{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.679","julian_year":2026.679,"time":"2026-09-05T19:54:30.228Z","years_from_j2000":26.679,"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-177913","name":"HD 177913","class":"b8ii_iii_blue_white_bright_giant","category":"star","object_type":"B8II/III blue-white bright giant","mag":7.64,"mag_band":"V","abs_mag":-1.692,"abs_mag_band":"V","distance_ly":2398.208602124929,"distance_method":"parallax","ra_deg":286.82733,"dec_deg":-17.241874,"epoch_ra_deg":287.216018,"epoch_dec_deg":-17.200324,"epoch_moved_arcsec":0.14,"pm_ra_mas_yr":-1.38,"pm_dec_mas_yr":-5.07,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Sagittarius","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-177913","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"mass_solar":4.911,"radius_solar":12.55,"spectral_type":"B8II/III","color_index_bv":-0.025,"luminosity_solar":413.80906481672537,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1988MSS...C04....0H, quality D)","surface_gravity_log_g":2.696,"surface_temperature_k":8000,"proper_motion_ra_mas_yr":-1.38,"proper_motion_dec_mas_yr":-5.07,"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":1045.9503},"designations":[{"catalog":"HD","designation":"HD 177913"},{"catalog":"HIP","designation":"HIP 93906"}],"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."}