{"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":"2026-09-04T11:18:52.515Z","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-3903","name":"NGC 3903","class":"intermediate_spiral_galaxy_sabc","category":"galaxy","object_type":"Intermediate spiral galaxy SABc","mag":13.53,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":155261011.90389025,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":177.26475,"dec_deg":-37.51711111111111,"epoch_ra_deg":177.601931,"epoch_dec_deg":-37.666369,"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":"Centaurus","discovered":"1835","featured":false,"url":"https://spacecatalog.org/object/ngc-3903","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":13.53,"h_mag":10.44,"j_mag":11.13,"k_mag":10.27,"redshift":0.009963,"hubble_type":"SABc","wikidata_id":"Q1107059","redshift_cmb":0.011022722002360652,"discovered_by":"John Frederick William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[15420759.347879056,15420759.347879056]},"major_axis_arcmin":1.28,"minor_axis_arcmin":1.11,"position_angle_deg":133,"surface_brightness":22.69,"radial_velocity_km_s":2972},"designations":[{"catalog":"2MASX","designation":"2MASX J11490354-3731014"},{"catalog":"ESO","designation":"ESO 378-024"},{"catalog":"ESO","designation":"ESO 378-24"},{"catalog":"ESO-LV","designation":"ESO-LV 378-0240"},{"catalog":"IRAS","designation":"IRAS 11465-3714"},{"catalog":"LEDA","designation":"LEDA 36906"},{"catalog":"MCG","designation":"MCG -06-26-008"},{"catalog":"NGC","designation":"NGC 3903"},{"catalog":"PGC","designation":"PGC 36906"}],"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."}