{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.654","julian_year":2026.654,"time":"2026-08-27T20:43:29.706Z","years_from_j2000":26.654,"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":"ngc-4340","name":"NGC 4340","class":"lenticular_galaxy_s0_a","category":"galaxy","object_type":"Lenticular galaxy S0-a","mag":11.15,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":58082437.22163106,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":185.89704166666664,"dec_deg":16.72236111111111,"epoch_ra_deg":186.236952,"epoch_dec_deg":16.573509,"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":"Coma Berenices","discovered":"1784","featured":false,"url":"https://spacecatalog.org/object/ngc-4340","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":12.08,"h_mag":8.53,"j_mag":9.22,"k_mag":8.32,"v_mag":11.15,"redshift":0.003069,"hubble_type":"S0-a","wikidata_id":"Q1110807","redshift_cmb":0.00414501492025332,"discovered_by":"William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[14216188.732420128,14216188.732420128]},"major_axis_arcmin":2.82,"minor_axis_arcmin":1.79,"wikipedia_article":"NGC 4340","position_angle_deg":87,"surface_brightness":23.03,"radial_velocity_km_s":919},"designations":[{"catalog":"2MASX","designation":"2MASX J12233531+1643199"},{"catalog":"LEDA","designation":"LEDA 40245"},{"catalog":"MCG","designation":"MCG +03-32-021"},{"catalog":"NGC","designation":"NGC 4340"},{"catalog":"PGC","designation":"PGC 40245"},{"catalog":"SDSS","designation":"SDSS J122335.28+164320.4"},{"catalog":"UGC","designation":"UGC 7467"}],"source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-27T19:16:43.430Z","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."}