{"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":"2026-08-31T20:21:23.603Z","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":"alshat","name":"Alshat","class":"b9iv_blue_white_subgiant","category":"star","object_type":"B9IV blue-white subgiant","mag":4.77,"mag_band":"V","abs_mag":0.32,"abs_mag_band":"V","distance_ly":253.22715934652413,"distance_method":"parallax","ra_deg":305.165895,"dec_deg":-12.75908,"epoch_ra_deg":305.537799,"epoch_dec_deg":-12.674607,"epoch_moved_arcsec":0.572,"pm_ra_mas_yr":15.71,"pm_dec_mas_yr":-14.63,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Capricornus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/alshat","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"20207-1246","companions":[{"measured":2012,"magnitude":11.8,"components":null,"discoverer_code":"LAM   5","separation_arcsec":53.2,"position_angle_deg":211}],"spectral_type":"B9IV","uncertainties":{"metallicity_fe_h":[0.197,0.197]},"color_index_bv":-0.047,"luminosity_solar":64.86344335482381,"metallicity_fe_h":-0.05,"radial_velocity_km_s":-2,"spectral_type_source":"SIMBAD (1988MSS...C04....0H, quality C)","surface_gravity_log_g":3.77,"surface_temperature_k":10286,"metallicity_fe_h_source":"Median of 12 spectroscopic determinations in 13 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":15.71,"proper_motion_dec_mas_yr":-14.63,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"8 Nu Cap"},{"catalog":"Common name","designation":"Alshat"},{"catalog":"HD","designation":"HD 193432"},{"catalog":"HIP","designation":"HIP 100310"},{"catalog":"HR","designation":"HR 7773"}],"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."}