{"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":"2026-08-31T20:42:59.694Z","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":"aladfar","name":"Aladfar","class":"b6_blue_white_star","category":"star","object_type":"B6 blue-white star","mag":4.43,"mag_band":"V","abs_mag":-3.715,"abs_mag_band":"V","distance_ly":1387.8994310692349,"distance_method":"parallax","ra_deg":288.43953,"dec_deg":39.145968,"epoch_ra_deg":288.667456,"epoch_dec_deg":39.191319,"epoch_moved_arcsec":0.045,"pm_ra_mas_yr":-1.59,"pm_dec_mas_yr":-0.61,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Lyra","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/aladfar","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"19138+3909","companions":[{"measured":2017,"magnitude":8.58,"components":"AB","discoverer_code":"STF2487","separation_arcsec":28.4,"position_angle_deg":81},{"measured":2014,"magnitude":11.42,"components":"AC","discoverer_code":"STF2487","separation_arcsec":161.5,"position_angle_deg":151}],"radius_solar":8.75,"spectral_type":"B6","color_index_bv":-0.15,"luminosity_solar":2666.8586645214805,"metallicity_fe_h":-0.01,"radial_velocity_km_s":-8,"spectral_type_source":"SIMBAD (2023ApJS..264...17Z, quality E)","surface_gravity_log_g":3.299,"surface_temperature_k":14083,"metallicity_fe_h_source":"One spectroscopic determination, compiled from the literature (PASTEL, Soubiran+ 2016)","proper_motion_ra_mas_yr":-1.59,"proper_motion_dec_mas_yr":-0.61,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: above 7,500 K GSP-Phot's temperature and extinction are degenerate"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"20 Eta Lyr"},{"catalog":"Common name","designation":"Aladfar"},{"catalog":"HD","designation":"HD 180163"},{"catalog":"HIP","designation":"HIP 94481"},{"catalog":"HR","designation":"HR 7298"}],"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."}