{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.665","julian_year":2026.665,"time":"2026-08-31T20:10:36.069Z","years_from_j2000":26.665,"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-4378","name":"IC 4378","class":"lenticular_galaxy_s0","category":"galaxy","object_type":"Lenticular galaxy S0","mag":14.55,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":212194564.97897577,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":213.039875,"dec_deg":-34.26533333333333,"epoch_ra_deg":213.438465,"epoch_dec_deg":-34.39161,"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":"Centaurus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ic-4378","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.55,"h_mag":10.54,"j_mag":11.22,"k_mag":10.18,"redshift":0.01421,"hubble_type":"S0","wikidata_id":"Q2592930","redshift_cmb":0.015019688589211544,"ngc_type_code":"G","uncertainties":{"distance_ly":[16521058.512345405,16521058.512345405]},"major_axis_arcmin":1.54,"minor_axis_arcmin":0.61,"position_angle_deg":158,"surface_brightness":24.17,"radial_velocity_km_s":4230},"designations":[{"catalog":"2MASX","designation":"2MASX J14120952-3415550"},{"catalog":"ESO","designation":"ESO 384-064"},{"catalog":"ESO","designation":"ESO 384-64"},{"catalog":"ESO-LV","designation":"ESO-LV 384-0640"},{"catalog":"IC","designation":"IC 4378"},{"catalog":"LEDA","designation":"LEDA 50711"},{"catalog":"MCG","designation":"MCG -06-31-027"},{"catalog":"PGC","designation":"PGC 50711"}],"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."}