{"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":"2026-09-04T09:08:56.861Z","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-190771","name":"HD 190771","class":"g2v_yellow_main_sequence_star","category":"star","object_type":"G2V yellow main-sequence star","mag":6.18,"mag_band":"V","abs_mag":4.81,"abs_mag_band":"V","distance_ly":61.28445721659837,"distance_method":"parallax","ra_deg":301.29058499999996,"dec_deg":38.478457,"epoch_ra_deg":301.534664,"epoch_dec_deg":38.555255,"epoch_moved_arcsec":7.629,"pm_ra_mas_yr":263.35,"pm_dec_mas_yr":111.57,"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-190771","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"20052+3829","age_years":9188884000,"companions":[{"measured":2015,"magnitude":13.2,"components":"AB","discoverer_code":"BU 1481","separation_arcsec":42.7,"position_angle_deg":240},{"measured":2015,"magnitude":12.22,"components":"AC","discoverer_code":"WAL 126","separation_arcsec":70.4,"position_angle_deg":212}],"mass_solar":0.946,"radius_solar":1.06,"spectral_type":"G2V","uncertainties":{"metallicity_fe_h":[0.032,0.032]},"color_index_bv":0.654,"luminosity_solar":1.0375284158180118,"metallicity_fe_h":0.13,"radial_velocity_km_s":-22.5,"spectral_type_source":"SIMBAD (2003AJ....126.2048G, quality C)","surface_gravity_log_g":4.344,"surface_temperature_k":5680,"metallicity_fe_h_source":"Median of 9 spectroscopic determinations in 10 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":263.35,"proper_motion_dec_mas_yr":111.57,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":1.0431},"designations":[{"catalog":"Gliese","designation":"GJ 1249"},{"catalog":"HD","designation":"HD 190771"},{"catalog":"HIP","designation":"HIP 98921"},{"catalog":"HR","designation":"HR 7683"}],"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."}