{"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":"2026-09-08T13:35:31.754Z","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-1820","name":"UGC 1820","class":"spiral_galaxy_sc","category":"galaxy","object_type":"Spiral galaxy Sc","mag":13.99,"mag_band":"B","abs_mag":-19.442285163790295,"abs_mag_band":"B","distance_ly":158446594.00814322,"distance_method":"luminosity distance from a photometric redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":35.443562,"dec_deg":33.020821,"epoch_ra_deg":35.843425,"epoch_dec_deg":33.143741,"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":"Triangulum","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ugc-1820","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":13.99,"h_mag":12.301,"j_mag":12.958,"k_mag":11.887,"redshift":0.013069986535,"hubble_type":"Sc","redshift_cmb":0.0112469875836418,"uncertainties":{"distance_ly":[38737221.63748867,38874965.5070863],"stellar_mass_solar":[934194149.9144609,934194149.9144609]},"major_axis_arcmin":0.86,"minor_axis_arcmin":0.172,"morphology_source":"SIMBAD (2003A&A...412...45P, quality E)","position_angle_deg":125,"stellar_mass_solar":1868388299.8289218},"designations":[{"catalog":"2MASX","designation":"2MASX 02214645+3301149"},{"catalog":"PGC","designation":"PGC 8984"},{"catalog":"WISExSCOS","designation":"WISExSCOS J022146.36+330115.2"}],"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."}