{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.665","julian_year":2026.665,"time":"2026-08-31T20:08:44.578Z","years_from_j2000":26.665,"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":"pollux","name":"Pollux","class":"k0iiib_orange_giant","category":"star","object_type":"K0IIIb orange giant","mag":1.16,"mag_band":"V","abs_mag":1.084,"abs_mag_band":"V","distance_ly":33.78458222941115,"distance_method":"parallax","ra_deg":116.329155,"dec_deg":28.026199,"epoch_ra_deg":116.739507,"epoch_dec_deg":27.961174,"epoch_moved_arcsec":16.729,"pm_ra_mas_yr":-625.69,"pm_dec_mas_yr":-45.95,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Gemini","discovered":"Antiquity","featured":true,"url":"https://spacecatalog.org/object/pollux","radius_km":null,"radius_kind":null,"data_quality":null,"description":"The nearest giant star to the Sun, and the first such star found to host a planet.","properties":{"wds_id":"07453+2802","companions":[{"measured":2009,"magnitude":13.7,"components":"AB","discoverer_code":"BU  580","separation_arcsec":39.8,"position_angle_deg":76},{"measured":2013,"magnitude":11.34,"components":"AG","discoverer_code":"BU  580","separation_arcsec":152.2,"position_angle_deg":353},{"measured":2013,"magnitude":10.95,"components":"AC","discoverer_code":"H 6  42","separation_arcsec":257.5,"position_angle_deg":76},{"measured":2013,"magnitude":11.6,"components":"AE","discoverer_code":"BU  580","separation_arcsec":289.9,"position_angle_deg":90},{"measured":2013,"magnitude":10.51,"components":"AF","discoverer_code":"STFB  5","separation_arcsec":313.5,"position_angle_deg":79}],"wikidata_id":"Q13028","also_known_as":["Beta Gem","Beta Geminorum","β Gem","β Geminorum"],"spectral_type":"K0IIIb","uncertainties":{"metallicity_fe_h":[0.159,0.159]},"color_index_bv":0.991,"luminosity_solar":32.09223768048434,"metallicity_fe_h":0.07,"wikipedia_article":"Pollux (star)","radial_velocity_km_s":3.6,"spectral_type_source":"SIMBAD (1989ApJS...71..245K, quality B)","surface_gravity_log_g":2.92,"surface_temperature_k":4856,"metallicity_fe_h_source":"Median of 26 spectroscopic determinations in 30 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":-625.69,"proper_motion_dec_mas_yr":-45.95,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"78 Beta Gem"},{"catalog":"Common name","designation":"Pollux"},{"catalog":"Gliese","designation":"GJ 286"},{"catalog":"Gliese","designation":"Gl 286"},{"catalog":"HD","designation":"HD 62509"},{"catalog":"HIP","designation":"HIP 37826"},{"catalog":"HR","designation":"HR 2990"},{"catalog":"IRAS","designation":"IRAS 07422+2808"}],"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."}