{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.671","julian_year":2026.671,"time":"2026-09-03T00:01:54.222Z","years_from_j2000":26.671,"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-18783","name":"HD 18783","class":"f5_yellow_white_star","category":"star","object_type":"F5 yellow-white star","mag":8.24,"mag_band":"V","abs_mag":3.941,"abs_mag_band":"V","distance_ly":236.1740731376042,"distance_method":"parallax","ra_deg":45.46077,"dec_deg":16.518033,"epoch_ra_deg":45.837545,"epoch_dec_deg":16.623733,"epoch_moved_arcsec":5.144,"pm_ra_mas_yr":183.55,"pm_dec_mas_yr":-59.25,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Aries","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-18783","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"03018+1631","age_years":3391862600,"companions":[{"measured":2016,"magnitude":14.97,"components":null,"discoverer_code":"NSN 535","separation_arcsec":16.2,"position_angle_deg":309}],"mass_solar":1.172,"radius_solar":1.314,"spectral_type":"F5","color_index_bv":0.504,"luminosity_solar":2.3099362801731855,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1993yCat.3135....0C, quality E)","surface_gravity_log_g":4.163,"surface_temperature_k":6212,"proper_motion_ra_mas_yr":183.55,"proper_motion_dec_mas_yr":-59.25,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: Gaia's classifier calls the source a binary, which GSP-Phot fitted as one star","bolometric_luminosity_solar":2.3087},"designations":[{"catalog":"HD","designation":"HD 18783"},{"catalog":"HIP","designation":"HIP 14098"}],"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."}