The Infrared Survey Facility consists of a dedicated telescope and simultaneous three-channel imager called SIRIUS for
specialized surveys of the southern hemisphere sky in the infrared J(1.25 micron), H(1.65 micron) and
K'(2.15 micron) bands. It is a joint Japanese/South African project.


The telescope for the Facility is a 1.4m F10 altazimuth Cassegrain instrument constructed by the Nishimura
Telescope Company in Kyoto, Japan. Installation of telescope and camera at Sutherland took place September-November 2000.
The optics were made by LOMO, St Petersburg, from Astro-Sitall glass ceramic.
Parabolic primary paraxial radius = 8122mm; 1/6.5 wave at 0.63 microns; usable diam = 1395mm
Hyperbolic secondary conjugates = 1401mm, 3640mm; diam = 400mm
Mirror separation = 2985mm
Focal plane 200mm below mounting flange
System focal length = 13800mm

Almost complete dome (31Kb)

At Nishimura works (35Kb)

Telescope in dome (60Kb)

Telescope from above (50Kb)


The Sirius (Simultaneous-3color InfraRed Imager for Unbiased Survey) imager is a simultaneous 3-channel JHK'
device using three 1024 x 1024 HgCdTe arrays. It was constructed at Nagoya University. It has an Offner relay
imaging system with cold pupil stop. It is cooled by a closed-cycle refrigerator. The field is approximately 7.8' x 7.8'.
Sirius home page

International Agreement

The construction and operation of the facility is covered by an agreement, dated August 3, 1998, between the
South African Astronomical Astronomical Observatory and the Graduate School of Science and School of Science,
Nagoya University.

The division of time on the instrument is:


Preliminary design of building by Digby Ellis, SAAO, in consultation with T. Nagata and I.S. Glass
Detailed building design and contract superintendence by Dr A. Lloyd of Zietsman, Lloyd and Hemsted Inc, Hout Bay
Building construction by Alpha Civils, Worcester, Sep-Dec 1999
Dome erection by Richard Olson (Ashdome) and SAAO staff, March 2000
Special installations (e.g. LAN) by P. Fourie and other SAAO instrumentation staff
Telescope erection Sept 2000
Official opening 15 November 2000

Further details: Available in article "Infrared Survey Facility at Sutherland" by T. Nagata and I.S. Glass, MNASSA 59, 110-115.

Applying for observing time: South Africa - based observers can apply for time with the usual SAAO deadlines.

Information by I.S. Glass, Project Coordinator for SAAO

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