{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.675","julian_year":2026.675,"time":"2026-09-04T14:14:08.404Z","years_from_j2000":26.675,"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-191833","name":"HD 191833","class":"f7v_yellow_white_main_sequence_star","category":"star","object_type":"F7V yellow-white main-sequence star","mag":8.33,"mag_band":"V","abs_mag":2.158,"abs_mag_band":"V","distance_ly":559.4449453806876,"distance_method":"parallax","ra_deg":302.6535,"dec_deg":34.867702,"epoch_ra_deg":302.909259,"epoch_dec_deg":34.946498,"epoch_moved_arcsec":1.084,"pm_ra_mas_yr":25.97,"pm_dec_mas_yr":-31.24,"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-191833","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"20106+3452","age_years":4908129700,"companions":[{"measured":2018,"magnitude":9.45,"components":"AB","discoverer_code":"A   281","separation_arcsec":4.2,"position_angle_deg":172},{"measured":2015,"magnitude":9.78,"components":"AC","discoverer_code":"ARN  96","separation_arcsec":63.6,"position_angle_deg":314}],"mass_solar":1.223,"radius_solar":1.93,"spectral_type":"F7V","color_index_bv":0.626,"luminosity_solar":11.934383792107955,"radial_velocity_km_s":34,"spectral_type_source":"SIMBAD (1958JO.....41...43D, quality C)","surface_gravity_log_g":4.038,"surface_temperature_k":5997,"proper_motion_ra_mas_yr":25.97,"proper_motion_dec_mas_yr":-31.24,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":4.3532},"designations":[{"catalog":"HD","designation":"HD 191833"},{"catalog":"HIP","designation":"HIP 99411"}],"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."}