{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.671","julian_year":2026.671,"time":"2026-09-03T01:10:02.286Z","years_from_j2000":26.671,"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-21020","name":"HD 21020","class":"f3v_yellow_white_main_sequence_star","category":"star","object_type":"F3V yellow-white main-sequence star","mag":7.57,"mag_band":"V","abs_mag":2.795,"abs_mag_band":"V","distance_ly":294.09944582009786,"distance_method":"parallax","ra_deg":50.817195,"dec_deg":-11.347055,"epoch_ra_deg":51.139104,"epoch_dec_deg":-11.251104,"epoch_moved_arcsec":2.803,"pm_ra_mas_yr":104.89,"pm_dec_mas_yr":6.61,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Eridanus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-21020","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"03233-1121","age_years":2147999800,"companions":[{"measured":2015,"magnitude":12.2,"components":null,"discoverer_code":"HJ 2187","separation_arcsec":62.7,"position_angle_deg":241}],"mass_solar":1.517,"radius_solar":2.196,"spectral_type":"F3V","color_index_bv":0.45,"luminosity_solar":6.637430704019088,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1999MSS...C05....0H, quality C)","surface_gravity_log_g":3.918,"surface_temperature_k":6444,"proper_motion_ra_mas_yr":104.89,"proper_motion_dec_mas_yr":6.61,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":7.6018},"designations":[{"catalog":"HD","designation":"HD 21020"},{"catalog":"HIP","designation":"HIP 15772"}],"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."}