{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.670","julian_year":2026.67,"time":"2026-09-02T19:12:04.340Z","years_from_j2000":26.67,"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-75737","name":"15 Hya","class":"a2_3v_white_main_sequence_star","category":"star","object_type":"A2/3V white main-sequence star","mag":5.55,"mag_band":"V","abs_mag":-0.13,"abs_mag_band":"V","distance_ly":446.17833699635014,"distance_method":"parallax","ra_deg":132.89338500000002,"dec_deg":-7.177226,"epoch_ra_deg":133.222992,"epoch_dec_deg":-7.277638,"epoch_moved_arcsec":1.309,"pm_ra_mas_yr":-48.79,"pm_dec_mas_yr":-5.34,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Hydra","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-75737","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"08516-0711","companions":[{"measured":2021,"magnitude":7.41,"components":"AB","discoverer_code":"BU  587","separation_arcsec":1.2,"position_angle_deg":118},{"measured":2015,"magnitude":11.41,"components":"AB,C","discoverer_code":"H 5 120","separation_arcsec":45.6,"position_angle_deg":6},{"measured":2015,"magnitude":12.1,"components":"AB,D","discoverer_code":"BU  587","separation_arcsec":55.5,"position_angle_deg":56}],"spectral_type":"A2/3V","color_index_bv":0.15,"luminosity_solar":98.17479430199843,"radial_velocity_km_s":37,"spectral_type_source":"SIMBAD (1999MSS...C05....0H, quality D)","proper_motion_ra_mas_yr":-48.79,"proper_motion_dec_mas_yr":-5.34},"designations":[{"catalog":"Bayer/Flamsteed","designation":"15 Hya"},{"catalog":"HD","designation":"HD 75737"},{"catalog":"HIP","designation":"HIP 43496"},{"catalog":"HR","designation":"HR 3523"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-02T18:38:07.546Z","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."}