{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.664","julian_year":2026.664,"time":"2026-08-31T16:56:39.639Z","years_from_j2000":26.664,"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":"ic-257","name":"IC 257","class":"elliptical_galaxy_e","category":"galaxy","object_type":"Elliptical galaxy E","mag":12.68,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":360315120.34865355,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":42.43933333333333,"dec_deg":46.976194444444445,"epoch_ra_deg":42.890209,"epoch_dec_deg":47.087668,"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":"Perseus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ic-257","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":13.86,"v_mag":12.68,"redshift":0.02592,"hubble_type":"E","wikidata_id":"Q3713865","redshift_cmb":0.025310350932090886,"ngc_type_code":"G","uncertainties":{"distance_ly":[20338196.223690063,20338196.223690063]},"major_axis_arcmin":1.93,"minor_axis_arcmin":1.19,"position_angle_deg":154,"surface_brightness":24.12,"radial_velocity_km_s":7671},"designations":[{"catalog":"MCG","designation":"MCG +08-06-011"}],"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."}