{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.679","julian_year":2026.679,"time":"2026-09-05T22:47:16.708Z","years_from_j2000":26.679,"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-143538","name":"HD 143538","class":"f0v_yellow_white_main_sequence_star","category":"star","object_type":"F0V yellow-white main-sequence star","mag":8.64,"mag_band":"V","abs_mag":3.508,"abs_mag_band":"V","distance_ly":346.60605644320555,"distance_method":"parallax","ra_deg":240.5772,"dec_deg":-35.269932,"epoch_ra_deg":241.012888,"epoch_dec_deg":-35.345114,"epoch_moved_arcsec":0.886,"pm_ra_mas_yr":-16.27,"pm_dec_mas_yr":-28.96,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Lupus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-143538","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"16023-3516","age_years":1541192200,"companions":[{"measured":2012,"magnitude":15.3,"components":"AB","discoverer_code":"JNN 217","separation_arcsec":2,"position_angle_deg":71},{"measured":2012,"magnitude":18,"components":"AD","discoverer_code":"JNN 217","separation_arcsec":3.8,"position_angle_deg":283},{"measured":2012,"magnitude":18.2,"components":"AF","discoverer_code":"JNN 217","separation_arcsec":4,"position_angle_deg":106},{"measured":2016,"magnitude":15.4,"components":"AC","discoverer_code":"JNN 217","separation_arcsec":4.3,"position_angle_deg":185},{"measured":2012,"magnitude":18.1,"components":"AE","discoverer_code":"JNN 217","separation_arcsec":4.4,"position_angle_deg":54}],"mass_solar":1.4,"radius_solar":1.567,"spectral_type":"F0V","color_index_bv":0.387,"luminosity_solar":3.4419138826842897,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1982MSS...C03....0H, quality C)","surface_gravity_log_g":4.133,"surface_temperature_k":6803,"proper_motion_ra_mas_yr":-16.27,"proper_motion_dec_mas_yr":-28.96,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":4.7144},"designations":[{"catalog":"HD","designation":"HD 143538"},{"catalog":"HIP","designation":"HIP 78555"}],"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."}