{"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":"2026-08-27T21:57:51.512Z","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-100203","name":"HD 100203","class":"f8vmf5_yellow_white_main_sequence_star","category":"star","object_type":"F8VmF5 yellow-white main-sequence star","mag":5.46,"mag_band":"V","abs_mag":3.225,"abs_mag_band":"V","distance_ly":91.283668526229,"distance_method":"parallax","ra_deg":173.086455,"dec_deg":61.08252,"epoch_ra_deg":173.465907,"epoch_dec_deg":60.933669,"epoch_moved_arcsec":2.564,"pm_ra_mas_yr":-14.21,"pm_dec_mas_yr":-95.13,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Ursa Major","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-100203","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"11323+6105","companions":[{"measured":2025,"magnitude":7.55,"components":"AB","discoverer_code":"STT 235","separation_arcsec":1,"position_angle_deg":59},{"measured":2013,"magnitude":11.3,"components":"AB,C","discoverer_code":"ABT   8","separation_arcsec":194.6,"position_angle_deg":97}],"spectral_type":"F8VmF5","uncertainties":{"metallicity_fe_h":[0.03,0.03]},"color_index_bv":0.515,"luminosity_solar":4.46683592150963,"metallicity_fe_h":-0.36,"radial_velocity_km_s":-47.9,"spectral_type_source":"SIMBAD (2001AJ....121.2148G, quality C)","surface_gravity_log_g":3.99,"surface_temperature_k":6155,"metallicity_fe_h_source":"Median of 2 spectroscopic determinations in 3 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":-14.21,"proper_motion_dec_mas_yr":-95.13,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"Gliese","designation":"Gl 431.1A"},{"catalog":"HD","designation":"HD 100203"},{"catalog":"HIP","designation":"HIP 56290"},{"catalog":"HR","designation":"HR 4439"}],"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."}