The Isaac Newton Group of Telescopes comprises the 4.2-m William Herschel Telescope, the 2.5-m Isaac Newton Telescope and the 1.0-m Jacobus Kapteyn Telescope. The instrument information on the WHT home page supercedes that given below.
A range of support services is also operated, plus a sea-level base.
The telescopes have complementary roles, namely:
Each telescope is equipped with a range of "common-user" instruments supporting these functions.
Biographies are available for William Herschel, Isaac Newton and Jacobus Kapteyn.
Pictures: ING from the air, ING from the Roque de los Muchachos.
William Herschel Telescope
The William Herschel Telescope is the largest of the telescopes at the Canarian Observatories, indeed it is the largest in Western Europe. It has an altazimuth mount with a 4.2-metre diameter f/2.5 parabolic primary mirror. Instruments can be mounted at the corrected f/2.81 prime focus, f/11 cassegrain focus, or either of two f/11 Nasmyth foci. Total weight of the telescope is 210 tonnes, and the pointing accuracy is 1 - 1.5 arcsec rms.
The telescope is a general purpose facility, instrumented to allow a wide range of astronomical observations. The instruments currently offered on a common-user basis are summarised below.
Pictures:
WHT dome,
building cutaway,
telescope,
telescope schematic,
mirror cell,
mirror,
cass instrument cluster,
control room,
| Instrument | Brief Description |
|---|---|
| ISIS | Intermediate dispersion spectrograph, with red and blue arms operated simultaneously, and polarimetric capability |
| UES | High-dispersion echelle spectrograph, operated in either single-order longslit mode, or multi-order cross-dispersed mode |
| TAURUS | Wide-field Fabry-Perot interferometer |
| LDSS | Multi-object spectrograph using aperture plates to observe up to 150 targets simultaneously |
| AUTOFIB/WYFFOS | Multi-object spectrograph using fibre feeds to observe up to 150 targets simultaneously |
| INTEGRAL/WYFFOS | Coherent-bundle fibre feeds to WYFFOS spectrograph |
| Prime focus camera | Wide-field CCD imager |
| Auxiliary port camera | High resolution CCD imager |
| INGRID | InfraRed imager (under development) |
| NAOMI | Common-user Adaptive Optics system (under development) |
Isaac Newton Telescope
The Isaac Newton Telescope has a 2.54-metre primary mirror with a focal ratio of f/2.94. It uses a polar-disc/fork type of equatorial mount. Instruments can be mounted at the corrected f/3.29 prime or f/15 cassegrain foci. Total weight of the telescope is 109 tonnes, and the pointing accuracy is 2-3 arcsec rms.
The role of the telescope is as a facility for wide-field imaging and intermediate to low dispersion spectroscopy. The instruments currently offered on a common-user basis are summarised below.
Pictures: INT dome,
INT telescope
| Instrument | Brief Description |
|---|---|
| IDS | Intermediate dispersion spectrograph |
| FOS | Faint object spectrograph, optimised for high throughput and low dispersion |
| Prime focus camera | Wide-field CCD imager |
Jacobus Kapteyn Telescope
The Jacobus Kapteyn Telescope has a parabolic primary mirror of diameter 1.0 m. It is equatorially mounted, on a cross-axis mount. Instruments can be mounted at the f/15 cassegrain focus. Total weight of the telescope is 15.5 tonnes, and the pointing accuracy is 15-20 arcsec rms.
The role of the telescope is as a facility for CCD imaging. The instrument currently offered on a common-user basis is shown below:
Pictures:
JKT dome,
JKT telescope
| Instrument | Brief Description |
|---|---|
| CCD camera | Optical imaging |
