{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.681","julian_year":2026.681,"time":"2026-09-06T18:28:29.477Z","years_from_j2000":26.681,"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-4648","name":"UGC 4648","class":"spiral_galaxy_sa","category":"galaxy","object_type":"Spiral galaxy SA","mag":16.09,"mag_band":"B","abs_mag":-16.33011101395424,"abs_mag_band":"B","distance_ly":99414121.24705882,"distance_method":"luminosity distance from a photometric redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":133.399,"dec_deg":45.33554,"epoch_ra_deg":133.854163,"epoch_dec_deg":45.234008,"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-4648","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":16.09,"redshift":0.00660681330341,"hubble_type":"SA","redshift_cmb":0.0070788816048567,"uncertainties":{"distance_ly":[19279531.97252708,19315254.801099792],"stellar_mass_solar":[65395307.138886444,65395307.138886444]},"major_axis_arcmin":0.600123,"minor_axis_arcmin":0.521147,"morphology_source":"SIMBAD (2019MNRAS.488..590B, quality C)","position_angle_deg":96,"stellar_mass_solar":112106240.80951962},"designations":[{"catalog":"PGC","designation":"PGC 24963"},{"catalog":"WISExSCOS","designation":"WISExSCOS J085335.82+452007.7"}],"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."}