{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.666","julian_year":2026.666,"time":"2026-09-01T04:17:00.277Z","years_from_j2000":26.666,"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-13684","name":"PGC 13684","class":"galaxy","category":"galaxy","object_type":"Galaxy","mag":14.625,"mag_band":"B","abs_mag":-15.88023097985284,"abs_mag_band":"B","distance_ly":41159687.7279783,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":55.898006,"dec_deg":-16.014431,"epoch_ra_deg":56.206869,"epoch_dec_deg":-15.929045,"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":"Eridanus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/pgc-13684","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.625,"h_mag":12.759,"j_mag":13.385,"k_mag":12.384,"redshift":0.00406,"redshift_cmb":0.0029400233970779,"uncertainties":{"distance_ly":[5050006.966475528,5050103.38279847],"stellar_mass_solar":[18684860.66977067,18684860.66977067]},"stellar_mass_solar":37369721.33954134},"designations":[{"catalog":"2MASX","designation":"2MASX 03433552-1600519"},{"catalog":"PGC","designation":"PGC 13684"},{"catalog":"WISExSCOS","designation":"WISExSCOS J034335.50-160051"}],"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."}