{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.664","julian_year":2026.664,"time":"2026-08-31T09:06:46.165Z","years_from_j2000":26.664,"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-2139","name":"NGC 2139","class":"spiral_galaxy_sc","category":"galaxy","object_type":"Spiral galaxy Sc","mag":11.66,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":90347541.42633453,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":90.28254166666666,"dec_deg":-23.67263888888889,"epoch_ra_deg":90.560984,"epoch_dec_deg":-23.671414,"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":"Lepus","discovered":"1784","featured":false,"url":"https://spacecatalog.org/object/ngc-2139","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":11.98,"h_mag":9.66,"j_mag":10.23,"k_mag":9.34,"v_mag":11.66,"redshift":0.006135,"hubble_type":"Sc","wikidata_id":"Q1047119","redshift_cmb":0.006436411469439074,"discovered_by":"William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[14510554.865429625,14510554.865429625]},"major_axis_arcmin":2.94,"minor_axis_arcmin":2.16,"wikipedia_article":"NGC 2139","position_angle_deg":124,"surface_brightness":22.8,"radial_velocity_km_s":1834},"designations":[{"catalog":"2MASX","designation":"2MASX J06010796-2340203"},{"catalog":"ESO","designation":"ESO 488-054"},{"catalog":"ESO","designation":"ESO 488-54"},{"catalog":"ESO-LV","designation":"ESO-LV 488-0540"},{"catalog":"IC","designation":"IC 2154"},{"catalog":"IRAS","designation":"IRAS 05590-2340"},{"catalog":"IRAS","designation":"IRAS F05590-2340"},{"catalog":"LEDA","designation":"LEDA 18258"},{"catalog":"MCG","designation":"MCG -04-15-005"},{"catalog":"NGC","designation":"NGC 2139"},{"catalog":"PGC","designation":"PGC 18258"}],"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."}