{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.654","julian_year":2026.654,"time":"2026-08-27T22:30:11.322Z","years_from_j2000":26.654,"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":"hip-17641","name":"HIP 17641","class":"f8_yellow_white_star","category":"star","object_type":"F8 yellow-white star","mag":10.92,"mag_band":"V","abs_mag":2.719,"abs_mag_band":"V","distance_ly":1424.2635840900077,"distance_method":"parallax","ra_deg":56.70247500000001,"dec_deg":0.988149,"epoch_ra_deg":57.049043,"epoch_dec_deg":1.072052,"epoch_moved_arcsec":1.781,"pm_ra_mas_yr":53.13,"pm_dec_mas_yr":40.52,"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/hip-17641","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"age_years":1816476200,"mass_solar":1.142,"radius_solar":1.131,"spectral_type":"F8","uncertainties":{"metallicity_fe_h":[0.11,0.11]},"color_index_bv":0.584,"luminosity_solar":7.118688672622804,"metallicity_fe_h":0,"variable_mag_max":10.85,"variable_mag_min":10.98,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (quality D)","surface_gravity_log_g":4.26,"surface_temperature_k":6151,"metallicity_fe_h_source":"One spectroscopic determination, compiled from the literature (PASTEL, Soubiran+ 2016)","proper_motion_ra_mas_yr":53.13,"proper_motion_dec_mas_yr":40.52,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":1.6469},"designations":[{"catalog":"HIP","designation":"HIP 17641"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-27T19:16:43.430Z","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."}