{"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":"2026-09-08T05:36:36.728Z","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-8231","name":"UGC 8231","class":"spiral_galaxy_sd","category":"galaxy","object_type":"Spiral galaxy Sd","mag":14.104,"mag_band":"B","abs_mag":-19.01827050127679,"abs_mag_band":"B","distance_ly":137366228.80259848,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":197.155258,"dec_deg":54.074451,"epoch_ra_deg":197.441351,"epoch_dec_deg":53.930938,"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":"Ursa Major","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ugc-8231","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.104,"h_mag":12.648,"j_mag":13.347,"k_mag":12.541,"redshift":0.00821,"hubble_type":"Sd","redshift_cmb":0.0097615358898228,"uncertainties":{"distance_ly":[7282251.213426207,7282805.5341305705],"stellar_mass_solar":[280260864.67477465,280260864.67477465]},"major_axis_arcmin":1.31133,"minor_axis_arcmin":0.489388,"morphology_source":"SIMBAD (2021A&A...648A..64K, quality C)","position_angle_deg":75,"stellar_mass_solar":560521729.3495493},"designations":[{"catalog":"2MASX","designation":"2MASX 13083726+5404280"},{"catalog":"PGC","designation":"PGC 45561"},{"catalog":"WISExSCOS","designation":"WISExSCOS J130837.52+540428.2"}],"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."}