{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.668","julian_year":2026.668,"time":"2026-09-02T00:20:59.833Z","years_from_j2000":26.668,"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-17864","name":"HD 17864","class":"a0v_white_main_sequence_star","category":"star","object_type":"A0V white main-sequence star","mag":6.36,"mag_band":"V","abs_mag":1.635,"abs_mag_band":"V","distance_ly":287.3623596819808,"distance_method":"parallax","ra_deg":42.699164999999994,"dec_deg":-39.932224,"epoch_ra_deg":42.960096,"epoch_dec_deg":-39.821113,"epoch_moved_arcsec":1.16,"pm_ra_mas_yr":42.3,"pm_dec_mas_yr":-10.16,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Eridanus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-17864","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"02508-3956","age_years":513047100,"companions":[{"measured":1991,"magnitude":10.24,"components":"Aa,Ab","discoverer_code":"HDS 368","separation_arcsec":0.3,"position_angle_deg":223}],"mass_solar":2.061,"radius_solar":1.977,"spectral_type":"A0V","color_index_bv":0.04,"luminosity_solar":19.31968317016924,"radial_velocity_km_s":19,"spectral_type_source":"SIMBAD (1978MSS...C02....0H, quality C)","surface_gravity_log_g":4.062,"surface_temperature_k":9998,"proper_motion_ra_mas_yr":42.3,"proper_motion_dec_mas_yr":-10.16,"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":22.9707},"designations":[{"catalog":"HD","designation":"HD 17864"},{"catalog":"HIP","designation":"HIP 13271"},{"catalog":"HR","designation":"HR 853"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-01T22:58:55.274Z","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."}