{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.669","julian_year":2026.669,"time":"2026-09-02T12:05:14.211Z","years_from_j2000":26.669,"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-21708","name":"HD 21708","class":"b9_blue_white_star","category":"star","object_type":"B9 blue-white star","mag":8.17,"mag_band":"V","abs_mag":-1.584,"abs_mag_band":"V","distance_ly":2912.110375546761,"distance_method":"parallax","ra_deg":53.445750000000004,"dec_deg":63.440995,"epoch_ra_deg":54.028752,"epoch_dec_deg":63.531188,"epoch_moved_arcsec":0.362,"pm_ra_mas_yr":8.5,"pm_dec_mas_yr":-10.56,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Camelopardalis","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-21708","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"spectral_type":"B9","color_index_bv":0.165,"luminosity_solar":374.6277983440598,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1993yCat.3135....0C, quality E)","proper_motion_ra_mas_yr":8.5,"proper_motion_dec_mas_yr":-10.56},"designations":[{"catalog":"HD","designation":"HD 21708"},{"catalog":"HIP","designation":"HIP 16610"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-01T22:58:55.274Z","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."}