{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.654","julian_year":2026.654,"time":"2026-08-27T17:05:41.490Z","years_from_j2000":26.654,"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":"acrab","name":"Acrab","class":"b1v_blue_white_main_sequence_star","category":"star","object_type":"B1V blue-white main-sequence star","mag":2.56,"mag_band":"V","abs_mag":-2.906,"abs_mag_band":"V","distance_ly":404.1589585423466,"distance_method":"parallax","ra_deg":241.35930000000002,"dec_deg":-19.805453,"epoch_ra_deg":241.75021,"epoch_dec_deg":-19.878852,"epoch_moved_arcsec":0.687,"pm_ra_mas_yr":-6.75,"pm_dec_mas_yr":-24.89,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Scorpius","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/acrab","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"16054-1948","companions":[{"measured":2024,"magnitude":10.6,"components":"AB","discoverer_code":"BU  947","separation_arcsec":0.3,"position_angle_deg":226},{"measured":2021,"magnitude":4.52,"components":"AC","discoverer_code":"H 3   7","separation_arcsec":13.7,"position_angle_deg":19},{"measured":2016,"magnitude":7.5,"components":"AD","discoverer_code":"PWL9001","separation_arcsec":519.2,"position_angle_deg":30}],"spectral_type":"B1V","color_index_bv":-0.065,"luminosity_solar":1265.9017493002452,"radial_velocity_km_s":-1,"spectral_type_source":"SIMBAD (1981ApJS...45..437A, quality C)","proper_motion_ra_mas_yr":-6.75,"proper_motion_dec_mas_yr":-24.89},"designations":[{"catalog":"Bayer/Flamsteed","designation":"8 Beta1 Sco"},{"catalog":"Common name","designation":"Acrab"},{"catalog":"HD","designation":"HD 144217"},{"catalog":"HIP","designation":"HIP 78820"},{"catalog":"HR","designation":"HR 5984"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-27T16:03:54.983Z","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."}