{"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":"2026-09-01T19:39:22.390Z","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-22951","name":"40 Per","class":"b0_5v_blue_white_main_sequence_star","category":"star","object_type":"B0.5V blue-white main-sequence star","mag":4.97,"mag_band":"V","abs_mag":-2.58,"abs_mag_band":"V","distance_ly":1055.5222727603,"distance_method":"parallax","ra_deg":55.594364999999996,"dec_deg":33.965026,"epoch_ra_deg":56.020933,"epoch_dec_deg":34.050895,"epoch_moved_arcsec":0.182,"pm_ra_mas_yr":4.39,"pm_dec_mas_yr":-5.21,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Perseus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-22951","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"03424+3358","companions":[{"measured":2016,"magnitude":10.04,"components":null,"discoverer_code":"STF 431","separation_arcsec":19.9,"position_angle_deg":239}],"radius_solar":10.364,"spectral_type":"B0.5V","color_index_bv":-0.048,"luminosity_solar":937.5620069258802,"metallicity_fe_h":-0.43,"radial_velocity_km_s":20,"spectral_type_source":"SIMBAD (quality C)","surface_gravity_log_g":3.39,"surface_temperature_k":19605,"metallicity_fe_h_source":"One spectroscopic determination, compiled from the literature (PASTEL, Soubiran+ 2016)","proper_motion_ra_mas_yr":4.39,"proper_motion_dec_mas_yr":-5.21,"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; Gaia's classifier calls the source a binary, which GSP-Phot fitted as one star"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"40 Per"},{"catalog":"HD","designation":"HD 22951"},{"catalog":"HIP","designation":"HIP 17313"},{"catalog":"HR","designation":"HR 1123"}],"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."}