{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.678","julian_year":2026.678,"time":"2026-09-05T14:42:55.519Z","years_from_j2000":26.678,"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-5642","name":"NGC 5642","class":"elliptical_galaxy_e","category":"galaxy","object_type":"Elliptical galaxy E","mag":14.2,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":212880672.25729117,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":217.3062083333333,"dec_deg":30.026444444444444,"epoch_ra_deg":217.598984,"epoch_dec_deg":29.906342,"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":"Boötes","discovered":"1784","featured":false,"url":"https://spacecatalog.org/object/ngc-5642","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.2,"h_mag":9.56,"j_mag":10.23,"k_mag":9.35,"redshift":0.014443,"hubble_type":"E","wikidata_id":"Q1121696","redshift_cmb":0.015067712863164218,"discovered_by":"William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[16535810.579096803,16535810.579096803]},"major_axis_arcmin":1.77,"minor_axis_arcmin":1.13,"wikipedia_article":"NGC 5642","position_angle_deg":126,"surface_brightness":24.12,"radial_velocity_km_s":4299},"designations":[{"catalog":"2MASX","designation":"2MASX J14291348+3001349"},{"catalog":"LEDA","designation":"LEDA 51751"},{"catalog":"MCG","designation":"MCG +05-34-052"},{"catalog":"NGC","designation":"NGC 5642"},{"catalog":"PGC","designation":"PGC 51751"},{"catalog":"SDSS","designation":"SDSS J142913.48+300135.2"},{"catalog":"UGC","designation":"UGC 9301"}],"source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0"},"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."}