{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.668","julian_year":2026.668,"time":"2026-09-02T00:49:44.060Z","years_from_j2000":26.668,"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-18326","name":"HD 18326","class":"o6_5v_f_z_o9_b0v_blue_main_sequence_star","category":"star","object_type":"O6.5V((f))z+O9/B0V: blue main-sequence star","mag":7.93,"mag_band":"V","abs_mag":-0.124,"abs_mag_band":"V","distance_ly":1331.2506344491246,"distance_method":"parallax","ra_deg":44.84655,"dec_deg":60.566529,"epoch_ra_deg":45.375728,"epoch_dec_deg":60.67364,"epoch_moved_arcsec":0.04,"pm_ra_mas_yr":-0.62,"pm_dec_mas_yr":-1.36,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Cassiopeia","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-18326","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"02594+6034","companions":[{"measured":2016,"magnitude":16.3,"components":"AB","discoverer_code":"TRN  14","separation_arcsec":2.5,"position_angle_deg":358},{"measured":2015,"magnitude":12.9,"components":"AC","discoverer_code":"MZA  14","separation_arcsec":8.1,"position_angle_deg":354},{"measured":2015,"magnitude":14,"components":"AE","discoverer_code":"MZA  14","separation_arcsec":8.4,"position_angle_deg":249},{"measured":2015,"magnitude":14.3,"components":"AD","discoverer_code":"MZA  14","separation_arcsec":12.5,"position_angle_deg":327},{"measured":2015,"magnitude":14,"components":"AG","discoverer_code":"SS    5","separation_arcsec":22.9,"position_angle_deg":26},{"measured":2016,"magnitude":11.4,"components":"AH","discoverer_code":"SS    5","separation_arcsec":25,"position_angle_deg":50},{"measured":2015,"magnitude":14.1,"components":"AI","discoverer_code":"SS    5","separation_arcsec":26.9,"position_angle_deg":153},{"measured":2015,"magnitude":14.5,"components":"AJ","discoverer_code":"SS    5","separation_arcsec":33.7,"position_angle_deg":135},{"measured":2016,"magnitude":10.4,"components":"AK","discoverer_code":"SS    5","separation_arcsec":36.6,"position_angle_deg":122}],"spectral_type":"O6.5V((f))z+O9/B0V:","color_index_bv":0.301,"luminosity_solar":97.63375665826416,"radial_velocity_km_s":-40,"spectral_type_source":"SIMBAD (2014ApJS..211...10S, quality C)","proper_motion_ra_mas_yr":-0.62,"proper_motion_dec_mas_yr":-1.36},"designations":[{"catalog":"HD","designation":"HD 18326"},{"catalog":"HIP","designation":"HIP 13924"}],"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."}