{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.674","julian_year":2026.674,"time":"2026-09-04T07:46:03.562Z","years_from_j2000":26.674,"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-170883","name":"HD 170883","class":"k3iii_orange_giant","category":"star","object_type":"K3III orange giant","mag":8.49,"mag_band":"V","abs_mag":-0.673,"abs_mag_band":"V","distance_ly":2218.7508399776225,"distance_method":"parallax","ra_deg":277.992255,"dec_deg":-6.114484,"epoch_ra_deg":278.352207,"epoch_dec_deg":-6.095498,"epoch_moved_arcsec":0.003,"pm_ra_mas_yr":-0.07,"pm_dec_mas_yr":0.11,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Scutum","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-170883","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"18320-0607","companions":[{"measured":1991,"magnitude":9.46,"components":null,"discoverer_code":"HDS2629","separation_arcsec":0.1,"position_angle_deg":149}],"spectral_type":"K3III","color_index_bv":1.5,"luminosity_solar":161.88253626421067,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1999MSS...C05....0H, quality C)","proper_motion_ra_mas_yr":-0.07,"proper_motion_dec_mas_yr":0.11},"designations":[{"catalog":"HD","designation":"HD 170883"},{"catalog":"HIP","designation":"HIP 90847"}],"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."}