{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.672","julian_year":2026.672,"time":"2026-09-03T13:22:27.767Z","years_from_j2000":26.672,"frame":"date","applied":"Proper motion, then precession and nutation. The catalogued J2000 position is carried along the great circle the object's own published motion puts it on, at a constant velocity, and the result is referred to the true equator and equinox of this instant. Those are separate things: the motion moves the object, and the rotation turns the grid under it by about fifty arcseconds a year, with nutation adding up to another seventeen.","excluded":"Parallax, the radial-velocity perspective term, aberration and refraction; each is below the accuracy of the catalogued positions themselves. An object with no published proper motion comes back where the catalogue has it rather than at a fabricated zero, and says so with a null pm_ra_mas_yr. A body with no fixed position is not propagated at all — its place comes from an ephemeris, which is what /api/v1/visible answers with."},"slug":"pgc-21783","name":"PGC 21783","class":"barred_spiral_galaxy_sbbcr","category":"galaxy","object_type":"Barred spiral galaxy SBbcr","mag":15.239,"mag_band":"B","abs_mag":-18.876887194217193,"abs_mag_band":"B","distance_ly":217071753.28362364,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":116.75708,"dec_deg":16.505293,"epoch_ra_deg":117.140843,"epoch_dec_deg":16.43959,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Gemini","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/pgc-21783","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":15.239,"h_mag":13.871,"j_mag":14.566,"k_mag":13.814,"redshift":0.0163,"hubble_type":"SBbcr","redshift_cmb":0.0153609952980419,"uncertainties":{"distance_ly":[11805972.575662643,11808653.54973295],"stellar_mass_solar":[653918993.2469671,653918993.2469671]},"major_axis_arcmin":0.544797,"minor_axis_arcmin":0.511292,"morphology_source":"SIMBAD (2010AJ....139.2525H, quality D)","position_angle_deg":14,"stellar_mass_solar":1494671984.5644958},"designations":[{"catalog":"2MASX","designation":"2MASX 07470169+1630190"},{"catalog":"PGC","designation":"PGC 21783"},{"catalog":"WISExSCOS","designation":"WISExSCOS J074701.74+163018.8"}],"source":{"id":"glade_plus","name":"GLADE+ (Galaxy List for the Advanced Detector Era)","url":"https://cdsarc.cds.unistra.fr/viz-bin/cat/VII/291","license":"VizieR terms; cite Dalya+ 2022 (2022MNRAS.514.1403D)"},"updated_at":"2026-09-02T19:50:56.720Z","attribution":"Data from SpaceCatalog.org. Individual records carry their source and license in `source`; attribution is required for CC-BY and CC-BY-SA rows."}