The Isaac Newton Telescope or INT is a 2.54 m (100 in) optical telescope run by the Isaac Newton Group of Telescopes at Roque de los Muchachos Observatory on La Palma in the Canary Islands since 1984.
Originally the INT was situated at Herstmonceux Castle in Sussex, England, which was the site of the Royal Greenwich Observatory after it moved away from Greenwich due to light pollution. It was inaugurated in 1967 by Queen Elizabeth II.
Herstmonceux suffered from poor weather, and the advent of mass air travel made it plausible for UK astronomers to run an overseas observatory. In 1979, the INT was shipped to La Palma, where it has remained ever since. It saw its second first light in 1984, with a video camera.
Until 2024, the main instruments were the Wide Field Camera (WFC) and Intermediate Dispersion Spectrograph (IDS). WFC is a four CCD photographic prime-focus instrument with a relatively large 0.56×0.56 square degree field of view, which was commissioned in 1997. IDS is a medium-low resolution optical spectrograph (R 550-9375). As of mid 2024 the INT is undergoing upgrades in preparation for the installation of HARPS3, after which it will be the main instrument.
The old site of the INT is now the Observatory Science Centre at Herstmonceux, and it is known for its distinctive greened copper dome and various science and astronomy activities.
Summary Background up to 1979
left|thumb|The INT dome at the former Royal Greenwich Observatory, Herstmonceux
left|thumb|Aerial view of the former Royal Greenwich Observatory, Herstmonceux. The INT dome is the single dome to the right
The United States gifted a 98-inch mirror in 1949 to the United Kingdom. (In a telescope this could establish the 3rd largest in the World, behind only the Hale and Hooker telescopes at that time). After ten years the mount was ordered for the telescope, and in 1959 construction began on what would be the INT, and it was completed by 1965; first light at Herstmonceux was conducted that year. The Royal Greenwich Observatory completed its move to Herstmonceux in 1956. (reflecting telescopes of this type need the glass blank ground into a precise shape, which can take years).
The telescope's first light (first, first light) occurred in 1965, and it was dedicated in 1967.
On December 1, 1967, the Isaac Newton Telescope of the Royal Greenwich Observatory at Herstmonceux was inaugurated (dedicated) by Queen Elizabeth II. Although the telescope was acquitting itself, the weather at the site less so. This eventually led to the plan to move the telescope to a new observatory, which would occur in the next decade and into the early 1980s. The new telescope for the island had so many new parts however, it was deemed possible in the mid-1980s to essentially fork the telescope design into two working telescopes with some rejuvenation. This would mean having another functioning telescope at Sussex; however, this project was terminated. One issue is that it would mean operating two telescopes, and the focus at that time had shifted to operating the new INT on the island. The old site would eventually be turned into a science museum with much of the old telescopes left as they were.
The old observatory buildings remain by the Castle, and it is the site of the Herstmonceux Science Centre (aka Observatory Science Centre at Herstmonceux).
The new 100 inch Zerodur-glass mirror arrived at La Palma in December 1982.
1967
The INT was inaugurated by Queen Elizabeth II in 1967. The largest optical telescopes in 1967 included:
{| class="wikitable" style="font-size: 90%; text-align: center;"
|-
! #BBEEFF;"| #
! style="background:#bef;"| Name /<br /> Observatory
! style="width:40px; background:#bef;"| Image
! style="background:#bef;"| Aperture
! style="background:#bef;"| Altitude
! style="background:#bef;"| First <br />Light
<!-- ! style="background: #BBEEFF;" | Note -->
|-
! 1
| 5m Hale Telescope <br /> Palomar Obs.
| 50px
| 200″ <br /> 508 cm
| 1713 m <br /> (5620 ft)
| 1949
|-
! 2
| C. Donald Shane telescope <br /> Lick Observatory
| 40px
| 120″ <br /> 305 cm
| 1283 m <br />(4209 ft)
| 1959
|-
! 3
| Shajn 2.6m (Crimean 102 in.) <br /> Crimean Astrophysical Obs.
| 40px
| 102″ <br /> 260 cm
| 600 m <br /> (1969 ft)
| 1961
|-
! 4
| Hooker Telescope <br> Mount Wilson Obs.
| 30px
| 100″ <br> 254 cm
| 1742 m <br />(5715 ft)
| 1917 <!--Inactive 1986-1992 -->
|- style="background:#DAF7A6" <!-- style="background:#efefef;" grey-->
! 5
| Isaac Newton Telescope <br /> Royal Greenwich Obs. (1967-1979)
| 50px
| 98″ <br> 249 cm
|
| 1965
| 2168 m <br> (7,113 ft)
| 1984
|-
! n
| Shane Telescope <br /> Lick Observatory
| 40px
| 120″ <br /> 305 cm
| m<sup>2</sup>
| 1283 m <br />(4209 ft)
| 1959
|-
! n
| Harlan J. Smith Telescope <br /> McDonald Observatory
| 40px
| 107″ <br /> 270 cm
|
| 2070 m <br /> (6791 ft)
| 1968
|-
! n
| Shajn 2.6m (Crimean 102 in.) <br /> Crimean Astrophysical Obs.
| 40px
| 102″ <br /> 260 cm
|
| 600 m <br /> (1969 ft) and aims to start observations in March 2025. It is being built as part of the Terra Hunting Experiment - a future 10 year radial velocity measurement program to discover Earth-like exoplanets. It has a goal to achieve 10 cm/s radial velocity precision.
See also
- Isaac Newton
- Newton's reflector (a reflector made by Isaac Newton in the 1600s)
- Newtonian telescope (a telescope design)
- International Year of Astronomy commemorative coin
- The INT Photometric H-Alpha Survey (IPHAS), an astronomical survey of the northern plane of the Milky Way Galaxy by this telescope
References
External links
- INT Homepage
- Stock Photo of old 98 inch mirror at Herstmonceux Science Center
- INT article (2012)