{"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":"2026-08-31T21:25:22.027Z","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-313","name":"HD 313","class":"a3_white_star","category":"star","object_type":"A3 white star","mag":7.66,"mag_band":"V","abs_mag":1.533,"abs_mag_band":"V","distance_ly":548.1618916499547,"distance_method":"parallax","ra_deg":1.96242,"dec_deg":38.721732,"epoch_ra_deg":2.308867,"epoch_dec_deg":38.870994,"epoch_moved_arcsec":0.748,"pm_ra_mas_yr":-14.56,"pm_dec_mas_yr":-23.97,"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-313","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"age_years":221870570,"mass_solar":2.21,"radius_solar":1.748,"spectral_type":"A3","color_index_bv":0.181,"luminosity_solar":21.222668969007817,"radial_velocity_km_s":-13,"spectral_type_source":"SIMBAD (1993yCat.3135....0C, quality E)","surface_gravity_log_g":4.278,"surface_temperature_k":9696,"proper_motion_ra_mas_yr":-14.56,"proper_motion_dec_mas_yr":-23.97,"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","bolometric_luminosity_solar":26.9134},"designations":[{"catalog":"HD","designation":"HD 313"},{"catalog":"HIP","designation":"HIP 640"}],"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."}