{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.684","julian_year":2026.684,"time":"2026-09-07T18:17:17.924Z","years_from_j2000":26.684,"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-147749","name":"20 ν¹ CrB","class":"m2iii_red_giant","category":"star","object_type":"M2III red giant","mag":5.2,"mag_band":"V","abs_mag":-1.266,"abs_mag_band":"V","distance_ly":640.7788874482897,"distance_method":"parallax","ra_deg":245.58927,"dec_deg":33.799052,"epoch_ra_deg":245.843055,"epoch_dec_deg":33.73515,"epoch_moved_arcsec":1.031,"pm_ra_mas_yr":5.52,"pm_dec_mas_yr":-38.25,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Corona Borealis","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-147749","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"16224+3348","companions":[{"measured":2023,"magnitude":14,"components":"AE","discoverer_code":"SMR  92","separation_arcsec":11.8,"position_angle_deg":65},{"measured":2023,"magnitude":12.62,"components":"AC","discoverer_code":"H N  81","separation_arcsec":68.4,"position_angle_deg":241},{"measured":2020,"magnitude":11.53,"components":"AD","discoverer_code":"STFA 29","separation_arcsec":277.2,"position_angle_deg":153},{"measured":2016,"magnitude":5.58,"components":"AB","discoverer_code":"STFA 29","separation_arcsec":356.1,"position_angle_deg":164}],"spectral_type":"M2III","color_index_bv":1.631,"luminosity_solar":279.51170539918456,"radial_velocity_km_s":-13,"spectral_type_source":"SIMBAD (quality D)","proper_motion_ra_mas_yr":5.52,"proper_motion_dec_mas_yr":-38.25},"designations":[{"catalog":"Bayer/Flamsteed","designation":"20 Nu1 CrB"},{"catalog":"HD","designation":"HD 147749"},{"catalog":"HIP","designation":"HIP 80197"},{"catalog":"HR","designation":"HR 6107"}],"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."}