{"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":"2026-09-05T14:43:35.530Z","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-4038","name":"Antennae Galaxies","class":"barred_spiral_galaxy_sbm","category":"galaxy","object_type":"Barred spiral galaxy SBm","mag":10.2,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":95180725.27051418,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":180.470875,"dec_deg":-18.867611111111113,"epoch_ra_deg":180.814824,"epoch_dec_deg":-19.017165,"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":"Corvus","discovered":"1785","featured":false,"url":"https://spacecatalog.org/object/ngc-4038","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":10.85,"v_mag":10.2,"redshift":0.005593,"hubble_type":"SBm","wikidata_id":"Q2357875","redshift_cmb":0.006778974489809242,"discovered_by":"William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[14564123.78189729,14564123.78189729]},"major_axis_arcmin":5.42,"minor_axis_arcmin":3.78,"position_angle_deg":80,"surface_brightness":22.94,"radial_velocity_km_s":1672},"designations":[{"catalog":"2MASS","designation":"2MASS J12015301-1852034"},{"catalog":"Caldwell","designation":"C 60"},{"catalog":"Common name","designation":"Antennae Galaxies"},{"catalog":"ESO","designation":"ESO 572-047"},{"catalog":"ESO","designation":"ESO 572-47"},{"catalog":"ESO-LV","designation":"ESO-LV 572-0470"},{"catalog":"ESO-LV","designation":"ESO-LV 572-0481"},{"catalog":"LEDA","designation":"LEDA 37967"},{"catalog":"MCG","designation":"MCG -03-31-014"},{"catalog":"NGC","designation":"NGC 4038"},{"catalog":"PGC","designation":"PGC 37967"},{"catalog":"UGCA","designation":"UGCA 264"}],"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."}