{"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":"2026-08-31T18:26:02.471Z","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":"ic-4681","name":"IC 4681","class":"star","category":"star","object_type":"Star","mag":9.1,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":272.0833333333333,"dec_deg":-23.43202777777778,"epoch_ra_deg":272.492062,"epoch_dec_deg":-23.428382,"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":"Sagittarius","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ic-4681","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":9.26,"h_mag":8.93,"j_mag":8.99,"k_mag":8.92,"v_mag":9.1,"wikidata_id":"Q3681735","ngc_type_code":"*"},"designations":[{"catalog":"2MASS","designation":"2MASS J18081997-2325551"},{"catalog":"Cederblad","designation":"Ced 154a"},{"catalog":"HD","designation":"HD 165705"},{"catalog":"IC","designation":"IC 4681"},{"catalog":"IDS","designation":"IDS 18022-2327 AB"},{"catalog":"Lynds","designation":"LBN 007.28-01.59"},{"catalog":"Lynds","designation":"LBN 31"},{"catalog":"SAO","designation":"SAO 186340"},{"catalog":"TYC","designation":"TYC 6842-1272-1"},{"catalog":"WDS","designation":"WDS J18083-2326AB"}],"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."}