{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.680","julian_year":2026.68,"time":"2026-09-06T09:32:45.588Z","years_from_j2000":26.68,"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-100493","name":"HD 100493","class":"a2iv_v_white_subgiant","category":"star","object_type":"A2IV/V white subgiant","mag":5.39,"mag_band":"V","abs_mag":0.027,"abs_mag_band":"V","distance_ly":385.5276016216554,"distance_method":"parallax","ra_deg":173.405055,"dec_deg":-40.586637,"epoch_ra_deg":173.732094,"epoch_dec_deg":-40.734794,"epoch_moved_arcsec":2.346,"pm_ra_mas_yr":-83.64,"pm_dec_mas_yr":27.08,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Centaurus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-100493","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"11336-4035","companions":[{"measured":2022,"magnitude":6.16,"components":null,"discoverer_code":"I    78","separation_arcsec":0.5,"position_angle_deg":104}],"spectral_type":"A2IV/V","color_index_bv":0.117,"luminosity_solar":84.95716271561207,"radial_velocity_km_s":9,"spectral_type_source":"SIMBAD (1978MSS...C02....0H, quality D)","proper_motion_ra_mas_yr":-83.64,"proper_motion_dec_mas_yr":27.08},"designations":[{"catalog":"HD","designation":"HD 100493"},{"catalog":"HIP","designation":"HIP 56391"},{"catalog":"HR","designation":"HR 4453"}],"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."}