{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.673","julian_year":2026.673,"time":"2026-09-03T23:04:32.459Z","years_from_j2000":26.673,"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-4748","name":"NGC 4748","class":"spiral_galaxy_s","category":"galaxy","object_type":"Spiral galaxy S?","mag":14.03,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":210220155.31657088,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":193.05191666666667,"dec_deg":-13.414722222222222,"epoch_ra_deg":193.403658,"epoch_dec_deg":-13.56078,"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":"Corvus","discovered":"1786","featured":false,"url":"https://spacecatalog.org/object/ngc-4748","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.27,"h_mag":10.2,"j_mag":10.9,"k_mag":9.85,"v_mag":14.03,"redshift":0.013753,"hubble_type":"S?","wikidata_id":"Q1113956","redshift_cmb":0.014881470325636359,"discovered_by":"William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[16478791.335821709,16478791.335821709]},"major_axis_arcmin":1.27,"minor_axis_arcmin":0.82,"position_angle_deg":66,"surface_brightness":23.27,"radial_velocity_km_s":4095},"designations":[{"catalog":"2MASX","designation":"2MASX J12521245-1324528"},{"catalog":"IRAS","designation":"IRAS 1249-131P11"},{"catalog":"IRAS","designation":"IRAS 12495-1308"},{"catalog":"IRAS","designation":"IRAS F12495-1308"},{"catalog":"LEDA","designation":"LEDA 43643"},{"catalog":"MCG","designation":"MCG -02-33-034"},{"catalog":"NGC","designation":"NGC 4748"},{"catalog":"PGC","designation":"PGC 43643"}],"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."}