{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.674","julian_year":2026.674,"time":"2026-09-04T06:55:23.909Z","years_from_j2000":26.674,"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-17520","name":"HD 17520","class":"o9_2ve_o8vz_blue_main_sequence_star","category":"star","object_type":"O9.2Ve+O8Vz blue main-sequence star","mag":8.23,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":42.810225,"dec_deg":60.386063,"epoch_ra_deg":43.331512,"epoch_dec_deg":60.49679,"epoch_moved_arcsec":0.287,"pm_ra_mas_yr":8.08,"pm_dec_mas_yr":-7.13,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Cassiopeia","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-17520","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"02512+6023","companions":[{"measured":2018,"magnitude":9.35,"components":"AB","discoverer_code":"BU 1316","separation_arcsec":0.3,"position_angle_deg":230},{"measured":2008,"magnitude":14.6,"components":"AO","discoverer_code":"MZA  12","separation_arcsec":5.1,"position_angle_deg":299},{"measured":2016,"magnitude":11.3,"components":"AB,C","discoverer_code":"D  9001","separation_arcsec":10.8,"position_angle_deg":20},{"measured":2016,"magnitude":11.5,"components":"AB,D","discoverer_code":"D  9001","separation_arcsec":20.1,"position_angle_deg":11},{"measured":2016,"magnitude":12.6,"components":"AB,G","discoverer_code":"ABH  15","separation_arcsec":23.9,"position_angle_deg":134},{"measured":2016,"magnitude":13.4,"components":"AB,E","discoverer_code":"ABH  15","separation_arcsec":26.9,"position_angle_deg":324},{"measured":2016,"magnitude":13.6,"components":"AB,H","discoverer_code":"ABH  15","separation_arcsec":30.6,"position_angle_deg":168},{"measured":2016,"magnitude":13,"components":"AB,F","discoverer_code":"ABH  15","separation_arcsec":36.6,"position_angle_deg":34},{"measured":2016,"magnitude":13.2,"components":"AB,I","discoverer_code":"ABH  15","separation_arcsec":40.6,"position_angle_deg":183},{"measured":2016,"magnitude":13,"components":"AB,K","discoverer_code":"ABH  15","separation_arcsec":63.7,"position_angle_deg":134},{"measured":2016,"magnitude":13.45,"components":"AB,N","discoverer_code":"ABH  15","separation_arcsec":71.4,"position_angle_deg":157},{"measured":2016,"magnitude":13.1,"components":"AB,J","discoverer_code":"ABH  15","separation_arcsec":71.8,"position_angle_deg":220},{"measured":2016,"magnitude":12.8,"components":"AB,L","discoverer_code":"ABH  15","separation_arcsec":85,"position_angle_deg":138},{"measured":2016,"magnitude":12.4,"components":"AB,M","discoverer_code":"ABH  15","separation_arcsec":90.1,"position_angle_deg":67}],"spectral_type":"O9.2Ve+O8Vz","color_index_bv":0.257,"radial_velocity_km_s":-44.5,"spectral_type_source":"SIMBAD (2021A&A...646A..11M, quality C)","proper_motion_ra_mas_yr":8.08,"proper_motion_dec_mas_yr":-7.13},"designations":[{"catalog":"HD","designation":"HD 17520"},{"catalog":"HIP","designation":"HIP 13308"}],"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."}