{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.684","julian_year":2026.684,"time":"2026-09-07T16:59:52.646Z","years_from_j2000":26.684,"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-164427","name":"HD 164427","class":"g0_v_yellow_star","category":"star","object_type":"G0+V yellow star","mag":6.88,"mag_band":"V","abs_mag":3.981,"abs_mag_band":"V","distance_ly":123.91952799332176,"distance_method":"parallax","ra_deg":271.17795,"dec_deg":-59.209575,"epoch_ra_deg":271.770377,"epoch_dec_deg":-59.208417,"epoch_moved_arcsec":5.473,"pm_ra_mas_yr":-198.46,"pm_dec_mas_yr":-51.79,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Pavo","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-164427","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"18047-5913","companions":[{"measured":2016,"magnitude":12.6,"components":null,"discoverer_code":"HJ 5006","separation_arcsec":28.8,"position_angle_deg":336}],"spectral_type":"G0+V","uncertainties":{"metallicity_fe_h":[0.074,0.074]},"color_index_bv":0.624,"luminosity_solar":2.2263836295529074,"metallicity_fe_h":0.1,"radial_velocity_km_s":3.3,"spectral_type_source":"SIMBAD (2006AJ....132..161G, quality C)","surface_gravity_log_g":4.2,"surface_temperature_k":5926,"metallicity_fe_h_source":"Median of 3 spectroscopic determinations in 4 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":-198.46,"proper_motion_dec_mas_yr":-51.79,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"HD","designation":"HD 164427"},{"catalog":"HIP","designation":"HIP 88531"}],"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."}