{"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":"2026-09-02T19:20:27.906Z","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-172425","name":"HD 172425","class":"a2vn_white_main_sequence_star","category":"star","object_type":"A2Vn white main-sequence star","mag":8.74,"mag_band":"V","abs_mag":2.667,"abs_mag_band":"V","distance_ly":534.682500871677,"distance_method":"parallax","ra_deg":280.02097499999996,"dec_deg":3.356673,"epoch_ra_deg":280.356366,"epoch_dec_deg":3.380811,"epoch_moved_arcsec":0.234,"pm_ra_mas_yr":7.14,"pm_dec_mas_yr":-5.09,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Serpens","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-172425","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"18401+0321","age_years":301766250,"companions":[{"measured":2015,"magnitude":10.01,"components":null,"discoverer_code":"AG  224","separation_arcsec":22.1,"position_angle_deg":348}],"mass_solar":2.256,"radius_solar":1.983,"spectral_type":"A2Vn","color_index_bv":0.163,"luminosity_solar":7.467925899308832,"variable_mag_max":8.661,"variable_mag_min":8.791,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (2020AJ....160...52M, quality C)","surface_gravity_log_g":4.133,"surface_temperature_k":9654,"proper_motion_ra_mas_yr":7.14,"proper_motion_dec_mas_yr":-5.09,"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","bolometric_luminosity_solar":31.0316},"designations":[{"catalog":"HD","designation":"HD 172425"},{"catalog":"HIP","designation":"HIP 91538"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-02T18:38:07.546Z","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."}