{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.663","julian_year":2026.663,"time":"2026-08-31T03:54:57.873Z","years_from_j2000":26.663,"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":"ic-4239","name":"IC 4239","class":"lenticular_galaxy_s0_a","category":"galaxy","object_type":"Lenticular galaxy S0-a","mag":15.19,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":713363677.5323077,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":201.10595833333332,"dec_deg":30.95927777777778,"epoch_ra_deg":201.418797,"epoch_dec_deg":30.819154,"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":"Canes Venatici","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ic-4239","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":15.19,"h_mag":11.69,"j_mag":12.3,"k_mag":11.42,"redshift":0.04841,"hubble_type":"S0-a","wikidata_id":"Q3683531","redshift_cmb":0.049251146315514305,"ngc_type_code":"G","uncertainties":{"distance_ly":[32186587.17554355,32186587.17554355]},"major_axis_arcmin":0.88,"minor_axis_arcmin":0.63,"position_angle_deg":132,"surface_brightness":23.59,"radial_velocity_km_s":14162},"designations":[{"catalog":"2MASX","designation":"2MASX J13242547+3057336"},{"catalog":"IC","designation":"IC 4239"},{"catalog":"LEDA","designation":"LEDA 46872"},{"catalog":"MCG","designation":"MCG +05-32-015"},{"catalog":"PGC","designation":"PGC 46872"},{"catalog":"SDSS","designation":"SDSS J132425.42+305733.4"},{"catalog":"SDSS","designation":"SDSS J132425.43+305733.4"}],"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."}