{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.672","julian_year":2026.672,"time":"2026-09-03T06:54:07.739Z","years_from_j2000":26.672,"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-2884","name":"NGC 2884","class":"lenticular_galaxy_s0_a","category":"galaxy","object_type":"Lenticular galaxy S0-a","mag":13.61,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":263252721.93904558,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":141.601875,"dec_deg":-11.555583333333335,"epoch_ra_deg":141.926531,"epoch_dec_deg":-11.671578,"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":"Hydra","discovered":"1865","featured":false,"url":"https://spacecatalog.org/object/ngc-2884","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":13.61,"h_mag":9.8,"j_mag":10.5,"k_mag":9.49,"redshift":0.01746,"hubble_type":"S0-a","wikidata_id":"Q1051457","redshift_cmb":0.018584328878636036,"discovered_by":"Heinrich Louis d'Arrest","ngc_type_code":"G","uncertainties":{"distance_ly":[17703297.25772242,17703297.25772242]},"major_axis_arcmin":2.16,"minor_axis_arcmin":0.76,"position_angle_deg":173,"surface_brightness":23.71,"radial_velocity_km_s":5189},"designations":[{"catalog":"2MASX","designation":"2MASX J09262451-1133207"},{"catalog":"IRAS","designation":"IRAS 09239-1120"},{"catalog":"IRAS","designation":"IRAS F09240-1120"},{"catalog":"LEDA","designation":"LEDA 26773"},{"catalog":"MCG","designation":"MCG -02-24-022"},{"catalog":"NGC","designation":"NGC 2884"},{"catalog":"PGC","designation":"PGC 26773"}],"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."}