{"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":"2026-09-02T14:11:02.050Z","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-19978","name":"HD 19978","class":"a6v_white_main_sequence_star","category":"star","object_type":"A6V white main-sequence star","mag":5.44,"mag_band":"V","abs_mag":0.893,"abs_mag_band":"V","distance_ly":264.73721791614804,"distance_method":"parallax","ra_deg":50.081745,"dec_deg":77.73474,"epoch_ra_deg":50.954083,"epoch_dec_deg":77.831069,"epoch_moved_arcsec":2.472,"pm_ra_mas_yr":64.9,"pm_dec_mas_yr":-66.2,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Cepheus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-19978","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"03203+7744","companions":[{"measured":1984,"magnitude":12.3,"components":"AB","discoverer_code":"BU 1176","separation_arcsec":0.7,"position_angle_deg":271},{"measured":2011,"magnitude":13.1,"components":"AC","discoverer_code":"BU 1176","separation_arcsec":13.5,"position_angle_deg":274}],"spectral_type":"A6V","color_index_bv":0.211,"luminosity_solar":38.26484865951095,"radial_velocity_km_s":4,"spectral_type_source":"SIMBAD (2007A&A...463..671R, quality D)","surface_temperature_k":7780,"proper_motion_ra_mas_yr":64.9,"proper_motion_dec_mas_yr":-66.2,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"HD","designation":"HD 19978"},{"catalog":"HIP","designation":"HIP 15547"},{"catalog":"HR","designation":"HR 961"}],"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."}