{"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":"2026-09-04T20:41:09.176Z","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-172883","name":"HD 172883","class":"b9iii_blue_white_giant","category":"star","object_type":"B9III: blue-white giant","mag":6,"mag_band":"V","abs_mag":-0.095,"abs_mag_band":"V","distance_ly":539.9939574827943,"distance_method":"parallax","ra_deg":279.97005,"dec_deg":52.196075,"epoch_ra_deg":280.123859,"epoch_dec_deg":52.220065,"epoch_moved_arcsec":0.589,"pm_ra_mas_yr":5.44,"pm_dec_mas_yr":21.39,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Draco","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-172883","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"spectral_type":"B9III:","color_index_bv":-0.067,"luminosity_solar":95.0604793656281,"radial_velocity_km_s":-18,"spectral_type_source":"SIMBAD (1970MmRAS..72..233H, quality D)","proper_motion_ra_mas_yr":5.44,"proper_motion_dec_mas_yr":21.39},"designations":[{"catalog":"HD","designation":"HD 172883"},{"catalog":"HIP","designation":"HIP 91525"},{"catalog":"HR","designation":"HR 7028"}],"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."}