{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.654","julian_year":2026.654,"time":"2026-08-27T17:42:14.813Z","years_from_j2000":26.654,"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":"m66","name":"M66","class":"spiral_galaxy_sb","category":"galaxy","object_type":"Spiral galaxy Sb","mag":8.92,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":49041986.336527556,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":170.06233333333336,"dec_deg":12.991527777777778,"epoch_ra_deg":170.412612,"epoch_dec_deg":12.84464,"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":"Leo","discovered":"1780","featured":false,"url":"https://spacecatalog.org/object/m66","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":9.73,"h_mag":6.15,"j_mag":6.84,"k_mag":5.88,"v_mag":8.92,"redshift":0.00234,"hubble_type":"Sb","wikidata_id":"Q13992","redshift_cmb":0.0035015591222131714,"discovered_by":"Charles Messier, Pierre Méchain","ngc_type_code":"G","uncertainties":{"distance_ly":[14154019.93231209,14154019.93231209]},"major_axis_arcmin":10.28,"minor_axis_arcmin":4.61,"wikipedia_article":"Messier 66","position_angle_deg":168,"surface_brightness":22.96,"radial_velocity_km_s":702},"designations":[{"catalog":"2MASX","designation":"2MASX J11201502+1259286"},{"catalog":"IRAS","designation":"IRAS 11176+1315"},{"catalog":"IRAS","designation":"IRAS F11176+1315"},{"catalog":"LEDA","designation":"LEDA 34695"},{"catalog":"MCG","designation":"MCG +02-29-019"},{"catalog":"Messier","designation":"M 66"},{"catalog":"NGC","designation":"NGC 3627"},{"catalog":"PGC","designation":"PGC 34695"},{"catalog":"SDSS","designation":"SDSS J112014.98+125929.4"},{"catalog":"UGC","designation":"UGC 6346"}],"source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-27T16:03:54.983Z","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."}