{"865ef5b00fbdd3c82c9750ce6653a805asteroidguy":{"DOI":"","ISBN":"","ISSN":"","URL":"","abstract":"We present results obtained from a stellar occultation by the classical Kuiper belt object (174567) Varda on 10 September 2018. Varda is a known binary system and among the largest TNOs known today, but has not been studied during an occultation before. Among our collaborators, 24 stations were able to acquire data at the time of the event, of which 15 obtained a clear detection, making this the best-sampled occultation of a TNO to date. As potential stellar duplicity could cause a significant shift of the ground path, we studied the target star in advance through speckle imaging with 'Alopeke at Gemini North. The reconstructed shape is an ellipsoid, which supports Varda's status as a dwarf planet candidate. Albeit slightly smaller, the calculated size is in agreement with the radiometric diameter based on Herschel/PACS FIR measurements. Post-event analysis of the dataset obtained at DCT revealed a faint, unresolved companion or background star very close to the target, which was well under the detection limit of our speckle imager data, but had practically no effect on the predicted path. No atmosphere has been detected. The occultation helped to constrain size and albedo, which in turn helps to better constrain Varda's density....","annote":"","author":[{"family":"Schindler","given":"K."},{"family":"Bosh","given":"A. S."},{"family":"Levine","given":"S. E."},{"family":"Person","given":"M. J."},{"family":"Wolf","given":"J."},{"family":"Zuluaga","given":"C."},{"family":"Krabbe","given":"A."}],"citation-label":"schindler2019results","collection-editor":[],"collection-title":"","container-author":[],"container-title":"AGU Fall Meeting Abstracts","documents":[],"edition":"","editor":[],"event-date":{"date-parts":[["2019","12"]],"literal":"2019"},"event-place":"","id":"865ef5b00fbdd3c82c9750ce6653a805asteroidguy","interhash":"f835d4bfeb603bb750b040984548f31b","intrahash":"865ef5b00fbdd3c82c9750ce6653a805","issue":"","issued":{"date-parts":[["2019","12"]],"literal":"2019"},"keyword":"ATUS SOFIA astronomy imported myown","misc":{"bibcode":"2019AGUFM.P42C..08S"},"note":"","number":"","page":"","page-first":"","publisher":"","publisher-place":"","status":"","title":"Results from a stellar occultation by KBO Varda","type":"article","username":"asteroidguy","version":"","volume":""},"530b988ca6687d22a9dcf1c76f919084asteroidguy":{"DOI":"10.1117/12.2237207","ISBN":"","ISSN":"","URL":"https://www.dsi.uni-stuttgart.de/institut/mitarbeiter/schindler/Wolf_et_al._2016.pdf","abstract":"The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a 2.5-meter infrared telescope built into a Boeing 747SP. In 2014 SOFIA reached its “Full Operational Capability” milestone and nowadays takes off about three times a week to observe the infrared sky from altitudes above most of the atmosphere's water vapor content. Despite reaching this major milestone, efforts to improve the observatory's performance are continuing in many areas. The team of the Deutsches SOFIA Institut, DSI (German SOFIA Institute) at the SOFIA Science Center in Moffett Field, CA works in several engineering areas to improve the observatory's performance and its efficiency. DSI supports the allocation process of SOFIA's observation time for guest observers, provides and supports two facility science instruments and conducts an observing program of stellar occultations by small objects of the solar system. This paper summarizes results and ongoing work on a spare secondary mirror made of aluminum, the new and improved Focal Plane Imager (FPI+) that has become a facility science instrument, the Field-Imaging Far-Infrared Line Spectrometer (FIFI-LS), new cameras and optics for the Fine Field and Wide Field Imagers (FFI+ and WFI+), real-time astrometric solution of star field images, ground support equipment and astronomical observations.","annote":"","author":[{"family":"Wolf","given":"Jürgen"},{"family":"Colditz","given":"Sebastian"},{"family":"Lachenmann","given":"Michael"},{"family":"Pfüller","given":"Enrico"},{"family":"Schindler","given":"Karsten"},{"family":"Wiedemann","given":"Manuel"},{"family":"Zinnecker","given":"Hans"},{"family":"Krabbe","given":"Alfred"}],"citation-label":"Wolf2016","collection-editor":[],"collection-title":"","container-author":[],"container-title":"Proc. SPIE","documents":[],"edition":"","editor":[],"event-date":{"date-parts":[["2016"]],"literal":"2016"},"event-place":"","id":"530b988ca6687d22a9dcf1c76f919084asteroidguy","interhash":"e7ba662515119ff172ad181b1ff822e7","intrahash":"530b988ca6687d22a9dcf1c76f919084","issue":"","issued":{"date-parts":[["2016"]],"literal":"2016"},"keyword":"ATUS SOFIA myown","misc":{"doi":"10.1117/12.2237207"},"note":"","number":"","page":"99730J-99730J-14","page-first":"99730","publisher":"","publisher-place":"","status":"","title":"Deutsches SOFIA Institut (DSI) at the SOFIA Science Center: engineering and scientific contributions to the airborne observatory","type":"article-journal","username":"asteroidguy","version":"","volume":"9973"},"0a85c83e74fd2b2d3ea8ea3f956c9facasteroidguy":{"DOI":"10.1117/12.2231531","ISBN":"","ISSN":"","URL":"https://www.dsi.uni-stuttgart.de/institut/mitarbeiter/schindler/Schindler_et_al._2016.pdf","abstract":"SOFIA is an airborne observatory, operating a gyroscopically stabilized telescope with an effective aperture of 2.5 m on-board a modified Boeing 747SP. Its primary objective is to conduct observations at mid- to far-infrared wavelengths. When SOFIA opens its door to the night sky, the initial telescope pointing is estimated from the aircraft's position and heading as well as the telescope's attitude relative to the aircraft. This initial pointing estimate needs to be corrected using stars that are manually identified in tracking camera images; telescope pointing also needs to be verified and refined at the beginning of each flight leg. We report about the implementation of the astrometry.net package on the telescope operator workstations on-board SOFIA. This package provides a very robust, reliable and fast algorithm for blind astrometric image calibration. Using images from SOFIA's Wide Field Imager, we are able to display an almost instant, continuous feedback of calculated right ascension, declination and field rotation in the GUI for the telescope operator. The computer-aided recognition of star patterns will support telescope pointing calibrations in the future, further increasing the efficiency of the observatory. We also discuss other current and future use cases of the astrometry.net package in the SOFIA project and at the German SOFIA Institute (DSI).","annote":"","author":[{"family":"Schindler","given":"Karsten"},{"family":"Lang","given":"Dustin"},{"family":"Moore","given":"Liz"},{"family":"Hümmer","given":"Martin"},{"family":"Wolf","given":"Jürgen"},{"family":"Krabbe","given":"Alfred"}],"citation-label":"Schindler2016","collection-editor":[],"collection-title":"","container-author":[],"container-title":"Proc. SPIE","documents":[],"edition":"","editor":[],"event-date":{"date-parts":[["2016"]],"literal":"2016"},"event-place":"","id":"0a85c83e74fd2b2d3ea8ea3f956c9facasteroidguy","interhash":"d101b4bfdad6196a739a6c97a6922014","intrahash":"0a85c83e74fd2b2d3ea8ea3f956c9fac","issue":"","issued":{"date-parts":[["2016"]],"literal":"2016"},"keyword":"ATUS SOFIA myown","misc":{"doi":"10.1117/12.2231531"},"note":"","number":"","page":"991307-991307-14","page-first":"991307","publisher":"","publisher-place":"","status":"","title":"Computer-aided star pattern recognition with astrometry.net: in-flight support of telescope operations on SOFIA","type":"article-journal","username":"asteroidguy","version":"","volume":"9913"}}