{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.686","julian_year":2026.686,"time":"2026-09-08T16:21:12.539Z","years_from_j2000":26.686,"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-3866","name":"UGC 3866","class":"spiral_galaxy_sbc","category":"galaxy","object_type":"Spiral galaxy Sbc","mag":14.831,"mag_band":"B","abs_mag":-20.446425743378608,"abs_mag_band":"B","distance_ly":370604786.3201726,"distance_method":"luminosity distance from a photometric redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":112.154716,"dec_deg":30.929985,"epoch_ra_deg":112.582349,"epoch_dec_deg":30.875195,"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":"Gemini","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ugc-3866","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.831,"h_mag":12.431,"j_mag":13.215,"k_mag":12.19,"redshift":0.026298,"hubble_type":"Sbc","redshift_cmb":0.0260195852680209,"uncertainties":{"distance_ly":[77734248.1014773,78295088.78898469],"stellar_mass_solar":[6538751641.184429,6538751641.184429]},"major_axis_arcmin":0.926517,"minor_axis_arcmin":0.312421,"morphology_source":"SIMBAD (2003A&A...412...45P, quality E)","position_angle_deg":178,"stellar_mass_solar":10275181150.432674},"designations":[{"catalog":"2MASX","designation":"2MASX 07283713+3055479"},{"catalog":"PGC","designation":"PGC 21086"},{"catalog":"WISExSCOS","designation":"WISExSCOS J072837.13+305547"}],"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."}