *} \and \Delta\mu_{\delta} \end{bmatrix} \left(\vec{C}_\text{pm,\,T}+\vec{C}_\text{pm,\,H}\right)^{-1} \begin{bmatrix} \Delta\mu_{\alpha *} \\ \Delta\mu_{\delta} \end{bmatrix} where \Delta\mu_{\alpha *} = \mu_{\alpha *,\rm T}-\mu_{\alpha *,\rm H}, \Delta\mu_{\delta} = \mu_{\delta,\rm T}-\mu_{\delta,\rm H}, with T and H indicating values from the Gaia DR1 (TGAS) solution and Hipparcos catalogue. \vec{C}_\text{pm,\,T} and \vec{C}_\text{pm,\,H} are the corresponding 2\times 2 covariance matrices. In order to compute \Delta Q the two sets of proper motions must use the same reference frame and the same reference epoch. Thus, the proper motion components as given in the Hipparcos catalogue were rotated to the Gaia DR1 reference frame, and then propagated to the Gaia reference epoch.
astrometric_excess_noisedoubleAngle[mas]stat.value This is the excess noise \epsilon_i of the source. It measures the disagreement, expressed as an angle, between the observations of a source and the best-fitting standard astrometric model (using five astrometric parameters). The assumed observational noise in each observation is quadratically increased by \epsilon_i in order to statistically match the residuals in the astrometric solution. A value of 0 signifies that the source is astrometrically well-behaved, i.e. that the residuals of the fit statistically agree with the assumed observational noise. A positive value signifies that the residuals are statistically larger than expected. The significance of \epsilon_i is given by \tt astrometricExcessNoiseSig (D). If D\le 2 then \epsilon_i is probably not significant, and the source may be astrometrically well-behaved even if \epsilon_i is large. The excess noise \epsilon_i may absorb all kinds of modelling errors that are not accounted for by the observational noise (image centroiding error) or the excess attitude noise. Such modelling errors include LSF and PSF calibration errors, geometric instrument calibration errors, and part of the high-frequency attitude noise. These modelling errors are particularly important in the early data releases, but should decrease as the astrometric modelling of the instrument and attitude improves over the years. Additionally, sources that deviate from the standard five-parameter astrometric model (e.g. n resolved binaries, exoplanet systems, etc.) may have positive \epsilon_i. Given the many other possible contributions to the excess noise, the user must study the empirical distributions of \epsilon_i and D to make sensible cutoffs before filtering out sources for their particular application. In Gaia DR1, the excess source noise has the same interpretation as described above for both the primary (TGAS) and secondary data sets. It measures the disagreement between the five-parameter model and the observations, augmented by the different priors used. Thus, in TGAS the excess noise may be increased if the proper motion seen during the 14 months of Gaia observations are not in agreement with the proper motion inferred from the Tycho-2/Gaia comparison. In the secondary solution the excess noise may be increased if the Gaia observations indicate a proper motion or parallax several times larger than the prior uncertainty. The excess source noise is further explained in Sects .6 and 5.1.2 of Lindegren et al. (2012). Lindegren, L., U. Lammers, D. Hobbs, MullaneW., U. Bastian, and J. Hernandez. 2012.The Astrometric Core Solution for the Gaia Mission. Overview of Models, Algorithms, and Software Implementation. Astronomy and Astrophysics 538 (February).
astrometric_excess_noise_sigdoubleAngle[mas]stat.value A dimensionless measure (D) of the significance of the calculated \ tt astrometricExcessNoise (\epsilon_i). A value D less than 2 indicates that the given \epsilon_i is probably significant. For good fits in the limit of a large number of observations, D should be zero in half of the cases and approximately follow the positive half of a normal distribution with zero mean and unit standard deviation for the other half. Consequently, D is expected to be greater than 2 for only a few percent of the sources with well-behaved astrometric solutions. In the early data releases \epsilon_i will however include instrument and attitude modelling errors that are statistically significant and could result in large values of \epsilon_i and D. The user must study the empirical distributions of these statistics and make sensible cutoffs before filtering out sources for their particular application. The excess noise significance is further explained in Sect. 1.2 of Lindegren et al. (2012). Lindegren, L., U. Lammers, D. Hobbs, MullaneW., U. Bastian, and J. Hernandez. 2012.The Astrometric Core Solution for the Gaia Mission. Overview of Models, Algorithms, and Software Implementation. Astronomy and Astrophysics 538 (February).
astrometric_primary_flagbooleanmeta.code Flag indicating if this source was used as a primary source (\tt true) or secondary source (\tt false). Only primary sources contribute to the estimation of attitude, calibration, and global parameters. The estimation of source parameters is otherwise done in exactly the same way for primary and secondary sources.
astrometric_relegation_factorfloatarith.factor Relegation factor of the source calculated as per Eq. 118) in Lindegren et al. (2012) used for the primary selection process. Lindegren, L., U. Lammers, D. Hobbs, MullaneW., U. Bastian, and J. Hernandez. 2012.The Astrometric Core Solution for the Gaia Mission. Overview of Models, Algorithms, and Software Implementation. Astronomy and Astrophysics 538 (February).
astrometric_weight_alfloatAngle[mas^-2]stat.weight;stat.mean Mean astrometric weight of the source in the AL direction The mean astrometric weight of the source is calculated as per Eq. \sigma =(119) in Lindegren et al. (2012). Lindegren, L., U. Lammers, D. Hobbs, MullaneW., U. Bastian, and J. Hernandez. 2012.The Astrometric Core Solution for the Gaia Mission. Overview of Models, Algorithms, and Software Implementation. Astronomy and Astrophysics 538 (February).
astrometric_priors_usedintmeta.number Type of prior used in the astrometric solution: - 0: No prior used - 1: Galaxy Bayesian Prior for parallax and proper motion - 2: Galaxy Bayesian Prior for parallax and proper motion relaxed by factor 10 - 3: Hipparcos prior for position - 4: Hipparcos prior for position and proper motion - 5: Tycho2 prior for position - 6: Quasar prior for proper motion The Galaxy Bayesian Prior is defined in , where it is denoted \sigma_{\varpi,F90} (for the parallax) and \sigma_{\mu,F90}={\cal R}\sigma_{\varpi,F90}, with {\cal R}=10r^{-1} (for proper motion). The Galaxy Bayesian Prior relaxed by a factor 10 is 10\sigma_{\varpi,F90} and 10\sigma_{\mu,F90}, respectively. For Gaia DR1 the only types of priors used are 2 (for the secondary data set), 3 (for the Hipparcos subset of the primary data set), or 5 (for the non-Hipparcos subset of the primary data set). Type 6 was used for internal calibration purposes and alignment of the reference frame, but the corresponding astrometric results are in general not published.
matched_observationsshortmeta.number This field indicates the number of observations (detection transits) that have been matched to a given source during the last internal crossmatch revision.
duplicated_sourcebooleanmeta.number During data processing, this source happened to been duplicated and one source only has been kept. This may indicate observational, cross-matching or processing problems, or stellar multiplicity, and probable astrometric or photometric problems in all cases. In DR1, for close doubles with separations below some 2 arcsec, truncated windows have not been processed, neither in astrometry and photometry. The transmitted window is centred on the brighter part of the acquired window, so the brighter component has a better chance to be selected, even when processing the fainter transit. If more than two images are contained in a window, the result of the image parameter determination is un-predictable in the sense that it might refer to either (or neither) image, and no consistency is assured.
scan_direction_strength_k1floatmeta.number The scanDirectionStrength and scanDirectionMean quantify the distribution of AL scan directions across the source. scanDirectionStrength[k-1] (k=1,2,3,4) is the absolute value of the trigonometric moments m_k=\langle\exp(ik\theta)\rangle, where \theta is the position angle of the scan and the mean value is taken over the nObs[0] AL observations contributing to the astrometric parameters of the source. \theta is defined in the usual astronomical sense: \theta=0 when the FoV is moving towards local North, and \theta=90^\circ towards local East. The scanDirectionStrength is a number between 0 and 1, where 0 means that the scan directions are well spread out in different directions, while 1 means that they are concentrated in a single direction (given by scanAngleMean). The different orders k are statistics of the scan directions modulo 360^\circ/k. For example, at first order (k=1), \theta=10^\circ and \theta=190^\circ count as different directions, but at second order (k=2) they are the same. Thus, scanDirectionStrength[0] is the degree of concentration when the sense of direction is taken into account, while scanDirectionStrength[1] is the degree of concentration without regard to the sense of direction. A large value of scanDirectionStrength[3] indicates that the scans are concentrated in two nearly orthogonal directions.
scan_direction_strength_k2floatmeta.number The scanDirectionStrength and scanDirectionMean quantify the distribution of AL scan directions across the source. scanDirectionStrength[k-1] (k=1,2,3,4) is the absolute value of the trigonometric moments m_k=\langle\exp(ik\theta)\rangle, where \theta is the position angle of the scan and the mean value is taken over the nObs[0] AL observations contributing to the astrometric parameters of the source. \theta is defined in the usual astronomical sense: \theta=0 when the FoV is moving towards local North, and \theta=90^\circ towards local East. The scanDirectionStrength is a number between 0 and 1, where 0 means that the scan directions are well spread out in different directions, while 1 means that they are concentrated in a single direction (given by scanAngleMean). The different orders k are statistics of the scan directions modulo 360^\circ/k. For example, at first order (k=1), \theta=10^\circ and \theta=190^\circ count as different directions, but at second order (k=2) they are the same. Thus, scanDirectionStrength[0] is the degree of concentration when the sense of direction is taken into account, while scanDirectionStrength[1] is the degree of concentration without regard to the sense of direction. A large value of scanDirectionStrength[3] indicates that the scans are concentrated in two nearly orthogonal directions.
scan_direction_strength_k3floatmeta.number The scanDirectionStrength and scanDirectionMean quantify the distribution of AL scan directions across the source. scanDirectionStrength[k-1] (k=1,2,3,4) is the absolute value of the trigonometric moments m_k=\langle\exp(ik\theta)\rangle, where \theta is the position angle of the scan and the mean value is taken over the nObs[0] AL observations contributing to the astrometric parameters of the source. \theta is defined in the usual astronomical sense: \theta=0 when the FoV is moving towards local North, and \theta=90^\circ towards local East. The scanDirectionStrength is a number between 0 and 1, where 0 means that the scan directions are well spread out in different directions, while 1 means that they are concentrated in a single direction (given by scanAngleMean). The different orders k are statistics of the scan directions modulo 360^\circ/k. For example, at first order (k=1), \theta=10^\circ and \theta=190^\circ count as different directions, but at second order (k=2) they are the same. Thus, scanDirectionStrength[0] is the degree of concentration when the sense of direction is taken into account, while scanDirectionStrength[1] is the degree of concentration without regard to the sense of direction. A large value of scanDirectionStrength[3] indicates that the scans are concentrated in two nearly orthogonal directions.
scan_direction_strength_k4floatmeta.number The scanDirectionStrength and scanDirectionMean quantify the distribution of AL scan directions across the source. scanDirectionStrength[k-1] (k=1,2,3,4) is the absolute value of the trigonometric moments m_k=\langle\exp(ik\theta)\rangle, where \theta is the position angle of the scan and the mean value is taken over the nObs[0] AL observations contributing to the astrometric parameters of the source. \theta is defined in the usual astronomical sense: \theta=0 when the FoV is moving towards local North, and \theta=90^\circ towards local East. The scanDirectionStrength is a number between 0 and 1, where 0 means that the scan directions are well spread out in different directions, while 1 means that they are concentrated in a single direction (given by scanAngleMean). The different orders k are statistics of the scan directions modulo 360^\circ/k. For example, at first order (k=1), \theta=10^\circ and \theta=190^\circ count as different directions, but at second order (k=2) they are the same. Thus, scanDirectionStrength[0] is the degree of concentration when the sense of direction is taken into account, while scanDirectionStrength[1] is the degree of concentration without regard to the sense of direction. A large value of scanDirectionStrength[3] indicates that the scans are concentrated in two nearly orthogonal directions.
scan_direction_mean_k1floatAngle[deg]meta.number The scanDirectionStrength and scanDirectionMean quantify the distribution of AL scan directions across the source. scanDirectionStrength[k-1] (k=1,2,3,4) is the absolute value of the trigonometric moments m_k=\langle\exp(ik\theta)\rangle, where \theta is the position angle of the scan and the mean value is taken over the nObs[0] AL observations contributing to the astrometric parameters of the source. \theta is defined in the usual astronomical sense: \theta=0 when the FoV is moving towards local North, and \theta=90^\circ towards local East. The scanDirectionStrength is a number between 0 and 1, where 0 means that the scan directions are well spread out in different directions, while 1 means that they are concentrated in a single direction (given by scanAngleMean). The different orders k are statistics of the scan directions modulo 360^\circ/k. For example, at first order (k=1), \theta=10^\circ and \theta=190^\circ count as different directions, but at second order (k=2) they are the same. Thus, scanDirectionStrength[0] is the degree of concentration when the sense of direction is taken into account, while scanDirectionStrength[1] is the degree of concentration without regard to the sense of direction. A large value of scanDirectionStrength[3] indicates that the scans are concentrated in two nearly orthogonal directions.
scan_direction_mean_k2floatAngle[deg]meta.number The scanDirectionStrength and scanDirectionMean quantify the distribution of AL scan directions across the source. scanDirectionStrength[k-1] (k=1,2,3,4) is the absolute value of the trigonometric moments m_k=\langle\exp(ik\theta)\rangle, where \theta is the position angle of the scan and the mean value is taken over the nObs[0] AL observations contributing to the astrometric parameters of the source. \theta is defined in the usual astronomical sense: \theta=0 when the FoV is moving towards local North, and \theta=90^\circ towards local East. The scanDirectionStrength is a number between 0 and 1, where 0 means that the scan directions are well spread out in different directions, while 1 means that they are concentrated in a single direction (given by scanAngleMean). The different orders k are statistics of the scan directions modulo 360^\circ/k. For example, at first order (k=1), \theta=10^\circ and \theta=190^\circ count as different directions, but at second order (k=2) they are the same. Thus, scanDirectionStrength[0] is the degree of concentration when the sense of direction is taken into account, while scanDirectionStrength[1] is the degree of concentration without regard to the sense of direction. A large value of scanDirectionStrength[3] indicates that the scans are concentrated in two nearly orthogonal directions.
scan_direction_mean_k3floatAngle[deg]meta.number The scanDirectionStrength and scanDirectionMean quantify the distribution of AL scan directions across the source. scanDirectionStrength[k-1] (k=1,2,3,4) is the absolute value of the trigonometric moments m_k=\langle\exp(ik\theta)\rangle, where \theta is the position angle of the scan and the mean value is taken over the nObs[0] AL observations contributing to the astrometric parameters of the source. \theta is defined in the usual astronomical sense: \theta=0 when the FoV is moving towards local North, and \theta=90^\circ towards local East. The scanDirectionStrength is a number between 0 and 1, where 0 means that the scan directions are well spread out in different directions, while 1 means that they are concentrated in a single direction (given by scanAngleMean). The different orders k are statistics of the scan directions modulo 360^\circ/k. For example, at first order (k=1), \theta=10^\circ and \theta=190^\circ count as different directions, but at second order (k=2) they are the same. Thus, scanDirectionStrength[0] is the degree of concentration when the sense of direction is taken into account, while scanDirectionStrength[1] is the degree of concentration without regard to the sense of direction. A large value of scanDirectionStrength[3] indicates that the scans are concentrated in two nearly orthogonal directions.
scan_direction_mean_k4floatAngle[deg]meta.number The scanDirectionStrength and scanDirectionMean quantify the distribution of AL scan directions across the source. scanDirectionStrength[k-1] (k=1,2,3,4) is the absolute value of the trigonometric moments m_k=\langle\exp(ik\theta)\rangle, where \theta is the position angle of the scan and the mean value is taken over the nObs[0] AL observations contributing to the astrometric parameters of the source. \theta is defined in the usual astronomical sense: \theta=0 when the FoV is moving towards local North, and \theta=90^\circ towards local East. The scanDirectionStrength is a number between 0 and 1, where 0 means that the scan directions are well spread out in different directions, while 1 means that they are concentrated in a single direction (given by scanAngleMean). The different orders k are statistics of the scan directions modulo 360^\circ/k. For example, at first order (k=1), \theta=10^\circ and \theta=190^\circ count as different directions, but at second order (k=2) they are the same. Thus, scanDirectionStrength[0] is the degree of concentration when the sense of direction is taken into account, while scanDirectionStrength[1] is the degree of concentration without regard to the sense of direction. A large value of scanDirectionStrength[3] indicates that the scans are concentrated in two nearly orthogonal directions.
phot_g_n_obsintmeta.number Number of observations (CCD transits) that contributed to the G mean flux and mean flux error.
phot_g_mean_fluxdoubleFlux[e-/s]phot.flux;stat.mean;em.opt Mean flux in the G-band.
phot_g_mean_flux_errordoubleFlux[e-/s]stat.error;phot.flux;stat.mean;em.opt Error on the mean flux in the G-band.
phot_g_mean_magdoubleMagnitude[mag]phot.mag;stat.mean;em.opt Mean magnitude in the G band. This is computed from the G-band mean flux applying the magnitude zero-point in the Vega scale.
phot_variable_flagstringcharmeta.code;src.var Flag indicating if variability was identified in the photometric G band: - source not processed and/or exported to catalogue - Source not identified as variable - source identified and processed as variable, see tables PhotVariableSummary, PhotVariableTimeSeriesGfov, PhotVariableTimeSeriesGfovStatisticalParameters, and Cepheid or Rrlyrae for more details. Note that for this data release only a small subset of (variable) sources was processed and/or exported, so for many (known) variable sources this flag is set to NOT AVAILABLE. No CONSTANT sources were exported either.
ldoubleAngle[deg]pos.galactic.lon Galactic Longitude of the object at reference epoch refEpoch, see ESA, 1997, The Hipparcos and Tycho Catalogues ESA SP-1200, Volume 1, Section 1.5.3, for the conversion details.
bdoubleAngle[deg]pos.galactic.lat Galactic Latitude of the object at reference epoch refEpoch 1997, The Hipparcos and Tycho Catalogues ESA SP-1200, Volume 1, Section 1.5.3, for the conversion details.
ecl_londoubleAngle[deg]pos.ecliptic.lon Ecliptic Longitude of the object at reference epoch refEpoch, see ESA 1997, The Hipparcos and Tycho Catalogues ESA SP-1200, Volume 1, Section 1.5.3, for the conversion details.
ecl_latdoubleAngle[deg]pos.ecliptic.lon Ecliptic Latitude of the object at reference epoch refEpoch, see ESA 1997, The Hipparcos and Tycho Catalogues ESA SP-1200, Volume 1, Section 1.5.3, for the conversion details.