{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.668","julian_year":2026.668,"time":"2026-09-01T21:11:10.429Z","years_from_j2000":26.668,"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-200370","name":"HD 200370","class":"f0_yellow_white_star","category":"star","object_type":"F0 yellow-white star","mag":7.46,"mag_band":"V","abs_mag":0.476,"abs_mag_band":"V","distance_ly":813.3576854331724,"distance_method":"parallax","ra_deg":315.458625,"dec_deg":39.260614,"epoch_ra_deg":315.715484,"epoch_dec_deg":39.365625,"epoch_moved_arcsec":0.607,"pm_ra_mas_yr":-13.41,"pm_dec_mas_yr":-18.41,"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-200370","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"21018+3916","age_years":1469971700,"companions":[{"measured":2023,"magnitude":8.71,"components":null,"discoverer_code":"STF2746","separation_arcsec":1.3,"position_angle_deg":323}],"mass_solar":1.821,"radius_solar":3.599,"spectral_type":"F0","color_index_bv":0.402,"luminosity_solar":56.182362813422785,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1993yCat.3135....0C, quality E)","surface_gravity_log_g":3.422,"surface_temperature_k":6337,"proper_motion_ra_mas_yr":-13.41,"proper_motion_dec_mas_yr":-18.41,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":17.3793},"designations":[{"catalog":"HD","designation":"HD 200370"},{"catalog":"HIP","designation":"HIP 103782"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-30T09:56:50.739Z","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."}