{"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":"2026-09-04T15:20:39.627Z","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-5147","name":"NGC 5147","class":"spiral_galaxy_sd","category":"galaxy","object_type":"Spiral galaxy Sd","mag":12.13,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":65549613.496349424,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":201.58220833333334,"dec_deg":2.100861111111111,"epoch_ra_deg":201.924424,"epoch_dec_deg":1.961146,"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":"1784","featured":false,"url":"https://spacecatalog.org/object/ngc-5147","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":12.28,"h_mag":9.91,"j_mag":10.57,"k_mag":9.73,"v_mag":12.13,"redshift":0.003659,"hubble_type":"Sd","wikidata_id":"Q1117292","redshift_cmb":0.004676021344682368,"discovered_by":"William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[14274338.510753298,14274338.510753298]},"major_axis_arcmin":1.47,"minor_axis_arcmin":1.36,"position_angle_deg":160,"surface_brightness":21.78,"radial_velocity_km_s":1095},"designations":[{"catalog":"2MASX","designation":"2MASX J13261970+0206027"},{"catalog":"IRAS","designation":"IRAS 13237+0221"},{"catalog":"LEDA","designation":"LEDA 47027"},{"catalog":"MCG","designation":"MCG +00-34-033"},{"catalog":"NGC","designation":"NGC 5147"},{"catalog":"PGC","designation":"PGC 47027"},{"catalog":"SDSS","designation":"SDSS J132619.73+020603.0"},{"catalog":"UGC","designation":"UGC 8443"}],"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."}