{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.665","julian_year":2026.665,"time":"2026-08-31T23:05:26.864Z","years_from_j2000":26.665,"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-8481","name":"HD 8481","class":"g5_yellow_star","category":"star","object_type":"G5 yellow star","mag":7.85,"mag_band":"V","abs_mag":1.544,"abs_mag_band":"V","distance_ly":595.1760288723123,"distance_method":"parallax","ra_deg":21.12858,"dec_deg":39.025046,"epoch_ra_deg":21.515007,"epoch_dec_deg":39.16502,"epoch_moved_arcsec":0.379,"pm_ra_mas_yr":5.61,"pm_dec_mas_yr":-13.05,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Andromeda","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-8481","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"01245+3902","age_years":454831060,"companions":[{"measured":2015,"magnitude":9.8,"components":"AB","discoverer_code":"STTA 17","separation_arcsec":35.4,"position_angle_deg":101},{"measured":2016,"magnitude":8.47,"components":"AC","discoverer_code":"STTA 17","separation_arcsec":136.4,"position_angle_deg":347},{"measured":2015,"magnitude":11.17,"components":"AF","discoverer_code":"BKO  10","separation_arcsec":141.7,"position_angle_deg":270}],"mass_solar":2.802,"radius_solar":9.19,"spectral_type":"G5","color_index_bv":1.01,"luminosity_solar":21.00873969240991,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1993yCat.3135....0C, quality E)","surface_gravity_log_g":2.602,"surface_temperature_k":4813,"proper_motion_ra_mas_yr":5.61,"proper_motion_dec_mas_yr":-13.05,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":42.9455},"designations":[{"catalog":"HD","designation":"HD 8481"},{"catalog":"HIP","designation":"HIP 6578"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-30T09:56:50.739Z","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."}