{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.677","julian_year":2026.677,"time":"2026-09-05T07:31:08.473Z","years_from_j2000":26.677,"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-4449","name":"NGC 4449","class":"irregular_galaxy_ib","category":"galaxy","object_type":"Irregular galaxy IB","mag":9.64,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":187.04625,"dec_deg":44.09363888888889,"epoch_ra_deg":187.374449,"epoch_dec_deg":43.945004,"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":"Canes Venatici","discovered":"1788","featured":false,"url":"https://spacecatalog.org/object/ngc-4449","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":9.5,"h_mag":7.45,"j_mag":8.1,"k_mag":7.25,"v_mag":9.64,"redshift":0.00068,"hubble_type":"IB","wikidata_id":"Q631918","redshift_cmb":0.001407744019072954,"discovered_by":"William Herschel","ngc_type_code":"G","major_axis_arcmin":4.66,"minor_axis_arcmin":2.71,"wikipedia_article":"NGC 4449","position_angle_deg":51,"surface_brightness":21.1,"radial_velocity_km_s":204},"designations":[{"catalog":"2MASX","designation":"2MASX J12281111+4405368"},{"catalog":"Caldwell","designation":"C 21"},{"catalog":"LEDA","designation":"LEDA 40973"},{"catalog":"MCG","designation":"MCG +07-26-009"},{"catalog":"NGC","designation":"NGC 4449"},{"catalog":"PGC","designation":"PGC 40973"},{"catalog":"SDSS","designation":"SDSS J122811.10+440537.0"},{"catalog":"UGC","designation":"UGC 7592"}],"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."}