{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.677","julian_year":2026.677,"time":"2026-09-05T03:26:33.837Z","years_from_j2000":26.677,"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-225180","name":"9 Cas","class":"a1ii_iii_white_bright_giant","category":"star","object_type":"A1II-III white bright giant","mag":5.9,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":1.05693,"dec_deg":62.287664,"epoch_ra_deg":1.402807,"epoch_dec_deg":62.437202,"epoch_moved_arcsec":0.028,"pm_ra_mas_yr":-0.99,"pm_dec_mas_yr":-0.37,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Cassiopeia","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-225180","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"00042+6217","companions":[{"measured":2015,"magnitude":12.58,"components":"AB","discoverer_code":"H 5  79","separation_arcsec":82.4,"position_angle_deg":330},{"measured":2015,"magnitude":12.73,"components":"AC","discoverer_code":"SMY   5","separation_arcsec":150.7,"position_angle_deg":238},{"measured":2012,"magnitude":8.24,"components":"AD","discoverer_code":"S   838","separation_arcsec":244,"position_angle_deg":197}],"spectral_type":"A1II-III","color_index_bv":0.274,"radial_velocity_km_s":-18,"spectral_type_source":"SIMBAD (1987ApJS...65..581G, quality C)","proper_motion_ra_mas_yr":-0.99,"proper_motion_dec_mas_yr":-0.37},"designations":[{"catalog":"Bayer/Flamsteed","designation":"9 Cas"},{"catalog":"HD","designation":"HD 225180"},{"catalog":"HIP","designation":"HIP 330"},{"catalog":"HR","designation":"HR 9100"}],"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."}