{"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":"2026-09-02T23:56:44.341Z","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-6399","name":"NGC 6399","class":"lenticular_galaxy_s0_a","category":"galaxy","object_type":"Lenticular galaxy S0-a","mag":14.6,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":512390987.01481724,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":262.9595833333333,"dec_deg":59.61552777777778,"epoch_ra_deg":263.051148,"epoch_dec_deg":59.595041,"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":"Draco","discovered":"1885","featured":false,"url":"https://spacecatalog.org/object/ngc-6399","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.6,"h_mag":10.53,"j_mag":11.24,"k_mag":10.34,"redshift":0.03591,"hubble_type":"S0-a","wikidata_id":"Q1145551","redshift_cmb":0.03572060211817707,"discovered_by":"Lewis A. Swift","ngc_type_code":"G","uncertainties":{"distance_ly":[25142410.319498237,25142410.319498237]},"major_axis_arcmin":1.21,"minor_axis_arcmin":0.58,"position_angle_deg":13,"surface_brightness":23.7,"radial_velocity_km_s":10572},"designations":[{"catalog":"2MASX","designation":"2MASX J17315029+5936555"},{"catalog":"LEDA","designation":"LEDA 60442"},{"catalog":"MCG","designation":"MCG +10-25-059"},{"catalog":"NGC","designation":"NGC 6399"},{"catalog":"PGC","designation":"PGC 60442"},{"catalog":"SDSS","designation":"SDSS J173150.28+593656.0"},{"catalog":"SDSS","designation":"SDSS J173150.29+593655.9"},{"catalog":"SDSS","designation":"SDSS J173150.29+593656.0"},{"catalog":"SDSS","designation":"SDSS J173150.30+593655.7"},{"catalog":"SDSS","designation":"SDSS J173150.30+593655.8"},{"catalog":"SDSS","designation":"SDSS J173150.30+593655.9"},{"catalog":"UGC","designation":"UGC 10896"}],"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."}