{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.668","julian_year":2026.668,"time":"2026-09-02T02:29:36.237Z","years_from_j2000":26.668,"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-451","name":"NGC 451","class":"spiral_galaxy_sc","category":"galaxy","object_type":"Spiral galaxy Sc","mag":14.76,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":218404256.08804727,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":19.051666666666666,"dec_deg":33.06411111111111,"epoch_ra_deg":19.426391,"epoch_dec_deg":33.205993,"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":"Pisces","discovered":"1881","featured":false,"url":"https://spacecatalog.org/object/ngc-451","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.76,"h_mag":11.7,"j_mag":12.3,"k_mag":11.39,"redshift":0.01643,"hubble_type":"Sc","wikidata_id":"Q773058","redshift_cmb":0.015454214416232626,"discovered_by":"Édouard Stephan","ngc_type_code":"G","uncertainties":{"distance_ly":[16655767.763639908,16655767.763639908]},"major_axis_arcmin":0.69,"minor_axis_arcmin":0.53,"wikipedia_article":"NGC 451","position_angle_deg":19,"surface_brightness":22.61,"radial_velocity_km_s":4887},"designations":[{"catalog":"2MASX","designation":"2MASX J01161239+3303507"},{"catalog":"LEDA","designation":"LEDA 4594"},{"catalog":"MCG","designation":"MCG +05-04-011"},{"catalog":"NGC","designation":"NGC 451"},{"catalog":"PGC","designation":"PGC 4594"}],"source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-01T22:58:55.274Z","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."}