{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.685","julian_year":2026.685,"time":"2026-09-08T05:21:53.804Z","years_from_j2000":26.685,"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":"ugc-4393","name":"UGC 4393","class":"intermediate_spiral_galaxy_sabb","category":"galaxy","object_type":"Intermediate spiral galaxy SABb","mag":12.7,"mag_band":"B","abs_mag":-18.290383691981727,"abs_mag_band":"B","distance_ly":51463890.41263799,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":126.51815,"dec_deg":45.967457,"epoch_ra_deg":126.987647,"epoch_dec_deg":45.879797,"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/ugc-4393","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":12.7,"h_mag":11.802,"j_mag":12.366,"k_mag":11.654,"redshift":0.00314202157101,"hubble_type":"SABb","redshift_cmb":0.003674,"uncertainties":{"distance_ly":[2436463.910850094,2436556.5629884666],"stellar_mass_solar":[89488722.42028405,89488722.42028405]},"major_axis_arcmin":2.2968,"minor_axis_arcmin":0.914356,"morphology_source":"SIMBAD (2013MNRAS.434..336H, quality C)","position_angle_deg":54,"stellar_mass_solar":204545651.24636352},"designations":[{"catalog":"2MASX","designation":"2MASX 08260435+4558028"},{"catalog":"PGC","designation":"PGC 23660"}],"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."}