{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.671","julian_year":2026.671,"time":"2026-09-03T06:09:08.804Z","years_from_j2000":26.671,"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-3384","name":"NGC 3384","class":"elliptical_galaxy_e_s0","category":"galaxy","object_type":"Elliptical galaxy E-S0","mag":9.96,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":50436500.76845203,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":162.070375,"dec_deg":12.629277777777778,"epoch_ra_deg":162.425055,"epoch_dec_deg":12.487611,"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":"Leo","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ngc-3384","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":10.89,"h_mag":7,"j_mag":7.67,"k_mag":6.75,"v_mag":9.96,"redshift":0.002442,"hubble_type":"E-S0","redshift_cmb":0.0036008547960164616,"ngc_type_code":"G","uncertainties":{"distance_ly":[14163016.978933027,14163016.978933027]},"major_axis_arcmin":5.24,"minor_axis_arcmin":2.37,"position_angle_deg":53,"surface_brightness":23.17,"radial_velocity_km_s":731},"designations":[{"catalog":"2MASX","designation":"2MASX J10481689+1237454"},{"catalog":"MCG","designation":"MCG +02-28-012"},{"catalog":"NGC","designation":"NGC 3371"},{"catalog":"NGC","designation":"NGC 3384"},{"catalog":"PGC","designation":"PGC 32292"},{"catalog":"SDSS","designation":"SDSS J104816.88+123745.3"},{"catalog":"UGC","designation":"UGC 5911"}],"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."}