{"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":"2026-09-02T10:20:52.462Z","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-49503","name":"HD 49503","class":"f5_6v_yellow_white_main_sequence_star","category":"star","object_type":"F5/6V yellow-white main-sequence star","mag":7.02,"mag_band":"V","abs_mag":3.648,"abs_mag_band":"V","distance_ly":154.13824254515578,"distance_method":"parallax","ra_deg":102.14898,"dec_deg":-4.075906,"epoch_ra_deg":102.482145,"epoch_dec_deg":-4.106135,"epoch_moved_arcsec":2.526,"pm_ra_mas_yr":-48.94,"pm_dec_mas_yr":-81.11,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Monoceros","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-49503","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"06486-0405","age_years":3363210700,"companions":[{"measured":2021,"magnitude":8.66,"components":"AB","discoverer_code":"A    58","separation_arcsec":5.1,"position_angle_deg":161},{"measured":2015,"magnitude":10.54,"components":"AC","discoverer_code":"GIR   1","separation_arcsec":93.5,"position_angle_deg":154},{"measured":2015,"magnitude":15.8,"components":"AD","discoverer_code":"GWP 834","separation_arcsec":169.5,"position_angle_deg":50}],"mass_solar":1.177,"radius_solar":1.319,"spectral_type":"F5/6V","color_index_bv":0.553,"luminosity_solar":3.0255198038723057,"variable_mag_max":6.99,"variable_mag_min":7.24,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1999MSS...C05....0H, quality D)","surface_gravity_log_g":4.124,"surface_temperature_k":6224,"proper_motion_ra_mas_yr":-48.94,"proper_motion_dec_mas_yr":-81.11,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: Gaia's classifier calls the source a binary, which GSP-Phot fitted as one star","bolometric_luminosity_solar":2.3612},"designations":[{"catalog":"HD","designation":"HD 49503"},{"catalog":"HIP","designation":"HIP 32644"}],"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."}