{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.667","julian_year":2026.667,"time":"2026-09-01T14:27:20.767Z","years_from_j2000":26.667,"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-9747","name":"HD 9747","class":"g5_yellow_star","category":"star","object_type":"G5 yellow star","mag":7.38,"mag_band":"V","abs_mag":0.113,"abs_mag_band":"V","distance_ly":926.5805888628958,"distance_method":"parallax","ra_deg":24.094785,"dec_deg":47.325856,"epoch_ra_deg":24.503188,"epoch_dec_deg":47.462929,"epoch_moved_arcsec":0.537,"pm_ra_mas_yr":-14.73,"pm_dec_mas_yr":-13.73,"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-9747","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"age_years":455501050,"mass_solar":2.791,"radius_solar":9.928,"spectral_type":"G5","color_index_bv":0.939,"luminosity_solar":78.48741034887297,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1993yCat.3135....0C, quality E)","surface_gravity_log_g":2.782,"surface_temperature_k":5310,"proper_motion_ra_mas_yr":-14.73,"proper_motion_dec_mas_yr":-13.73,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":75.4531},"designations":[{"catalog":"HD","designation":"HD 9747"},{"catalog":"HIP","designation":"HIP 7483"}],"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."}