{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.679","julian_year":2026.679,"time":"2026-09-06T01:30:54.619Z","years_from_j2000":26.679,"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-261309","name":"HD 261309","class":"g5_yellow_star","category":"star","object_type":"G5 yellow star","mag":10.28,"mag_band":"V","abs_mag":4.878,"abs_mag_band":"V","distance_ly":392.4864740966198,"distance_method":"parallax","ra_deg":100.040475,"dec_deg":33.707492,"epoch_ra_deg":100.483067,"epoch_dec_deg":33.683051,"epoch_moved_arcsec":0.195,"pm_ra_mas_yr":1.59,"pm_dec_mas_yr":-7.12,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Auriga","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-261309","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"06402+3342","companions":[{"measured":2015,"magnitude":14.96,"components":"BC","discoverer_code":"SIN  22","separation_arcsec":69.8,"position_angle_deg":296},{"measured":2015,"magnitude":12.27,"components":"BD","discoverer_code":"SIN  22","separation_arcsec":134.1,"position_angle_deg":281},{"measured":2015,"magnitude":14.66,"components":"BE","discoverer_code":"SIN  22","separation_arcsec":142.5,"position_angle_deg":65},{"measured":2015,"magnitude":13.35,"components":"BF","discoverer_code":"SIN  22","separation_arcsec":196.1,"position_angle_deg":301},{"measured":2015,"magnitude":13.93,"components":"BG","discoverer_code":"SIN  22","separation_arcsec":205.1,"position_angle_deg":275}],"spectral_type":"G5","color_index_bv":0.421,"luminosity_solar":0.974540741766306,"variable_mag_max":10.183,"variable_mag_min":10.343,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (quality D)","proper_motion_ra_mas_yr":1.59,"proper_motion_dec_mas_yr":-7.12},"designations":[{"catalog":"HD","designation":"HD 261309"},{"catalog":"HIP","designation":"HIP 31913"}],"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."}