{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.670","julian_year":2026.67,"time":"2026-09-02T21:23:16.489Z","years_from_j2000":26.67,"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-22255","name":"HD 22255","class":"f5_yellow_white_star","category":"star","object_type":"F5 yellow-white star","mag":7.48,"mag_band":"V","abs_mag":3.597,"abs_mag_band":"V","distance_ly":194.95312549625132,"distance_method":"parallax","ra_deg":53.792325000000005,"dec_deg":5.714011,"epoch_ra_deg":54.148461,"epoch_dec_deg":5.803539,"epoch_moved_arcsec":0.948,"pm_ra_mas_yr":7.55,"pm_dec_mas_yr":-34.75,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Taurus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-22255","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"03352+0543","age_years":3600947000,"companions":[{"measured":2016,"magnitude":14.5,"components":"AC","discoverer_code":"KPP4353","separation_arcsec":4.3,"position_angle_deg":251},{"measured":2016,"magnitude":12.3,"components":"AB","discoverer_code":"TOK 657","separation_arcsec":141.1,"position_angle_deg":73}],"mass_solar":1.243,"radius_solar":1.547,"spectral_type":"F5","uncertainties":{"metallicity_fe_h":[0.085,0.085]},"color_index_bv":0.515,"luminosity_solar":3.171027438947892,"metallicity_fe_h":-0.31,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1993yCat.3135....0C, quality E)","surface_gravity_log_g":4.037,"surface_temperature_k":6210,"metallicity_fe_h_source":"Median of 3 spectroscopic determinations in 5 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":7.55,"proper_motion_dec_mas_yr":-34.75,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":3.2031},"designations":[{"catalog":"HD","designation":"HD 22255"},{"catalog":"HIP","designation":"HIP 16723"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-02T19:50:56.720Z","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."}