{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.669","julian_year":2026.669,"time":"2026-09-02T04:53:33.935Z","years_from_j2000":26.669,"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-109409","name":"HD 109409","class":"g3iv_yellow_subgiant","category":"star","object_type":"G3IV yellow subgiant","mag":5.76,"mag_band":"V","abs_mag":3.499,"abs_mag_band":"V","distance_ly":92.36944310764804,"distance_method":"parallax","ra_deg":188.67672,"dec_deg":-44.673018,"epoch_ra_deg":189.040486,"epoch_dec_deg":-44.822588,"epoch_moved_arcsec":5.86,"pm_ra_mas_yr":-75.86,"pm_dec_mas_yr":-206.23,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Centaurus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-109409","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"12347-4440","age_years":6697785000,"companions":[{"measured":1929,"magnitude":12.3,"components":"AB","discoverer_code":"B  1718","separation_arcsec":1,"position_angle_deg":0},{"measured":2016,"magnitude":16.2,"components":"AC","discoverer_code":"NSN 406","separation_arcsec":38.1,"position_angle_deg":56}],"mass_solar":1.137,"radius_solar":1.853,"spectral_type":"G3IV","uncertainties":{"metallicity_fe_h":[0.033,0.033]},"color_index_bv":0.683,"luminosity_solar":3.470563540079875,"metallicity_fe_h":0.31,"radial_velocity_km_s":18,"spectral_type_source":"SIMBAD (2006AJ....132..161G, quality C)","surface_gravity_log_g":4.026,"surface_temperature_k":5721,"metallicity_fe_h_source":"Median of 7 spectroscopic determinations in 6 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":-75.86,"proper_motion_dec_mas_yr":-206.23,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":3.4037},"designations":[{"catalog":"HD","designation":"HD 109409"},{"catalog":"HIP","designation":"HIP 61379"},{"catalog":"HR","designation":"HR 4788"}],"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."}