{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.678","julian_year":2026.678,"time":"2026-09-05T13:00:08.341Z","years_from_j2000":26.678,"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-206644","name":"77 Cyg","class":"a0v_a0v_white_main_sequence_star","category":"star","object_type":"A0V+A0V white main-sequence star","mag":5.73,"mag_band":"V","abs_mag":0.221,"abs_mag_band":"V","distance_ly":412.33439430619455,"distance_method":"parallax","ra_deg":325.59564,"dec_deg":41.077019,"epoch_ra_deg":325.86482,"epoch_dec_deg":41.199294,"epoch_moved_arcsec":0.625,"pm_ra_mas_yr":23.38,"pm_dec_mas_yr":-1.6,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Cygnus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-206644","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"21424+4105","companions":[{"measured":2015,"magnitude":6.72,"components":"AB","discoverer_code":"KUI 108","separation_arcsec":0.2,"position_angle_deg":9},{"measured":2017,"magnitude":7.8,"components":"AB,C","discoverer_code":"ARY 129","separation_arcsec":145.5,"position_angle_deg":132}],"spectral_type":"A0V+A0V","color_index_bv":0.055,"luminosity_solar":71.05587633694735,"radial_velocity_km_s":-25,"spectral_type_source":"SIMBAD (1995ApJS...99..135A, quality C)","proper_motion_ra_mas_yr":23.38,"proper_motion_dec_mas_yr":-1.6},"designations":[{"catalog":"Bayer/Flamsteed","designation":"77 Cyg"},{"catalog":"HD","designation":"HD 206644"},{"catalog":"HIP","designation":"HIP 107162"},{"catalog":"HR","designation":"HR 8300"}],"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."}