{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.673","julian_year":2026.673,"time":"2026-09-03T15:14:13.077Z","years_from_j2000":26.673,"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-100920","name":"91 υ Leo","class":"g9iiibfe_0_5_yellow_giant","category":"star","object_type":"G9IIIbFe-0.5 yellow giant","mag":4.3,"mag_band":"V","abs_mag":0.573,"abs_mag_band":"V","distance_ly":181.50047954094651,"distance_method":"parallax","ra_deg":174.23721,"dec_deg":-0.823749,"epoch_ra_deg":174.581012,"epoch_dec_deg":-0.971985,"epoch_moved_arcsec":1.159,"pm_ra_mas_yr":1.3,"pm_dec_mas_yr":43.43,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Leo","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-100920","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"spectral_type":"G9IIIbFe-0.5","color_index_bv":0.983,"luminosity_solar":51.38069802323445,"radial_velocity_km_s":1,"spectral_type_source":"SIMBAD (1989ApJS...71..245K, quality B)","proper_motion_ra_mas_yr":1.3,"proper_motion_dec_mas_yr":43.43},"designations":[{"catalog":"Bayer/Flamsteed","designation":"91 Upsilon Leo"},{"catalog":"Exoplanet host","designation":"υ Leo"},{"catalog":"HD","designation":"HD 100920"},{"catalog":"HIP","designation":"HIP 56647"},{"catalog":"HR","designation":"HR 4471"}],"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."}