{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.664","julian_year":2026.664,"time":"2026-08-31T15:51:27.387Z","years_from_j2000":26.664,"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-166136","name":"HD 166136","class":"g3v_yellow_main_sequence_star","category":"star","object_type":"G3V yellow main-sequence star","mag":8.98,"mag_band":"V","abs_mag":3.954,"abs_mag_band":"V","distance_ly":330.117873080491,"distance_method":"parallax","ra_deg":272.69262,"dec_deg":-35.478069,"epoch_ra_deg":273.143162,"epoch_dec_deg":-35.472896,"epoch_moved_arcsec":0.536,"pm_ra_mas_yr":12.8,"pm_dec_mas_yr":-15.51,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Sagittarius","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-166136","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"18108-3529","companions":[{"measured":2024,"magnitude":9.87,"components":null,"discoverer_code":"B  1352","separation_arcsec":0.2,"position_angle_deg":230}],"spectral_type":"G3V","uncertainties":{"metallicity_fe_h":[0.07,0.07]},"color_index_bv":0.676,"luminosity_solar":2.2824433121735033,"metallicity_fe_h":0.01,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1982MSS...C03....0H, quality C)","surface_gravity_log_g":4.32,"surface_temperature_k":5648,"metallicity_fe_h_source":"One spectroscopic determination, compiled from the literature (PASTEL, Soubiran+ 2016)","proper_motion_ra_mas_yr":12.8,"proper_motion_dec_mas_yr":-15.51,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"HD","designation":"HD 166136"},{"catalog":"HIP","designation":"HIP 89076"}],"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."}