{"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":"2026-08-31T12:01:05.606Z","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-902","name":"IC 902","class":"spiral_galaxy_sb","category":"galaxy","object_type":"Spiral galaxy Sb","mag":14.48,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":83001830.72358173,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":204.00508333333332,"dec_deg":49.96083333333333,"epoch_ra_deg":204.278998,"epoch_dec_deg":49.8235,"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":"Ursa Major","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ic-902","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.48,"h_mag":10.6,"j_mag":11.44,"k_mag":10.42,"redshift":0.00539,"hubble_type":"Sb","wikidata_id":"Q3711675","redshift_cmb":0.005915429648973625,"ngc_type_code":"G","uncertainties":{"distance_ly":[14433784.374858746,14433784.374858746]},"major_axis_arcmin":2.18,"minor_axis_arcmin":0.55,"position_angle_deg":162,"surface_brightness":23.98,"radial_velocity_km_s":1612},"designations":[{"catalog":"2MASX","designation":"2MASX J13360121+4957385"},{"catalog":"IC","designation":"IC 902"},{"catalog":"IRAS","designation":"IRAS 13340+5012"},{"catalog":"IRAS","designation":"IRAS F13340+5012"},{"catalog":"LEDA","designation":"LEDA 47985"},{"catalog":"MCG","designation":"MCG +08-25-024"},{"catalog":"PGC","designation":"PGC 47985"},{"catalog":"SDSS","designation":"SDSS J133601.21+495739.0"},{"catalog":"SDSS","designation":"SDSS J133601.22+495739.0"},{"catalog":"UGC","designation":"UGC 8593"}],"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."}