{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.666","julian_year":2026.666,"time":"2026-09-01T04:53:02.964Z","years_from_j2000":26.666,"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-551","name":"IC 551","class":"spiral_galaxy_sbc","category":"galaxy","object_type":"Spiral galaxy Sbc","mag":14.56,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":424533011.74490064,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":145.25045833333334,"dec_deg":6.936083333333333,"epoch_ra_deg":145.604892,"epoch_dec_deg":6.814333,"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":"Leo","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ic-551","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.56,"h_mag":11.23,"j_mag":11.88,"k_mag":10.86,"redshift":0.02859,"hubble_type":"Sbc","wikidata_id":"Q3712504","redshift_cmb":0.029725022044725158,"ngc_type_code":"G","uncertainties":{"distance_ly":[22288062.6992799,22288062.6992799]},"major_axis_arcmin":0.81,"minor_axis_arcmin":0.53,"position_angle_deg":155,"surface_brightness":22.63,"radial_velocity_km_s":8449},"designations":[{"catalog":"2MASX","designation":"2MASX J09410011+0656098"},{"catalog":"IC","designation":"IC 551"},{"catalog":"IRAS","designation":"IRAS F09383+0709"},{"catalog":"LEDA","designation":"LEDA 27645"},{"catalog":"MCG","designation":"MCG +01-25-012"},{"catalog":"PGC","designation":"PGC 27645"},{"catalog":"SDSS","designation":"SDSS J094100.10+065609.9"},{"catalog":"SDSS","designation":"SDSS J094100.11+065609.9"},{"catalog":"UGC","designation":"UGC 5168"}],"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."}