{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.668","julian_year":2026.668,"time":"2026-09-01T20:10:50.470Z","years_from_j2000":26.668,"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-55489","name":"HD 55489","class":"a_5_v_f_k_iii_white_star","category":"star","object_type":"A(5)V+(F/K)(III) white star","mag":7.54,"mag_band":"V","abs_mag":-1.683,"abs_mag_band":"V","distance_ly":2280.8138324678307,"distance_method":"parallax","ra_deg":108.205725,"dec_deg":-7.149378,"epoch_ra_deg":108.531762,"epoch_dec_deg":-7.194281,"epoch_moved_arcsec":0.053,"pm_ra_mas_yr":-1.94,"pm_dec_mas_yr":0.45,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Monoceros","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-55489","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"07128-0709","companions":[{"measured":2021,"magnitude":9.34,"components":"AB","discoverer_code":"BU  197","separation_arcsec":2.2,"position_angle_deg":147},{"measured":2015,"magnitude":11.5,"components":"AC","discoverer_code":"LV   18","separation_arcsec":20.1,"position_angle_deg":21},{"measured":2015,"magnitude":12.01,"components":"AD","discoverer_code":"LV   18","separation_arcsec":38.8,"position_angle_deg":186}],"spectral_type":"A(5)V+(F/K)(III)","color_index_bv":0.455,"luminosity_solar":410.39305246101617,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1999MSS...C05....0H, quality E)","surface_temperature_k":6809,"proper_motion_ra_mas_yr":-1.94,"proper_motion_dec_mas_yr":0.45,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"HD","designation":"HD 55489"},{"catalog":"HIP","designation":"HIP 34862"}],"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."}