{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.680","julian_year":2026.68,"time":"2026-09-06T06:38:41.893Z","years_from_j2000":26.68,"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-3220","name":"NGC 3220","class":"spiral_galaxy_sb","category":"galaxy","object_type":"Spiral galaxy Sb","mag":13.95,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":63043313.48377633,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":155.9360833333333,"dec_deg":57.02686111111111,"epoch_ra_deg":156.376447,"epoch_dec_deg":56.890998,"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":"Ursa Major","discovered":"1793","featured":false,"url":"https://spacecatalog.org/object/ngc-3220","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":13.91,"h_mag":11.79,"j_mag":12.17,"k_mag":11.6,"v_mag":13.95,"redshift":0.003969,"hubble_type":"Sb","wikidata_id":"Q1103615","redshift_cmb":0.004497840587106783,"discovered_by":"William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[14254140.123324212,14254140.123324212]},"major_axis_arcmin":1.18,"minor_axis_arcmin":0.48,"wikipedia_article":"NGC 3220","position_angle_deg":96,"surface_brightness":22.57,"radial_velocity_km_s":1188},"designations":[{"catalog":"2MASX","designation":"2MASX J10234426+5701375"},{"catalog":"IC","designation":"IC 604"},{"catalog":"LEDA","designation":"LEDA 30462"},{"catalog":"MCG","designation":"MCG +10-15-073"},{"catalog":"NGC","designation":"NGC 3220"},{"catalog":"PGC","designation":"PGC 30462"},{"catalog":"SDSS","designation":"SDSS J102344.65+570136.8"},{"catalog":"SDSS","designation":"SDSS J102344.66+570136.7"},{"catalog":"UGC","designation":"UGC 5614"}],"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."}