{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.668","julian_year":2026.668,"time":"2026-09-02T00:40:40.171Z","years_from_j2000":26.668,"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-201647","name":"HD 201647","class":"f5v_yellow_white_main_sequence_star","category":"star","object_type":"F5V yellow-white main-sequence star","mag":5.83,"mag_band":"V","abs_mag":3.327,"abs_mag_band":"V","distance_ly":103.27937394227311,"distance_method":"parallax","ra_deg":318.05709,"dec_deg":-40.269362,"epoch_ra_deg":318.48722,"epoch_dec_deg":-40.160975,"epoch_moved_arcsec":6.049,"pm_ra_mas_yr":57.41,"pm_dec_mas_yr":-219.43,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Microscopium","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-201647","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"21122-4016","age_years":2643953000,"companions":[{"measured":2010,"magnitude":13.1,"components":"AF","discoverer_code":"CRU9018","separation_arcsec":122.7,"position_angle_deg":326},{"measured":2010,"magnitude":13.1,"components":"AB","discoverer_code":"CRU9018","separation_arcsec":122.8,"position_angle_deg":212},{"measured":2010,"magnitude":14.2,"components":"AC","discoverer_code":"CRU9018","separation_arcsec":146,"position_angle_deg":237},{"measured":2010,"magnitude":13,"components":"AD","discoverer_code":"CRU9018","separation_arcsec":180.1,"position_angle_deg":250},{"measured":2010,"magnitude":14,"components":"AE","discoverer_code":"CRU9018","separation_arcsec":219.6,"position_angle_deg":268}],"mass_solar":1.304,"radius_solar":1.564,"spectral_type":"F5V","color_index_bv":0.45,"luminosity_solar":4.066305463404283,"radial_velocity_km_s":6.3,"spectral_type_source":"SIMBAD (2006AJ....132..161G, quality C)","surface_gravity_log_g":4.131,"surface_temperature_k":6449,"proper_motion_ra_mas_yr":57.41,"proper_motion_dec_mas_yr":-219.43,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":3.7855},"designations":[{"catalog":"Gliese","designation":"GJ 9726"},{"catalog":"HD","designation":"HD 201647"},{"catalog":"HIP","designation":"HIP 104680"},{"catalog":"HR","designation":"HR 8100"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-01T22:58:55.274Z","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."}