{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.683","julian_year":2026.683,"time":"2026-09-07T14:43:47.695Z","years_from_j2000":26.683,"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-5647","name":"NGC 5647","class":"intermediate_spiral_galaxy_saba","category":"galaxy","object_type":"Intermediate spiral galaxy SABa","mag":15.41,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":363292621.5582956,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":217.65041666666667,"dec_deg":11.876694444444444,"epoch_ra_deg":217.975871,"epoch_dec_deg":11.757111,"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":"Boötes","discovered":"1880","featured":false,"url":"https://spacecatalog.org/object/ngc-5647","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":15.41,"h_mag":11.25,"j_mag":11.87,"k_mag":10.99,"redshift":0.024753,"hubble_type":"SABa","wikidata_id":"Q1121721","redshift_cmb":0.02551565463409844,"discovered_by":"Édouard Stephan","ngc_type_code":"G","uncertainties":{"distance_ly":[20425478.696784355,20425478.696784355]},"major_axis_arcmin":1.02,"minor_axis_arcmin":0.24,"position_angle_deg":180,"surface_brightness":23.66,"radial_velocity_km_s":7329},"designations":[{"catalog":"2MASX","designation":"2MASX J14303611+1152360"},{"catalog":"LEDA","designation":"LEDA 51843"},{"catalog":"MCG","designation":"MCG +02-37-017"},{"catalog":"NGC","designation":"NGC 5647"},{"catalog":"PGC","designation":"PGC 51843"},{"catalog":"SDSS","designation":"SDSS J143036.09+115236.0"},{"catalog":"UGC","designation":"UGC 9329"}],"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."}