{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.683","julian_year":2026.683,"time":"2026-09-07T09:14:49.980Z","years_from_j2000":26.683,"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-3816171","name":"PGC 3816171","class":"galaxy","category":"galaxy","object_type":"Galaxy","mag":15.85,"mag_band":"B","abs_mag":-17.58787490055461,"abs_mag_band":"B","distance_ly":158854987.7159272,"distance_method":"luminosity distance from a photometric redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":208.999,"dec_deg":-34.05967,"epoch_ra_deg":209.391335,"epoch_dec_deg":-34.191367,"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":"Centaurus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/pgc-3816171","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":15.85,"h_mag":13.271,"j_mag":13.918,"k_mag":13.091,"redshift":0.0122973961487,"redshift_cmb":0.0112757331845625,"uncertainties":{"distance_ly":[35771352.69265505,35895604.00632638],"stellar_mass_solar":[467097003.7349958,467097003.7349958]},"stellar_mass_solar":653935805.2289943},"designations":[{"catalog":"2MASX","designation":"2MASX 13555968-3403351"},{"catalog":"Other","designation":"2MASXJ13555968-3403351"},{"catalog":"PGC","designation":"PGC 3816171"}],"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."}