{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.670","julian_year":2026.67,"time":"2026-09-02T13:17:43.875Z","years_from_j2000":26.67,"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-18664","name":"HD 18664","class":"a2_white_star","category":"star","object_type":"A2 white star","mag":8.67,"mag_band":"V","abs_mag":0.851,"abs_mag_band":"V","distance_ly":1194.712116201942,"distance_method":"parallax","ra_deg":45.40095,"dec_deg":42.701545,"epoch_ra_deg":45.842209,"epoch_dec_deg":42.807732,"epoch_moved_arcsec":0.097,"pm_ra_mas_yr":-3.64,"pm_dec_mas_yr":-0.25,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Perseus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-18664","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"spectral_type":"A2","color_index_bv":0.104,"luminosity_solar":39.7740669105028,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1993yCat.3135....0C, quality E)","proper_motion_ra_mas_yr":-3.64,"proper_motion_dec_mas_yr":-0.25},"designations":[{"catalog":"HD","designation":"HD 18664"},{"catalog":"HIP","designation":"HIP 14084"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-01T22:58:55.274Z","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."}