| Large Solar Optical Telescopes |
Large aperture is a necessary but not sufficient condition for high resolution observations. Other requirements include optical quality, site selection, and a telescope design that takes best advantage of the site. The ultimate resolution limit of an optical telescope depends on the aperture and the wavelength of light being observed and is caused by diffraction. Adaptive optics can now allow ground-based telescopes to reach their diffraction limits. Space-based telescopes reach their diffraction limits much more easily. Somewhat arbitrarily we have defined 50 cm aperture as large in the following list.
The physically largest solar telescopes are fixed telescopes with very long focal lengths. These provide the most convenient arrangements for performing experiments. In the list these are designated as tower telescopes. Spar telescopes (by "spar" we mean a telescope in which the first focus moves around rather than being at a fixed observing table) of the same aperture can provide equal resolution, however. With coude feed optics, spar telescopes can also provide fixed laboratory spaces as tower telescopes do.
This list is incomplete. First we list telescopes with aperture of 50 cm or larger, then some smaller telescopes of interest.
| Name | Type | Ap. | Date | Location |
|---|---|---|---|---|
| Under construction or proposed | ||||
| ATST | RS | 424cm | 2016? | Haleakala |
| BBSO NST | RS | 160cm | 2008 | Big Bear |
| GREGOR | RS | 150cm | 2008 | Tenerife |
| Operational as of November 2007 | ||||
| McMath-Pierce Telescope | ||||
| Main | RT | 150cm | 1962 | Kitt Peak |
| East Auxiliary | RT | 100cm | 1962 | Kitt Peak |
| West Auxiliary | RT | 90cm | 1962 | Kitt Peak |
| SST (Swedish Solar Telescope) | rT | 100cm | 2002 | La Palma |
| Sunrise | Rb | 100cm | 2007 | New Mexico |
| Themis | RT | 90cm | 1996 | Tenerife |
| Crimea | RT | 90cm | 1973 | Crimea, Ukraine |
| Sayan | RT | 80cm | 1979 | Sayan, Russia |
| Baikal LVT | rT | 76cm | 1978 | Lake Baikal, Russia |
| SPO VTT (now Dunn Telescope or DST) | RT | 76cm | 1969 | Sunspot |
| German VTT (Vacuum Tower Telescope) | RT | 70cm | 1987 | Tenerife |
| San Fernando Observatory | RS | 61cm | 1969 | Sylmar |
| Snow telescope | RT | 61cm | 1904 | Mt. Wilson |
| Einsteinturm (Einstein Tower) | rT | 60cm | 1924 | Potsdam, Germany |
| Hida Domeless Solar Telescope | RT | 60cm | 1979 | Takayama, Gifu, Japan |
| Meudon | RT | 60cm | 1968 | Meudon, France |
| Huairou Multi-Channel Telescope | RS | 60cm | 1994 | Huairou, China |
| Crimea coronagraph | cS | 53cm | Crimea, Ukraine | |
| Sayan coronagraph | cS | 53cm | Sayan, Russia | |
| Hinode (Solar-B) | Rs | 50cm | 2006 | low Earth orbit |
| SOLIS VSM (vector magnetograph) | RS | 50cm | 2004 | Kitt Peak |
| Solar-C (off-axis coronagraph) | CS | 50cm | 2001 | Haleakala |
| Yunnan Solar Spectral Telescope | RS | 50cm | Kunming, China | |
| Abastumani coronagraph | cS | 50cm | Abastumani, Georgia | |
| Pic du Midi | rS | 50cm | 1972 | Pic du Midi, France |
| Other solar telescopes of interest | ||||
| SDO HMI | rs | 14cm | 2008 | geosynchronous orbit |
| Dutch Open Telescope (DOT) | RS | 45cm | 1997 | La Palma |
| KIS tower refractor | rT | 45cm | Schauinsland, Germany (nr. Freiburg) | |
| German VNT (Vacuum Newton Telescope) | R | 40cm | Tenerife | |
| Evans Solar Facility (coronagraph) | cS | 40cm | 1953 | Sunspot |
| Marshall SFC | RS | 30cm | Huntsville | |
| TRACE (not visible light) | Rs | 30cm | 1998 | low Earth orbit |
| Mt. Wilson 150-foot tower | rT | 30cm | 1912 | Mt. Wilson |
| Mees IVM (vector magnetograph) | rS | 28cm | 1992 | Haleakala |
| Mees coronagraph | cS | 25cm | Haleakala | |
| Mt. Wilson 60-foot tower | rT | 1907 | Mt. Wilson | |
| SMART | rS | 2x25cm, 2x20cm | 2003 | Hida Observatory, Japan |
| SOHO MDI | rs | 12cm | 1995 | L1 Lagrange point |
| GONG | rT | 3cm | 1995 | Big Bear, Mauna Loa, Learmonth, Udaipur, Tenerife, Cerro Tololo |
| No longer in service | ||||
| Kitt Peak Vacuum Telescope (replaced by SOLIS VSM) | RT | 70cm | 1973 | Kitt Peak |
| BBSO (removed 2006, replaced by NST) | RS | 65cm | 1973 | Big Bear |
| Swedish VTT (Vacuum Tower Telescope, replaced by SST) | rT | 50cm | 1985 | La Palma |
| German GCT (Gregory Coude Telescope, replaced by GREGOR) | R | 45cm | Tenerife | |
| BBSO "10 inch" (removed 2006, replaced by NST) | rS | 25cm | 1970 | Big Bear |
Type:
r = refractor
R = reflector
c = refractor coronagraph
C = reflector coronagraph
b = balloon
s = spacecraft
S = spar (or some other type of pointed telescope)
T = tower (generally a fixed telescope with a heliostat, coelostat, or turret)
For example, RT means a reflecting tower (or other fixed) telescope and Rs means a reflecting telescope on a spacecraft.
u.c. = under construction
U.S. solar telescope locations:
Kitt Peak is in Arizona.
Sunspot is in New Mexico.
Big Bear, Mt. Wilson, and Sylmar are in California.
Haleakala is on the island of Maui in Hawaii.
Mauna Loa is on the island of Hawaii in Hawaii.
Huntsville is in Alabama.
Other popular locations:
La Palma and Tenerife are in the Canary Islands which belong to Spain.
Learmonth is in Australia.
Cerro Tololo is in Chile.
Udaipur is in India.