{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.673","julian_year":2026.673,"time":"2026-09-03T20:51:46.197Z","years_from_j2000":26.673,"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":"hd-52533","name":"HD 52533","class":"o8_5ivn_blue_subgiant","category":"star","object_type":"O8.5IVn blue subgiant","mag":7.7,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":105.3627,"dec_deg":-3.11758,"epoch_ra_deg":105.698835,"epoch_dec_deg":-3.1554,"epoch_moved_arcsec":0.018,"pm_ra_mas_yr":-0.67,"pm_dec_mas_yr":-0.04,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Monoceros","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-52533","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"07015-0307","companions":[{"measured":2011,"magnitude":11.5,"components":"Aa,Ab","discoverer_code":"FGS  11","separation_arcsec":0.6,"position_angle_deg":268},{"measured":2016,"magnitude":13.2,"components":"AB","discoverer_code":"A   518","separation_arcsec":2.6,"position_angle_deg":188},{"measured":2016,"magnitude":14.29,"components":"AG","discoverer_code":"SNA   4","separation_arcsec":2.9,"position_angle_deg":247},{"measured":2016,"magnitude":14.6,"components":"AE","discoverer_code":"MZA  22","separation_arcsec":11.5,"position_angle_deg":306},{"measured":2017,"magnitude":13.5,"components":"AF","discoverer_code":"MZA  22","separation_arcsec":11.7,"position_angle_deg":195},{"measured":2017,"magnitude":8.77,"components":"AC","discoverer_code":"STF1010","separation_arcsec":22.3,"position_angle_deg":7},{"measured":2017,"magnitude":9.42,"components":"AD","discoverer_code":"ARN  43","separation_arcsec":124.1,"position_angle_deg":251}],"radius_solar":7.475,"spectral_type":"O8.5IVn","color_index_bv":-0.087,"radial_velocity_km_s":45.6,"spectral_type_source":"SIMBAD (2011ApJS..193...24S, quality C)","surface_gravity_log_g":3.618,"surface_temperature_k":19412,"proper_motion_ra_mas_yr":-0.67,"proper_motion_dec_mas_yr":-0.04,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: above 7,500 K GSP-Phot's temperature and extinction are degenerate"},"designations":[{"catalog":"HD","designation":"HD 52533"},{"catalog":"HIP","designation":"HIP 33836"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-02T19:50:56.720Z","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."}