{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.686","julian_year":2026.686,"time":"2026-09-08T11:17:57.002Z","years_from_j2000":26.686,"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-170580","name":"HD 170580","class":"b2v_blue_white_main_sequence_star","category":"star","object_type":"B2V blue-white main-sequence star","mag":6.66,"mag_band":"V","abs_mag":-1.868,"abs_mag_band":"V","distance_ly":1655.6160874958252,"distance_method":"parallax","ra_deg":277.52133000000003,"dec_deg":4.065354,"epoch_ra_deg":277.855041,"epoch_dec_deg":4.083033,"epoch_moved_arcsec":0.149,"pm_ra_mas_yr":-0.08,"pm_dec_mas_yr":-5.59,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Ophiuchus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-170580","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"18301+0404","companions":[{"measured":2024,"magnitude":9.6,"components":"Aa,Ab","discoverer_code":"CHR  72","separation_arcsec":0.1,"position_angle_deg":297},{"measured":2009,"magnitude":11.28,"components":"AB","discoverer_code":"STF2322","separation_arcsec":19.8,"position_angle_deg":172},{"measured":2015,"magnitude":12.79,"components":"AC","discoverer_code":"STF2322","separation_arcsec":67.2,"position_angle_deg":295},{"measured":2009,"magnitude":13.39,"components":"AD","discoverer_code":"STF2322","separation_arcsec":85.3,"position_angle_deg":197}],"mass_solar":6.556,"radius_solar":6.399,"spectral_type":"B2V","color_index_bv":0.11,"luminosity_solar":486.63125607319915,"radial_velocity_km_s":-22,"spectral_type_source":"SIMBAD (1968ApJS...17..371L, quality C)","surface_gravity_log_g":3.611,"surface_temperature_k":16386,"proper_motion_ra_mas_yr":-0.08,"proper_motion_dec_mas_yr":-5.59,"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","bolometric_luminosity_solar":2853.7722},"designations":[{"catalog":"HD","designation":"HD 170580"},{"catalog":"HIP","designation":"HIP 90676"},{"catalog":"HR","designation":"HR 6941"}],"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."}