"Helen Sawyer Hogg" Telescope

The Helen Sawyer Hogg 60-cm telescope is owned by the University of Toronto, Canada, and between 1971 and 1997 it was in operation at Las Campanas Observatory in Chile.

The telescope is currently located at the Burek mountain (long.= 4h 37m 13.54s W; lat.=-31°47' 14.46"; alt.=2591 m a.s.l.) and is being operated by CASLEO.

This instrument, whose optical system is a standard Cassegrain reflector, was built by the Ealing Corporation and is mounted on a German off-axis system.


Main Optical Data

Primary mirror diameter:609.6 mm
Cassegrain focal ratio:15
Effective focal length:9131.33 mm
Secondary mirror diameter:172.3 mm

Other Data

Focal lenngth of the primary:2132.07 mm
Primary - secondary distance:1595.88 mm
Weight of primary mirror:60 kg
Finder telescope:Refractor
Finder telescope diameter:152 mm

Peripheral Instruments

The HSH is equipped with a spectrograph and a direct camera. The spectrograph has gratings of 67 and 120 Å/mm which make it possible to achieve a dispersion of 40 and 109 Å/mm, respectively. The main detector is a ST-8 SBIG with a KAF 1603ME chip. The main characteristics of the chip are shown in the Table below. The figure shows the quantum efficiency for the chip.


ST-8 CCD Data
(by manufacturer's specifications)
rows × columns1530 × 1020
pixel size9 × 9 µ
chip size13.8 mm × 9.2 mm
gain 2.5 e-/ADU
read-out noise<15 e-
dark current<1 e-/seg/pixel
A/D converter 16 bits
read-out time 3.7 seg

The available filters are:

  B=  2mm BG12 + 2mm GG385
  V=  3mm BG18 + 3mm GG495 + 3mm BG18
  R=  2mm OG550 + 3mm KG1 + 1mm RG6
  I=  1mm RG780 + 3mm RG715

Other Information

A series of useful operating instructions to read correctly coordinates, set the time and to operate with different acquisition software could be found in the personal web page of Dr. Eduardo Fernández Lajús.