{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.671","julian_year":2026.671,"time":"2026-09-03T02:52:56.293Z","years_from_j2000":26.671,"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-38640","name":"PGC 38640","class":"spiral_galaxy_sc","category":"galaxy","object_type":"Spiral galaxy Sc","mag":15.633,"mag_band":"B","abs_mag":-19.07617388949819,"abs_mag_band":"B","distance_ly":285272989.37233734,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":182.373932,"dec_deg":39.815762,"epoch_ra_deg":182.714359,"epoch_dec_deg":39.666324,"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":"Canes Venatici","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/pgc-38640","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":15.633,"h_mag":12.755,"j_mag":13.461,"k_mag":12.442,"redshift":0.02142,"hubble_type":"Sc","redshift_cmb":0.0201159833506788,"uncertainties":{"distance_ly":[15542544.218099128,15547172.69591181],"stellar_mass_solar":[2802426134.4559793,2802426134.4559793]},"major_axis_arcmin":0.672757,"minor_axis_arcmin":0.279732,"morphology_source":"SIMBAD (2003A&A...412...45P, quality E)","position_angle_deg":160,"stellar_mass_solar":5604852268.911959},"designations":[{"catalog":"2MASX","designation":"2MASX 12092974+3948567"},{"catalog":"PGC","designation":"PGC 38640"},{"catalog":"WISExSCOS","designation":"WISExSCOS J120929.70+394856.8"}],"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."}