{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.679","julian_year":2026.679,"time":"2026-09-05T22:41:43.162Z","years_from_j2000":26.679,"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-163336","name":"HD 163336","class":"a0v_white_main_sequence_star","category":"star","object_type":"A0V white main-sequence star","mag":5.93,"mag_band":"V","abs_mag":1.585,"abs_mag_band":"V","distance_ly":241.2399339963007,"distance_method":"parallax","ra_deg":269.079315,"dec_deg":-15.812521,"epoch_ra_deg":269.465766,"epoch_dec_deg":-15.817199,"epoch_moved_arcsec":1.784,"pm_ra_mas_yr":-9.61,"pm_dec_mas_yr":-66.17,"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-163336","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"17563-1549","companions":[{"measured":2022,"magnitude":6.97,"components":"Aa,Ab","discoverer_code":"WAI   1","separation_arcsec":0.4,"position_angle_deg":339},{"measured":2021,"magnitude":12.4,"components":"AD","discoverer_code":"DRS  62","separation_arcsec":2.6,"position_angle_deg":39},{"measured":2006,"magnitude":9.16,"components":"AB","discoverer_code":"HJ 2814","separation_arcsec":20.6,"position_angle_deg":157},{"measured":2000,"magnitude":12.59,"components":"AC","discoverer_code":"HJ 2814","separation_arcsec":39.3,"position_angle_deg":350}],"spectral_type":"A0V","color_index_bv":0.024,"luminosity_solar":20.23019178678272,"radial_velocity_km_s":-24,"spectral_type_source":"SIMBAD (1988MSS...C04....0H, quality C)","surface_temperature_k":9290,"proper_motion_ra_mas_yr":-9.61,"proper_motion_dec_mas_yr":-66.17,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"HD","designation":"HD 163336"},{"catalog":"HIP","designation":"HIP 87813"},{"catalog":"HR","designation":"HR 6681"}],"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."}