{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.672","julian_year":2026.672,"time":"2026-09-03T10:43:32.536Z","years_from_j2000":26.672,"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-10859","name":"τ¹ Hyi","class":"g6_8iii_yellow_giant","category":"star","object_type":"G6/8III yellow giant","mag":6.33,"mag_band":"V","abs_mag":0.92,"abs_mag_band":"V","distance_ly":393.90851590346483,"distance_method":"parallax","ra_deg":25.33884,"dec_deg":-79.1482,"epoch_ra_deg":25.364221,"epoch_dec_deg":-79.01196,"epoch_moved_arcsec":1.7,"pm_ra_mas_yr":59.76,"pm_dec_mas_yr":22.13,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Hydrus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-10859","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"01414-7909","companions":[{"measured":2025,"magnitude":8.69,"components":"Aa,Ab","discoverer_code":"HDS 223","separation_arcsec":0.1,"position_angle_deg":234},{"measured":2015,"magnitude":12.2,"components":"AB","discoverer_code":"HJ 3467","separation_arcsec":15.9,"position_angle_deg":350}],"spectral_type":"G6/8III","color_index_bv":0.947,"luminosity_solar":37.32501577957206,"radial_velocity_km_s":2,"spectral_type_source":"SIMBAD (1975MSS...C01....0H, quality D)","proper_motion_ra_mas_yr":59.76,"proper_motion_dec_mas_yr":22.13},"designations":[{"catalog":"Bayer/Flamsteed","designation":"Tau1 Hyi"},{"catalog":"HD","designation":"HD 10859"},{"catalog":"HIP","designation":"HIP 7879"},{"catalog":"HR","designation":"HR 516"}],"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."}