{"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":"2026-09-01T03:24:25.869Z","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-16636","name":"PGC 16636","class":"spiral_galaxy","category":"galaxy","object_type":"Spiral galaxy","mag":12.75,"mag_band":"B","abs_mag":-20.806355485311613,"abs_mag_band":"B","distance_ly":167763304.60043734,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":75.822365,"dec_deg":-2.936501,"epoch_ra_deg":76.158981,"epoch_dec_deg":-2.89807,"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":"Orion","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/pgc-16636","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":12.75,"h_mag":10.368,"j_mag":11.239,"k_mag":9.983,"redshift":0.0135968767984,"hubble_type":"3","redshift_cmb":0.0119024582661196,"uncertainties":{"distance_ly":[12322279.43995367,12323768.635727044],"stellar_mass_solar":[6539332226.23501,6539332226.23501]},"major_axis_arcmin":1.133,"minor_axis_arcmin":0.385,"morphology_source":"SIMBAD (2005ApJS..160..149S, quality D)","position_angle_deg":95,"stellar_mass_solar":14947045088.537167},"designations":[{"catalog":"2MASX","designation":"2MASX 05031736-0256114"},{"catalog":"PGC","designation":"PGC 16636"},{"catalog":"WISExSCOS","designation":"WISExSCOS J050317.33-025611.9"}],"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."}