{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.654","julian_year":2026.654,"time":"2026-08-27T21:57:51.126Z","years_from_j2000":26.654,"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-40801","name":"38 Aur","class":"k0iii_orange_giant","category":"star","object_type":"K0III orange giant","mag":6.08,"mag_band":"V","abs_mag":2.008,"abs_mag_band":"V","distance_ly":212.7570236866752,"distance_method":"parallax","ra_deg":90.82473,"dec_deg":42.911564,"epoch_ra_deg":91.308677,"epoch_dec_deg":42.910111,"epoch_moved_arcsec":4.512,"pm_ra_mas_yr":104.99,"pm_dec_mas_yr":-132.78,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Auriga","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-40801","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"06033+4255","companions":[{"measured":2015,"magnitude":16.8,"components":null,"discoverer_code":"LEP  20","separation_arcsec":152,"position_angle_deg":335}],"spectral_type":"K0III","uncertainties":{"metallicity_fe_h":[0.072,0.072]},"color_index_bv":0.979,"luminosity_solar":13.702505971242443,"metallicity_fe_h":-0.17,"radial_velocity_km_s":38,"spectral_type_source":"SIMBAD (1955ApJS....2..195R, quality C)","surface_gravity_log_g":2.85,"surface_temperature_k":4787,"metallicity_fe_h_source":"Median of 6 spectroscopic determinations in 6 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":104.99,"proper_motion_dec_mas_yr":-132.78,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"38 Aur"},{"catalog":"HD","designation":"HD 40801"},{"catalog":"HIP","designation":"HIP 28677"},{"catalog":"HR","designation":"HR 2119"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-27T19:16:43.430Z","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."}