{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.686","julian_year":2026.686,"time":"2026-09-08T12:28:51.775Z","years_from_j2000":26.686,"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-122556","name":"HD 122556","class":"f6v_yellow_white_main_sequence_star","category":"star","object_type":"F6V yellow-white main-sequence star","mag":8.89,"mag_band":"V","abs_mag":2.7,"abs_mag_band":"V","distance_ly":564.2844537132487,"distance_method":"parallax","ra_deg":210.91719,"dec_deg":-46.301866,"epoch_ra_deg":211.339607,"epoch_dec_deg":-46.431236,"epoch_moved_arcsec":2.315,"pm_ra_mas_yr":-85.29,"pm_dec_mas_yr":-15.8,"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-122556","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"14037-4618","age_years":5563915700,"companions":[{"measured":2016,"magnitude":9.91,"components":null,"discoverer_code":"COO 164","separation_arcsec":2.8,"position_angle_deg":136}],"mass_solar":1.176,"radius_solar":1.785,"spectral_type":"F6V","color_index_bv":0.543,"luminosity_solar":7.244359600749899,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1978MSS...C02....0H, quality C)","surface_gravity_log_g":3.94,"surface_temperature_k":5989,"proper_motion_ra_mas_yr":-85.29,"proper_motion_dec_mas_yr":-15.8,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":3.6464},"designations":[{"catalog":"HD","designation":"HD 122556"},{"catalog":"HIP","designation":"HIP 68694"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-02T19:50:56.720Z","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."}