{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.667","julian_year":2026.667,"time":"2026-09-01T16:46:18.406Z","years_from_j2000":26.667,"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-99151","name":"HD 99151","class":"g5v_yellow_main_sequence_star","category":"star","object_type":"G5V yellow main-sequence star","mag":9.36,"mag_band":"V","abs_mag":4.571,"abs_mag_band":"V","distance_ly":295.96766955165936,"distance_method":"parallax","ra_deg":171.05601000000001,"dec_deg":-47.976146,"epoch_ra_deg":171.371816,"epoch_dec_deg":-48.124433,"epoch_moved_arcsec":3.399,"pm_ra_mas_yr":-21.49,"pm_dec_mas_yr":-125.63,"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-99151","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"11242-4759","companions":[{"measured":2018,"magnitude":10.67,"components":null,"discoverer_code":"CPO  21","separation_arcsec":3.3,"position_angle_deg":281}],"spectral_type":"G5V","color_index_bv":0.676,"luminosity_solar":1.2930043917962792,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1978MSS...C02....0H, quality C)","proper_motion_ra_mas_yr":-21.49,"proper_motion_dec_mas_yr":-125.63},"designations":[{"catalog":"HD","designation":"HD 99151"},{"catalog":"HIP","designation":"HIP 55659"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-30T09:56:50.739Z","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."}