{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.665","julian_year":2026.665,"time":"2026-08-31T18:24:26.466Z","years_from_j2000":26.665,"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":"arneb","name":"Arneb","class":"f0ib_yellow_white_supergiant","category":"star","object_type":"F0Ib yellow-white supergiant","mag":2.58,"mag_band":"V","abs_mag":-6.583,"abs_mag_band":"V","distance_ly":2218.7508399776225,"distance_method":"parallax","ra_deg":83.18256000000001,"dec_deg":-17.822289,"epoch_ra_deg":83.478947,"epoch_dec_deg":-17.802614,"epoch_moved_arcsec":0.096,"pm_ra_mas_yr":3.27,"pm_dec_mas_yr":1.54,"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/arneb","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"05327-1749","companions":[{"measured":2015,"magnitude":11.2,"components":"AB","discoverer_code":"HJ 3766","separation_arcsec":35.4,"position_angle_deg":157},{"measured":2015,"magnitude":11.9,"components":"AC","discoverer_code":"HJ 3766","separation_arcsec":90.8,"position_angle_deg":186}],"spectral_type":"F0Ib","uncertainties":{"metallicity_fe_h":[0.061,0.061]},"color_index_bv":0.211,"luminosity_solar":37428.29122408052,"metallicity_fe_h":0.01,"radial_velocity_km_s":24,"spectral_type_source":"SIMBAD (2001AJ....121.2148G, quality C)","surface_gravity_log_g":1.52,"surface_temperature_k":7297,"metallicity_fe_h_source":"Median of 7 spectroscopic determinations in 7 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":3.27,"proper_motion_dec_mas_yr":1.54,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"11 Alpha Lep"},{"catalog":"Common name","designation":"Arneb"},{"catalog":"HD","designation":"HD 36673"},{"catalog":"HIP","designation":"HIP 25985"},{"catalog":"HR","designation":"HR 1865"}],"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."}