iTelescope - T27 - Deep Space - Australia


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Location Information


Observatory: iTelescope.Net at Siding Spring Observatory Australia - MPC Q62

Telescope:  0.70-m f/6.6 reflector + CCD

Timezone:  UTC +10:00 New South Wales, Australia Daylight savings time is observed.

Minimum Target Elevation: Approx 30-35 Degrees


South 31° 16' 24" East 149° 03' 52"  

Elevation: 1122m 


Operational Notes


Very Deep Field. Hybrid Missions. Typically used for Photometry and Imaging. FITS and TIF file formats. Sub-exposure times should be kept to  60, 120, 180, 300, 600 seconds for optimal results. Binx1 - Binx2. Best results on Binx1.  Raw data can be found at data.itelescope.net.


  • Recommended Maximum Exposure 300 seconds.  Maximum Exposure Time 600 seconds.
  • The Planewave CDK700 mount is so accurate whilst tracking that iTelescope Admin have disabled active guidance, with a corresponding decrease in session setup time when imaging.
  • T27 is the largest iTelescope platform on the network at 27.5" (.7 meters). It has a rapid slewing Alt-Azm mount with built in de-rotator and is ideal for very deep imaging, comet or asteroid studies and deep science missions in general. 
  • Important:
  • T27 as well as T24 and T31 all use RBI flooding to flush the CCD wells of any residual data from the previous images.
  • If this is not done then ghost images of bright objects like stars can remain on the chip when another user selects a new target. They appear as faint ghost like images of stars or spots in the image. So we flush the CCD of any old data and clean the images for following users or different targets.
  • We MUST also produce MATCHING Bias / Darks calibration data that includes this RBI flush in order to produce acceptable images. This calibration data MUST match the exposure lengths of the image. Eg. 60, 120, 180, 300, 600 seconds.
  • So if your imaging sessions on T27 are for example using 150 second exposures then NO MATCHING CALIBRATION data will be able to be applied by the telescope server to automatically remove the RBI flush effect from your data. If you use our standard and recommended exposure times the RBI artifacts will not appear. You of course have the option of taking your own custom Dark Calibration during your session and applying this calibration yourself post session.
  • T27 is also on an Alt/Az mount.  These mounts are extremely accurate but can suffer from tracking (streaked or rotataing stars) at high altitudes (75º+).  This is simply due to the nature of Alt/Az mounts - near zenith, the mount and rotator must slew at a much higher rate of speed to keep your target in frame.   Please use caution when imaging targets near zenith. 
  • Imagers Note: For best results please use only Binx1.


This iTelescope platform is dedicated to three women whose contributions to the field of astronomy over the last century were very influential and still remain so to this very day -  Dame Jocelyn Bell Burnell, Annie Jump Cannon and Henrietta Swan Leavitt (BCL). Hence, this instrument has been named “The BCL iTelescope”.



We hope that you will enjoy using this research grade telescope to make your own discoveries and to share your enthusiasm and results with others.


Instrument Package


CCD:  FLI PL09000

QE: 68% Peak

Full Well:  > 100X Saturation Exposure (ABG)

Dark Current:   <0.1 e-/pixel/sec. @ -35º C

Pixel Size:  12um Square

Resolution:  0.53 arc-secs/pixel

Sensor:  Frontlit 

Cooling:  Set to -35ºC default 

Array:  3056 by 3056 (9 Megapixels) 

FOV:      27.1 x 27.1 arc-mins

Filters:  Astrodon E series - Lum, Green, Blue.

Astrodon - Ha 6nm, SII 6nm, OIII 6nm.

Astrodon Johnson/Cousins V, Rs, Ic.

Position Angle:



Telescope Optics


OTA: Planewave 27" (0.7m) CDK700WF

Optical Design: Corrected Dall-Kirkham Astrograph

Aperture: 700mm

Focal Length: 4531mm

F/Ratio: f/6.6

Guiding: Active Guiding Disabled 

Mount: Planewave Alt-Az