{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.675","julian_year":2026.675,"time":"2026-09-04T14:07:16.422Z","years_from_j2000":26.675,"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-4830","name":"NGC 4830","class":"elliptical_galaxy_e_s0","category":"galaxy","object_type":"Elliptical galaxy E-S0","mag":12.09,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":172604392.19486824,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":194.36629166666665,"dec_deg":-19.691277777777778,"epoch_ra_deg":194.72309,"epoch_dec_deg":-19.836574,"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":"Virgo","discovered":"1880","featured":false,"url":"https://spacecatalog.org/object/ngc-4830","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":13.09,"h_mag":9.07,"j_mag":9.8,"k_mag":8.85,"v_mag":12.09,"redshift":0.011148,"hubble_type":"E-S0","wikidata_id":"Q1114673","redshift_cmb":0.012242798629737761,"discovered_by":"Wilhelm Tempel","ngc_type_code":"G","uncertainties":{"distance_ly":[15728713.28138961,15728713.28138961]},"major_axis_arcmin":2.31,"minor_axis_arcmin":1.49,"position_angle_deg":164,"surface_brightness":23.63,"radial_velocity_km_s":3323},"designations":[{"catalog":"2MASX","designation":"2MASX J12572790-1941286"},{"catalog":"ESO","designation":"ESO 575-037"},{"catalog":"ESO","designation":"ESO 575-37"},{"catalog":"ESO-LV","designation":"ESO-LV 575-0370"},{"catalog":"LEDA","designation":"LEDA 44313"},{"catalog":"MCG","designation":"MCG -03-33-024"},{"catalog":"NGC","designation":"NGC 4830"},{"catalog":"PGC","designation":"PGC 44313"}],"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."}