{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.676","julian_year":2026.676,"time":"2026-09-04T21:58:59.135Z","years_from_j2000":26.676,"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-159704","name":"HD 159704","class":"g8iv_v_yellow_subgiant","category":"star","object_type":"G8IV/V yellow subgiant","mag":6.68,"mag_band":"V","abs_mag":3.293,"abs_mag_band":"V","distance_ly":155.16465666583036,"distance_method":"parallax","ra_deg":264.46338,"dec_deg":-37.861396,"epoch_ra_deg":264.923049,"epoch_dec_deg":-37.878475,"epoch_moved_arcsec":3.502,"pm_ra_mas_yr":-6.77,"pm_dec_mas_yr":-131.09,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Scorpius","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-159704","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"17379-3752","companions":[{"measured":2025,"magnitude":8.68,"components":"AB","discoverer_code":"I   247","separation_arcsec":0.3,"position_angle_deg":317},{"measured":2025,"magnitude":9,"components":"AC","discoverer_code":"I   247","separation_arcsec":0.3,"position_angle_deg":109}],"spectral_type":"G8IV/V","color_index_bv":0.757,"luminosity_solar":4.195657223387252,"radial_velocity_km_s":2.8,"spectral_type_source":"SIMBAD (1982MSS...C03....0H, quality D)","surface_temperature_k":5417,"proper_motion_ra_mas_yr":-6.77,"proper_motion_dec_mas_yr":-131.09,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"Gliese","designation":"Gl 683.2A"},{"catalog":"HD","designation":"HD 159704"},{"catalog":"HIP","designation":"HIP 86286"}],"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."}