{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.665","julian_year":2026.665,"time":"2026-08-31T23:27:37.086Z","years_from_j2000":26.665,"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-6955","name":"NGC 6955","class":"intermediate_spiral_galaxy_sabb","category":"galaxy","object_type":"Intermediate spiral galaxy SABb","mag":15.27,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":376325113.08219546,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":311.0749166666667,"dec_deg":2.5948333333333333,"epoch_ra_deg":311.413632,"epoch_dec_deg":2.691622,"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":"Delphinus","discovered":"1863","featured":false,"url":"https://spacecatalog.org/object/ngc-6955","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":15.27,"h_mag":11.06,"j_mag":11.88,"k_mag":10.8,"redshift":0.027426,"hubble_type":"SABb","wikidata_id":"Q1148761","redshift_cmb":0.026413559054484725,"discovered_by":"Albert Marth","ngc_type_code":"G","uncertainties":{"distance_ly":[20811336.3765999,20811336.3765999]},"major_axis_arcmin":1.27,"minor_axis_arcmin":0.98,"position_angle_deg":115,"surface_brightness":24.16,"radial_velocity_km_s":8109},"designations":[{"catalog":"2MASX","designation":"2MASX J20441797+0235414"},{"catalog":"IRAS","designation":"IRAS F20417+0224"},{"catalog":"LEDA","designation":"LEDA 65287"},{"catalog":"NGC","designation":"NGC 6955"},{"catalog":"PGC","designation":"PGC 65287"},{"catalog":"UGC","designation":"UGC 11621"}],"source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-30T09:56:50.739Z","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."}