{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.669","julian_year":2026.669,"time":"2026-09-02T07:12:04.706Z","years_from_j2000":26.669,"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-219917","name":"HD 219917","class":"a2_white_star","category":"star","object_type":"A2 white star","mag":7.24,"mag_band":"V","abs_mag":1.761,"abs_mag_band":"V","distance_ly":406.6788427165862,"distance_method":"parallax","ra_deg":349.78206,"dec_deg":48.919436,"epoch_ra_deg":350.094292,"epoch_dec_deg":49.066257,"epoch_moved_arcsec":2.073,"pm_ra_mas_yr":77.4,"pm_dec_mas_yr":7.06,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Andromeda","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-219917","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"23191+4855","age_years":1120985300,"companions":[{"measured":2016,"magnitude":11.2,"components":"Aa,Ab","discoverer_code":"HDS3321","separation_arcsec":0.5,"position_angle_deg":94},{"measured":2015,"magnitude":8.62,"components":"AB","discoverer_code":"ES 2725","separation_arcsec":54.5,"position_angle_deg":235}],"mass_solar":1.777,"radius_solar":2.208,"spectral_type":"A2","color_index_bv":0.276,"luminosity_solar":17.202834055304336,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1993yCat.3135....0C, quality E)","surface_gravity_log_g":3.814,"surface_temperature_k":7598,"proper_motion_ra_mas_yr":77.4,"proper_motion_dec_mas_yr":7.06,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: above 7,500 K GSP-Phot's temperature and extinction are degenerate","bolometric_luminosity_solar":14.088},"designations":[{"catalog":"HD","designation":"HD 219917"},{"catalog":"HIP","designation":"HIP 115128"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-01T22:58:55.274Z","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."}