{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.676","julian_year":2026.676,"time":"2026-09-04T19:38:59.661Z","years_from_j2000":26.676,"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-176318","name":"HD 176318","class":"b7iv_blue_white_subgiant","category":"star","object_type":"B7IV blue-white subgiant","mag":5.89,"mag_band":"V","abs_mag":-0.354,"abs_mag_band":"V","distance_ly":578.291565510672,"distance_method":"parallax","ra_deg":284.50791,"dec_deg":38.266188,"epoch_ra_deg":284.737327,"epoch_dec_deg":38.301735,"epoch_moved_arcsec":0.151,"pm_ra_mas_yr":-5.25,"pm_dec_mas_yr":2.13,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Lyra","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-176318","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"18581+3813","companions":[{"measured":2014,"magnitude":14.6,"components":"EG","discoverer_code":"FYM  27","separation_arcsec":33.2,"position_angle_deg":206},{"measured":2014,"magnitude":16,"components":"EI","discoverer_code":"FYM  27","separation_arcsec":44.7,"position_angle_deg":38},{"measured":2014,"magnitude":13.7,"components":"EH","discoverer_code":"FYM  27","separation_arcsec":72.8,"position_angle_deg":222},{"measured":2014,"magnitude":11.26,"components":"EF","discoverer_code":"SMR  14","separation_arcsec":82.7,"position_angle_deg":331}],"mass_solar":3.705,"radius_solar":4.142,"spectral_type":"B7IV","color_index_bv":-0.09,"luminosity_solar":120.6701909593275,"radial_velocity_km_s":-28,"spectral_type_source":"SIMBAD (quality C)","surface_gravity_log_g":3.791,"surface_temperature_k":11922,"proper_motion_ra_mas_yr":-5.25,"proper_motion_dec_mas_yr":2.13,"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":300.0069},"designations":[{"catalog":"HD","designation":"HD 176318"},{"catalog":"HIP","designation":"HIP 93104"},{"catalog":"HR","designation":"HR 7174"}],"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."}