{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.665","julian_year":2026.665,"time":"2026-08-31T23:08:08.811Z","years_from_j2000":26.665,"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-21777","name":"PGC 21777","class":"spiral_galaxy_sd","category":"galaxy","object_type":"Spiral galaxy Sd","mag":14.8,"mag_band":"B","abs_mag":-19.801524370234805,"abs_mag_band":"B","distance_ly":271475567.24624866,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":116.753746,"dec_deg":51.435257,"epoch_ra_deg":117.265856,"epoch_dec_deg":51.369449,"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":"Lynx","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/pgc-21777","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.8,"h_mag":12.322,"j_mag":13.093,"k_mag":12.02,"redshift":0.01987,"hubble_type":"Sd","redshift_cmb":0.0191566804906768,"uncertainties":{"distance_ly":[14890368.829414548,14894224.179816784],"stellar_mass_solar":[2802443001.170377,2802443001.170377]},"major_axis_arcmin":0.985333,"minor_axis_arcmin":0.264956,"morphology_source":"SIMBAD (2010AJ....139.2525H, quality D)","position_angle_deg":71,"stellar_mass_solar":5604886002.340754},"designations":[{"catalog":"2MASX","designation":"2MASX 07470089+5126069"},{"catalog":"PGC","designation":"PGC 21777"},{"catalog":"WISExSCOS","designation":"WISExSCOS J074701.01+512607.1"}],"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":"2026-08-30T09:56:50.739Z","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."}