{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.684","julian_year":2026.684,"time":"2026-09-07T20:20:41.432Z","years_from_j2000":26.684,"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-4771","name":"NGC 4771","class":"spiral_galaxy_sc","category":"galaxy","object_type":"Spiral galaxy Sc","mag":12.73,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":69205545.84686342,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":193.33841666666666,"dec_deg":1.2690833333333333,"epoch_ra_deg":193.682004,"epoch_dec_deg":1.123098,"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":"Virgo","discovered":"1786","featured":false,"url":"https://spacecatalog.org/object/ngc-4771","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":12.73,"h_mag":9.28,"j_mag":9.96,"k_mag":9.01,"redshift":0.003829,"hubble_type":"Sc","wikidata_id":"Q1114154","redshift_cmb":0.004935847243576541,"discovered_by":"William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[14305027.829642497,14305027.829642497]},"major_axis_arcmin":3.1,"minor_axis_arcmin":0.98,"position_angle_deg":133,"surface_brightness":22.97,"radial_velocity_km_s":1146},"designations":[{"catalog":"2MASX","designation":"2MASX J12532127+0116090"},{"catalog":"IRAS","designation":"IRAS 12507+0132"},{"catalog":"LEDA","designation":"LEDA 43784"},{"catalog":"MCG","designation":"MCG +00-33-017"},{"catalog":"NGC","designation":"NGC 4771"},{"catalog":"PGC","designation":"PGC 43784"},{"catalog":"SDSS","designation":"SDSS J125321.21+011608.7"},{"catalog":"SDSS","designation":"SDSS J125321.22+011608.7"},{"catalog":"SDSS","designation":"SDSS J125321.22+011608.8"},{"catalog":"SDSS","designation":"SDSS J125321.41+011606.2"},{"catalog":"UGC","designation":"UGC 8020"}],"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."}