{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.663","julian_year":2026.663,"time":"2026-08-31T06:44:35.943Z","years_from_j2000":26.663,"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-104147","name":"HD 104147","class":"a2_white_star","category":"star","object_type":"A2 white star","mag":8.07,"mag_band":"V","abs_mag":0.765,"abs_mag_band":"V","distance_ly":942.6483566547334,"distance_method":"parallax","ra_deg":180.04503,"dec_deg":86.994433,"epoch_ra_deg":180.415745,"epoch_dec_deg":86.844936,"epoch_moved_arcsec":1.032,"pm_ra_mas_yr":-38.4,"pm_dec_mas_yr":-4.73,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Ursa Minor","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-104147","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"12002+8700","age_years":214824940,"companions":[{"measured":2021,"magnitude":9.29,"components":null,"discoverer_code":"STF1583","separation_arcsec":11.3,"position_angle_deg":285}],"mass_solar":2.497,"radius_solar":2.026,"spectral_type":"A2","color_index_bv":0.135,"luminosity_solar":43.05266104917108,"variable_mag_max":8.043,"variable_mag_min":8.193,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1993yCat.3135....0C, quality E)","surface_gravity_log_g":4.175,"surface_temperature_k":10409,"proper_motion_ra_mas_yr":-38.4,"proper_motion_dec_mas_yr":-4.73,"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; Gaia's classifier calls the source a binary, which GSP-Phot fitted as one star","bolometric_luminosity_solar":45.818},"designations":[{"catalog":"HD","designation":"HD 104147"},{"catalog":"HIP","designation":"HIP 58531"}],"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."}