{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.680","julian_year":2026.68,"time":"2026-09-06T09:11:45.471Z","years_from_j2000":26.68,"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-133640","name":"44 Boo","class":"g0vn_yellow_main_sequence_star","category":"star","object_type":"G0Vn yellow main-sequence star","mag":4.83,"mag_band":"V","abs_mag":4.344,"abs_mag_band":"V","distance_ly":40.79498741205483,"distance_method":"parallax","ra_deg":225.94761,"dec_deg":47.65406,"epoch_ra_deg":226.170817,"epoch_dec_deg":47.548767,"epoch_moved_arcsec":11.65,"pm_ra_mas_yr":-436.24,"pm_dec_mas_yr":18.94,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Boötes","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-133640","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"15038+4739","companions":[{"measured":2025,"magnitude":6.1,"components":null,"discoverer_code":"STF1909","separation_arcsec":0.8,"position_angle_deg":219}],"spectral_type":"G0Vn","uncertainties":{"metallicity_fe_h":[0.098,0.098]},"color_index_bv":0.647,"luminosity_solar":1.593675881028766,"metallicity_fe_h":-0.29,"variable_mag_max":4.793,"variable_mag_min":4.943,"radial_velocity_km_s":-29.7,"spectral_type_source":"SIMBAD (2001AJ....121.2148G, quality C)","variable_designation":"I Boo","surface_gravity_log_g":4.29,"surface_temperature_k":5740,"metallicity_fe_h_source":"Median of 6 spectroscopic determinations in 8 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":-436.24,"proper_motion_dec_mas_yr":18.94,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"44 Boo"},{"catalog":"Gliese","designation":"Gl 575A"},{"catalog":"HD","designation":"HD 133640"},{"catalog":"HIP","designation":"HIP 73695"},{"catalog":"HR","designation":"HR 5618"},{"catalog":"Variable star","designation":"I Boo"}],"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."}