scholarly journals CIRCE: The Canarias InfraRed Camera Experiment for the Gran Telescopio Canarias

2018 ◽  
Vol 07 (01) ◽  
pp. 1850002 ◽  
Author(s):  
Stephen S. Eikenberry ◽  
Miguel Charcos ◽  
Michelle L. Edwards ◽  
Alan Garner ◽  
Nestor Lasso-Cabrera ◽  
...  

The Canarias InfraRed Camera Experiment (CIRCE) is a near-infrared (1–2.5[Formula: see text][Formula: see text]m) imager, polarimeter and low-resolution spectrograph operating as a visitor instrument for the Gran Telescopio Canarias (GTC) 10.4-m telescope. It was designed and built largely by graduate students and postdocs, with help from the University of Florida (UF) astronomy engineering group, and is funded by the UF and the US National Science Foundation. CIRCE is intended to help fill the gap in near-infrared capabilities prior to the arrival of Especrografo Multiobjecto Infra-Rojo (EMIR) to the GTC and will also provide the following scientific capabilities to compliment EMIR after its arrival: high-resolution imaging, narrowband imaging, high-time-resolution photometry, imaging polarimetry, and low resolution spectroscopy. In this paper, we review the design, fabrication, integration, lab testing, and on-sky performance results for CIRCE. These include a novel approach to the opto-mechanical design, fabrication, and alignment.

1992 ◽  
Vol 104 ◽  
pp. 441 ◽  
Author(s):  
Klaus-Werner Hodapp ◽  
John Rayner ◽  
Everett Irwin

2020 ◽  
Vol 500 (3) ◽  
pp. 3920-3925
Author(s):  
Wolfgang Brandner ◽  
Hans Zinnecker ◽  
Taisiya Kopytova

ABSTRACT Only a small number of exoplanets have been identified in stellar cluster environments. We initiated a high angular resolution direct imaging search using the Hubble Space Telescope (HST) and its Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) instrument for self-luminous giant planets in orbit around seven white dwarfs in the 625 Myr old nearby (≈45 pc) Hyades cluster. The observations were obtained with Near-Infrared Camera 1 (NIC1) in the F110W and F160W filters, and encompass two HST roll angles to facilitate angular differential imaging. The difference images were searched for companion candidates, and radially averaged contrast curves were computed. Though we achieve the lowest mass detection limits yet for angular separations ≥0.5 arcsec, no planetary mass companion to any of the seven white dwarfs, whose initial main-sequence masses were >2.8 M⊙, was found. Comparison with evolutionary models yields detection limits of ≈5–7 Jupiter masses (MJup) according to one model, and between 9 and ≈12 MJup according to another model, at physical separations corresponding to initial semimajor axis of ≥5–8 au (i.e. before the mass-loss events associated with the red and asymptotic giant branch phase of the host star). The study provides further evidence that initially dense cluster environments, which included O- and B-type stars, might not be highly conducive to the formation of massive circumstellar discs, and their transformation into giant planets (with m ≥ 6 MJup and a ≥6 au). This is in agreement with radial velocity surveys for exoplanets around G- and K-type giants, which did not find any planets around stars more massive than ≈3 M⊙.


2004 ◽  
Author(s):  
Paul Martini ◽  
S. E. Persson ◽  
David C. Murphy ◽  
Christoph Birk ◽  
Stephen A. Shectman ◽  
...  

Author(s):  
Tamim Ahmed ◽  
Khandker Sadia Rahman ◽  
Sk Subrina Shawlin ◽  
Mohammad Hasan ◽  
Arnab Bhattacharjee ◽  
...  

2021 ◽  
Vol 34 (Supplement_1) ◽  
Author(s):  
Subramanyeshwar Rao Thammineedi

Abstract   Post esophagectomy anastomotic leakage and stricture are crucial factors in determining morbidity and mortality. Good vascularity of the gastric conduit is essential to avoid this complications. This prospective study assesses the utility of intraoperative indocyanine green (ICG) fluorescence imaging to determine gastric conduit vascularity in patients undergoing esophagectomy. Methods Thirteen consecutive patients who were undergoing esophagectomy for carcinoma middle, lower third esophagus or gastro-esophageal junction from August 2019 to September 2019, were included. Three patients underwent laparoscopic-assisted transhiatal esophagectomy, ten thoraco-laparoscopic assisted esophagectomy. Reconstruction was done by gastric pull up via posterior mediastinal route. Vascularity of gastric conduit was assessed by the near-infrared camera using ICG. Results On visual assessment of perfusion at the tip of gastric conduit, it was dusky in 11 patients, pink in two. Fuorescence imaging showed inadequate perfusion at the tip of conduit in 12 patients, needing revision. In one patient visual inspection showed adequate perfusion, but ICG disclosed poor vascularity requiring revision of the conduit’s tip. Resection of the devitalized portion of the proximal esophageal stump was needed in 5 patients both by visual and ICG assessment. The median time to appearance of blush from the time of injection of dye was 15 seconds (10 to 23 seconds). Conclusion Visual inspection of the gastric conduit vascularity can underestimate perfusion and hence can compromise resection of the devitalized part. ICG fluorescence imaging is more objective and promising means to ascertain the vascularity of gastric conduit during an esophagectomy. It could complement the visual inspection to decide the site of anastomosis.


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