Subaru Telescope NAOJ

Collaborative works at Kottamia Observatory in Egypt

Sister Telescope of OAO 74” Middle Telescope Network over Middle-East and Asia

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since 2009/06/25

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• Work Reports done during June, 2009
  
  • Detailed Work reports conducted at Kottamia Station and its telescope problem (in Japanese; 9KB) , and the same work reports (in English; 14KB)
    
    

    Image before June 6, 2009 .

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    Image around M13 after adjustment on June 10, 2009

    1. Adjustment of Primary Mioor(M1)：We found that three axial fixed support (Axial Fixation Point AFP) pads are higher towards M1 above other movable axial support(AS) pads. By sinking those AFP pads and adjusting other AS pads, we successfully improved the stellar images to normal single-shaped round images than 3-segmented images before. We confirmed that stellar images keep being round over the sky by moving the telescope. Our main purpose of this trip is acheived successfully.
    2. CCD 10' FOV was shifted mechanically to the new coma-free center (with diameter about 2'). Coma-free field is found to be shifted by about 4' by changing the telescope north to south. This shift may be occured by a mount gap inside the Newtonian mirror or/and a flexure of spiders for Newtonian mirror. It must be adjusted for mount system inside the Newtonian mirror and the spiders. If not adjusted, we propose that installation of a XY slider mechanics is necessary for Newtonian instruments to compensate the shift of Coma-free region.
    3. By measuring the optical axis with a laser beam gun attached to Cassegrain(Cs) focus, CCD mount at the Newtonian focus was shifted to match the optical axis.
    4. We discussed about the future collaborations between Egypt and japan on the Kottamia Telescope and Astronomy.
       1. As we found a free space around the limiter for AS counter balance looks too tight, we propose to expand the free spaces to widen the counter balance up-down ranges to M1, which can be done on our next visit.
       2. We propose a CO2 snow cleaning method which cleans up the dust on M1.
       3. We propose an installation of a XY slider mechanics for Newtonian instruments to compensate the shift of Coma-free region.
       4. We propose a new installation of a Cassegrain buffle inside the telescope tube.
       5. We propose modification of flat-field ilumination for Cassegrain instruments (Note-1).
       6. We discuss about remote control of Cs sprectrograph.
       7. We propose our new method of "Pre-Wet" in aluminizing mirrors, M1 and M2.
       8. We propose to install a light-blocking screen on another side of telescope tube to Newtonian focus.
       9. We propose to carry out the Hartmann test to invetigate the coma-free field at Newtonian FOV. We express to create and provide to Kottamia people our new software to analyze the Hartmann test images on Microsoft Windows.
          
          
          (* Note-1) By conducting with Dr. Yoshida at OAO, he said that a flat-field illumination at Cassegrain (Cs), reflecting the Cs screen, is not used at Subaru telescope currently as it doesn't pass through the whole telescope optics. Dome flat-fielding is normally as a standard for Cs spectrograph, FOCAS (2009-06-17). We must consider the flat-field illumination should be based using dome flat-field ilumination for Cs spectrograph for Kottamia Telescope.
    
    
    
  • PhotoReport200906 on works at Kottamia done during 2009 Jun 07 - Jun 12

    Short Report with some photos in MS-WORD format (2.6MB)

    
    
    
  • PPT file of Report200906 on works at Kottamia done during 2009 Jun 07 - Jun 12

    Report in PPT format (4.4MB)

    
    
  • Sasaki's Memo during the visit in June, 2009
    hand-writing memo during June/2009 visit in Kottamia and Cairo (in Japanese; 21.9MB)
    
    
  • A list of axial lengths of Axial Support System, measured by Carl-Zeiss (gif; 244KB)
    
    
  • Hartmann Test to evaluate optical performance of the telescope using Hartmann Plate
    
    • Hartmann test during June, 2009
      Observations for Hartmann Test have been done on July 21, 2009. Those image data are analyzed to show its Hartmann Constant about 0.67 arcsec, including a part of Coma and Astigmatism. See details, please click here.
      
      Hartmann test should be done again after optical adjustment.
      
      

      Hartmann Plate on tube top

      Distribution of Residual vector for Hartmann Test images

      Expected image at Best focus

    
    
    
  • Photos200906 at Kottamia (click a thumbnail image to view the photos on another TAB page)

    Site	Sasaki Photos	Noguchi Photos	Egypt Photos
    Kottamia

  
  
  

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• Photos200906 in Cairo (click a thumbnail image to view the photos on another TAB page)

  Site	Sasaki Photos	Noguchi Photos
  Cairo

  
  
  

top	Kottamia Observatory	Work Items	Reports on our Visit		CO2 Snow	Hartmann	DomeFlat	Docs	References	bottom
			2009 Jun	2009 Nov

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