{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.683","julian_year":2026.683,"time":"2026-09-07T09:23:41.972Z","years_from_j2000":26.683,"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-167264","name":"15 Sgr","class":"o9_7iab_blue_supergiant","category":"star","object_type":"O9.7Iab blue supergiant","mag":5.29,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":273.80377500000003,"dec_deg":-20.72827,"epoch_ra_deg":274.204564,"epoch_dec_deg":-20.720129,"epoch_moved_arcsec":0.084,"pm_ra_mas_yr":2.9,"pm_dec_mas_yr":-1.26,"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/hd-167264","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"18152-2044","companions":[{"measured":2013,"magnitude":10.6,"components":"AB","discoverer_code":"TOK  59","separation_arcsec":1.3,"position_angle_deg":77},{"measured":2012,"magnitude":12.91,"components":"AC","discoverer_code":"SNA  82","separation_arcsec":2.3,"position_angle_deg":356},{"measured":2012,"magnitude":12.18,"components":"AD","discoverer_code":"SNA  82","separation_arcsec":7.1,"position_angle_deg":108}],"radius_solar":9.187,"spectral_type":"O9.7Iab","color_index_bv":0.007,"radial_velocity_km_s":-6,"spectral_type_source":"SIMBAD (2014ApJS..211...10S, quality C)","surface_gravity_log_g":3.599,"surface_temperature_k":25210,"proper_motion_ra_mas_yr":2.9,"proper_motion_dec_mas_yr":-1.26,"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; Gaia's classifier calls the source a binary, which GSP-Phot fitted as one star"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"15 Sgr"},{"catalog":"HD","designation":"HD 167264"},{"catalog":"HIP","designation":"HIP 89439"},{"catalog":"HR","designation":"HR 6822"}],"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."}