{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.669","julian_year":2026.669,"time":"2026-09-02T12:11:43.165Z","years_from_j2000":26.669,"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-42729","name":"HD 42729","class":"b9_5iv_v_blue_white_subgiant","category":"star","object_type":"B9.5IV/V blue-white subgiant","mag":6.08,"mag_band":"V","abs_mag":-0.5,"abs_mag_band":"V","distance_ly":675.2718813301016,"distance_method":"parallax","ra_deg":92.806905,"dec_deg":-26.4821,"epoch_ra_deg":93.076487,"epoch_dec_deg":-26.487428,"epoch_moved_arcsec":0.146,"pm_ra_mas_yr":0.82,"pm_dec_mas_yr":5.42,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Lepus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-42729","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"spectral_type":"B9.5IV/V","color_index_bv":-0.021,"luminosity_solar":138.03842646028852,"radial_velocity_km_s":24,"spectral_type_source":"SIMBAD (1982MSS...C03....0H, quality D)","surface_temperature_k":9841,"proper_motion_ra_mas_yr":0.82,"proper_motion_dec_mas_yr":5.42,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"HD","designation":"HD 42729"},{"catalog":"HIP","designation":"HIP 29347"},{"catalog":"HR","designation":"HR 2206"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-01T22:58:55.274Z","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."}