Table information for 'tgas.main'

General

This table is available for ADQL queries and through the TAP endpoint.

Resource Description: This table is a subset of GaiaSource comprising those stars in the Hipparcos and Tycho-2 Catalogues for which a full 5-parameter astrometric solution has been possible in Gaia Data Release 1. This is possible because the early Hipparcos epoch positions break some degeneracies due to the limited Gaia time coverage. This table contains a substantial fraction of the around 2.5 million stars in the Hipparcos and Tycho-2 catalogue. Many stars have been excluded due to several reasons, such as saturation, cross-match errors or bad astrometric solution. All rows have Gaia solution id 1635378410781933568.

For a list of all services and tables belonging to this table's resource, see Information on resource 'TGAS catalogue'

Citing this table

Reference the Table

To cite the table as such, we suggest the following BibTeX entry:

@MISC{vo:tgas_main,
  year=2016,
  title={{TGAS} catalogue},
  author={{GAIA} Collaboration},
  url={http://dc.zah.uni-heidelberg.de/tableinfo/tgas.main},
  howpublished={{VO} resource provided by the {GAVO} Data Center}
}

Fields

Sorted by DB column index. [Sort alphabetically]

NameTable Head DescriptionUnitUCD
source_id Source Id Unique source identifier [Note id] N/A meta.id;meta.main
ra RA (ICRS) Barycentric Right Ascension in ICRS at ref_epoch deg pos.eq.ra;meta.main
dec Dec (ICRS) Barycentric Declination in ICRS at ref_epoch deg pos.eq.dec;meta.main
ra_error Err. RA Standard error of ra (with cos δ applied). mas stat.error;pos.eq.ra
dec_error Err. Dec Standard error of dec mas stat.error;pos.eq.dec
l l Galactic longitude (converted from ra, dec) deg pos.galactic.lon
b b Galactic latitude (converted from ra, dec) deg pos.galactic.lat
pmra µ(RA) Proper motion in right ascension of the source in ICRS at ref_epoch. This is the projection of the proper motion vector in the direction of increasing right ascension. mas/yr pos.pm;pos.eq.ra
pmdec µ(Dec) Proper motion in declination at ref_epoch. mas/yr pos.pm;pos.eq.dec
pmra_error Err. PM(RA) Standard error of pmra mas/yr stat.error;pos.pm;pos.eq.ra
pmdec_error Err. PM(Dec) Standard error of pmdec mas/yr stat.error;pos.pm;pos.eq.dec
parallax Parallax Absolute barycentric stellar parallax of the source at the reference epoch ref_epoch mas pos.parallax
parallax_error Parallax_error Standard error of parallax mas stat.error;pos.parallax
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. mag phot.mag;em.opt;stat.mean
phot_g_mean_flux Flux_G G-band mean flux as electrons per second. s**-1 phot.flux;em.opt;stat.mean
phot_g_mean_flux_error Err. Flux(G) Error on phot_g_mean_flux s**-1 stat.error;phot.flux;em.opt;stat.mean
phot_g_n_obs #Obs G Number of observations contributing to G photometry N/A meta.number
phot_variable_flag Var? Photometric variability flag [Note var] N/A meta.code;src.var
ref_epoch Epoch Reference epoch to which the astrometic source parameters are referred, expressed as a Julian Year in TCB. yr meta.ref;time.epoch
astrometric_delta_q δq(HIP) Hipparcos/Gaia data discrepancy (Hipparcos subset of TGAS only) [Note dq] N/A stat.value
astrometric_excess_noise Ex. Noise Excess noise of the source [Note en] mas stat.value
astrometric_excess_noise_sig Sig. Noise Significance of excess noise [Note en] N/A stat.value
astrometric_n_obs_ac #Obs AC Total number of observations AC [Note n] N/A meta.number
astrometric_n_obs_al #Obs AL Total number of observations AL [Note n] N/A meta.number
astrometric_n_bad_obs_ac #Bad AC Number of bad observations AC [Note nb] N/A meta.number
astrometric_n_bad_obs_al #Bad AL Number of bad observations AL [Note nb] N/A meta.number
astrometric_n_good_obs_ac #Good AC Number of good observations AC [Note ng] N/A meta.number
astrometric_n_good_obs_al #Good AL Number of good observations AL [Note ng] N/A meta.number
astrometric_primary_flag Primary? Only primary sources (for which this flag is True) contribute to the estimation of attitude, calibration, and global parameters. The estimation of source parameters is not affected by primariness. N/A meta.code
matched_observations Matched_observations The number of observations (detection transits) that have been matched to a given source during the last internal crossmatch revision. N/A meta.number
astrometric_priors_used Prior Type of prior used in in the astrometric solution [Note pri] N/A N/A
astrometric_relegation_factor Releg. fct. Relegation factor of the source calculated as per Eq. (118) in 2012A&A...538A..78L used for the primary selection process. N/A arith.factor
astrometric_weight_ac Weight AC Mean astrometric weight of the source [Note maw] mas**-2 stat.weight;stat.mean
astrometric_weight_al Weight AL Mean astrometric weight of the source [Note maw] mas**-2 stat.weight;stat.mean
duplicated_source Dup? During data processing, this source happened to been duplicated and one source only has been kept. [Note dup] N/A N/A
ra_dec_corr RA-Dec-Corr Correlation between right ascension and declination [Note cr] N/A stat.correlation
ra_pmra_corr RA-PM(RA) Corr. Correlation between right ascension and proper motion in right ascension [Note cr] N/A stat.correlation
ra_pmdec_corr RA-PM(Dec) Corr. Correlation between right ascension and proper motion in declination [Note cr] N/A stat.correlation
dec_pmra_corr Dec-PM(RA) Corr. Correlation between declination and proper motion in right ascension [Note cr] N/A stat.correlation
dec_pmdec_corr Dec-PM(Dec) Corr. Correlation between declination and proper motion in declination [Note cr] N/A stat.correlation
pmra_pmdec_corr PM(RA)-RM(Dec)-RA Correlation between proper motion in right ascension and proper motion in declination [Note cr] N/A stat.correlation
ra_parallax_corr RA-π Corr. Correlation between right ascension and parallax [Note cr] N/A stat.correlation
dec_parallax_corr RA-Dec Corr. Correlation between declination and parallax [Note cr] N/A stat.correlation
parallax_pmra_corr π-PM(RA) Corr. Correlation between parallax and proper motion in right ascension [Note cr] N/A stat.correlation
parallax_pmdec_corr π-PM(Dec) Corr. Correlation between parallax and proper motion in declination [Note cr] N/A stat.correlation
scan_direction_mean_k1 Scan dir. k1 Mean position angle of scan directions across the source [Note sk] deg N/A
scan_direction_strength_k1 Scan conc. k1 Degree of concentration of scan directions across the source [Note sk] N/A N/A
scan_direction_mean_k2 Scan dir. k2 Mean position angle of scan directions across the source [Note sk] deg N/A
scan_direction_strength_k2 Scan conc. k2 Degree of concentration of scan directions across the source [Note sk] N/A N/A
scan_direction_mean_k3 Scan dir. k3 Mean position angle of scan directions across the source [Note sk] deg N/A
scan_direction_strength_k3 Scan conc. k3 Degree of concentration of scan directions across the source [Note sk] N/A N/A
scan_direction_mean_k4 Scan dir. k4 Mean position angle of scan directions across the source [Note sk] deg N/A
scan_direction_strength_k4 Scan conc. k4 Degree of concentration of scan directions across the source [Note sk] N/A N/A
random_index Random Random index that can be used to deterministically select subsets N/A meta.code
hip Hip# Hipparcos identifier N/A N/A
tycho2_id TYC2 # Tycho 2 identifier N/A N/A

Columns that are parts of indices are marked like this.

Other

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Notes

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