{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.686","julian_year":2026.686,"time":"2026-09-08T09:33:28.586Z","years_from_j2000":26.686,"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":"hip-58439","name":"HIP 58439","class":"ob_blue_star","category":"star","object_type":"OB blue star","mag":10.69,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":179.74985999999998,"dec_deg":-73.430092,"epoch_ra_deg":180.085451,"epoch_dec_deg":-73.579734,"epoch_moved_arcsec":0.249,"pm_ra_mas_yr":-6.35,"pm_dec_mas_yr":-6.86,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Musca","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hip-58439","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"radius_solar":5.634,"spectral_type":"OB","color_index_bv":-0.077,"variable_mag_max":10.619,"variable_mag_min":10.739,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1971PW&SO...1a...1S, quality E)","surface_gravity_log_g":3.937,"surface_temperature_k":25901,"proper_motion_ra_mas_yr":-6.35,"proper_motion_dec_mas_yr":-6.86,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: above 7,500 K GSP-Phot's temperature and extinction are degenerate"},"designations":[{"catalog":"HIP","designation":"HIP 58439"}],"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."}