{"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":"2026-09-04T17:58:40.233Z","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-223598","name":"HD 223598","class":"f6v_yellow_white_main_sequence_star","category":"star","object_type":"F6V yellow-white main-sequence star","mag":8.88,"mag_band":"V","abs_mag":3.685,"abs_mag_band":"V","distance_ly":356.84508360886724,"distance_method":"parallax","ra_deg":357.73461,"dec_deg":-33.562535,"epoch_ra_deg":358.083565,"epoch_dec_deg":-33.413357,"epoch_moved_arcsec":1.007,"pm_ra_mas_yr":-31.36,"pm_dec_mas_yr":-21.01,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Sculptor","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-223598","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"23509-3334","age_years":3730312300,"companions":[{"measured":2016,"magnitude":11.59,"components":null,"discoverer_code":"SEE 495","separation_arcsec":2.9,"position_angle_deg":14}],"mass_solar":1.292,"radius_solar":1.736,"spectral_type":"F6V","color_index_bv":0.504,"luminosity_solar":2.9241523778433347,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1982MSS...C03....0H, quality C)","surface_gravity_log_g":3.974,"surface_temperature_k":6080,"proper_motion_ra_mas_yr":-31.36,"proper_motion_dec_mas_yr":-21.01,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":3.8499},"designations":[{"catalog":"HD","designation":"HD 223598"},{"catalog":"HIP","designation":"HIP 117598"}],"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."}