{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.666","julian_year":2026.666,"time":"2026-09-01T08:03:13.223Z","years_from_j2000":26.666,"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-4246","name":"NGC 4246","class":"spiral_galaxy_sc","category":"galaxy","object_type":"Spiral galaxy Sc","mag":12.72,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":190937387.53030404,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":184.49216666666666,"dec_deg":7.1859166666666665,"epoch_ra_deg":184.834919,"epoch_dec_deg":7.036763,"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":"Virgo","discovered":"1784","featured":false,"url":"https://spacecatalog.org/object/ngc-4246","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":13.41,"h_mag":10.07,"j_mag":10.57,"k_mag":9.95,"v_mag":12.72,"redshift":0.01237,"hubble_type":"Sc","wikidata_id":"Q1110147","redshift_cmb":0.01353010410908273,"discovered_by":"William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[16080832.05397977,16080832.05397977]},"major_axis_arcmin":2.14,"minor_axis_arcmin":1.09,"wikipedia_article":"NGC 4246","position_angle_deg":84,"surface_brightness":23.24,"radial_velocity_km_s":3685},"designations":[{"catalog":"2MASX","designation":"2MASX J12175811+0711091"},{"catalog":"IC","designation":"IC 3113"},{"catalog":"LEDA","designation":"LEDA 39479"},{"catalog":"MCG","designation":"MCG +01-31-041"},{"catalog":"NGC","designation":"NGC 4246"},{"catalog":"PGC","designation":"PGC 39479"},{"catalog":"SDSS","designation":"SDSS J121758.11+071109.2"},{"catalog":"SDSS","designation":"SDSS J121758.12+071109.3"},{"catalog":"UGC","designation":"UGC 7334"}],"source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-30T09:56:50.739Z","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."}