{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.654","julian_year":2026.654,"time":"2026-08-27T20:23:09.442Z","years_from_j2000":26.654,"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-139691","name":"HD 139691","class":"f2v_yellow_white_main_sequence_star","category":"star","object_type":"F2V yellow-white main-sequence star","mag":7.07,"mag_band":"V","abs_mag":1.858,"abs_mag_band":"V","distance_ly":359.59914806230745,"distance_method":"parallax","ra_deg":234.55383,"dec_deg":36.24683,"epoch_ra_deg":234.808949,"epoch_dec_deg":36.1588,"epoch_moved_arcsec":1.84,"pm_ra_mas_yr":-59.81,"pm_dec_mas_yr":34.48,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Corona Borealis","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-139691","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"15382+3615","age_years":2214048000,"companions":[{"measured":2016,"magnitude":9.87,"components":"AB","discoverer_code":"HU 1167","separation_arcsec":1.4,"position_angle_deg":80},{"measured":2021,"magnitude":8.06,"components":"AC","discoverer_code":"STF1964","separation_arcsec":15,"position_angle_deg":86},{"measured":2021,"magnitude":9.02,"components":"AD","discoverer_code":"STF1964","separation_arcsec":15.8,"position_angle_deg":80}],"mass_solar":1.51,"radius_solar":2.228,"spectral_type":"F2V","color_index_bv":1.7,"luminosity_solar":15.732581854464675,"variable_mag_max":6.941,"variable_mag_min":7.421,"radial_velocity_km_s":-29,"spectral_type_source":"SIMBAD (2008ApJS..176..216A, quality C)","surface_gravity_log_g":3.891,"surface_temperature_k":6405,"proper_motion_ra_mas_yr":-59.81,"proper_motion_dec_mas_yr":34.48,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":7.4657},"designations":[{"catalog":"HD","designation":"HD 139691"},{"catalog":"HIP","designation":"HIP 76563"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-27T19:16:43.430Z","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."}