{"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":"2026-09-02T22:17:58.707Z","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-38545","name":"131 Tau","class":"a3vn_white_main_sequence_star","category":"star","object_type":"A3Vn white main-sequence star","mag":5.72,"mag_band":"V","abs_mag":0.631,"abs_mag_band":"V","distance_ly":339.746335507067,"distance_method":"parallax","ra_deg":86.804805,"dec_deg":14.488322,"epoch_ra_deg":87.187415,"epoch_dec_deg":14.49814,"epoch_moved_arcsec":1.133,"pm_ra_mas_yr":3.84,"pm_dec_mas_yr":-42.3,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Taurus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-38545","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"05472+1429","companions":[{"measured":2016,"magnitude":6.87,"components":null,"discoverer_code":"CHR 160","separation_arcsec":0.2,"position_angle_deg":193}],"spectral_type":"A3Vn","color_index_bv":0.077,"luminosity_solar":48.70796664925366,"metallicity_fe_h":-0.3,"radial_velocity_km_s":21,"spectral_type_source":"SIMBAD (quality C)","surface_gravity_log_g":3.6,"surface_temperature_k":8880,"metallicity_fe_h_source":"One spectroscopic determination, compiled from the literature (PASTEL, Soubiran+ 2016)","proper_motion_ra_mas_yr":3.84,"proper_motion_dec_mas_yr":-42.3,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"131 Tau"},{"catalog":"HD","designation":"HD 38545"},{"catalog":"HIP","designation":"HIP 27316"},{"catalog":"HR","designation":"HR 1989"}],"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."}