Apache Point Observatory

Apache Point Observatory

ARCSAT and SDSS telescope buildings at the Apache Point Observatory.
Organization	Astrophysical Research Consortium
Code	705 (APO), 645 (SDSS)
Location	Sunspot, New Mexico
Coordinates	32°46′49″N 105°49′13″W / 32.78028°N 105.82028°WCoordinates: 32°46′49″N 105°49′13″W / 32.78028°N 105.82028°W
Altitude	2,788 meters (9,147 ft)
Weather	65% clear nights
Established	1985
Website	www.apo.nmsu.edu
Telescopes
Astrophysical Research Consortium telescope 3.5 m reflector Sloan Digital Sky Survey telescope 2.5 m reflector New Mexico State University telescope 1.0 m reflector ARCSAT 0.5 m reflector
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The Apache Point Observatory (APO) is an astronomical observatory located in the Sacramento Mountains in Sunspot, New Mexico, United States, approximately 18 miles (29 km) south of Cloudcroft. The observatory is operated by New Mexico State University (NMSU) and owned by the Astrophysical Research Consortium (ARC). Access to the telescopes and buildings is restricted, but the public is able to visit the grounds.^[1]

History

Sunspot Astronomy and Visitor's Center

The ARC was formed in 1984 with the goal of building the 3.5 m telescope. It originally consisted of five institutions: New Mexico State University, University of Washington, University of Chicago, Princeton University, and Washington State University, which has since withdrawn.

Five additional organizations have joined over time: the Institute for Advanced Study, Johns Hopkins University, University of Colorado, University of Virginia, and Georgia State University. Funding for the 3.5 m and 0.5 m telescopes comes from consortium, but funds for the 2.5 m telescope come from a much wider array of sources. The 1.0 m telescope is supported exclusively by NMSU.^[2]

Telescopes

ARC 3.5 m

The ARC 3.5-meter telescope

The ARC 3.5 m (140 in) telescope is a Ritchey-Chretien reflector on an alt-azimuth mount with instruments attached at several focal points. Construction of the building began in 1985, but full operations of the telescope were delayed until November of 1994 due to problems with fabricating the primary mirror.^[3] From 1991 until early 1993 the telescope was fitted with a 1.8 m mirror now located at Rothney Astrophysical Observatory under a cost-sharing agreement.^[4][5]

There are a variety of optical and near-infrared instruments available for the 3.5 m telescope, including:

• The ARC echelle spectrometer (ARCES) uses a 2048 x 2048 pixel CCD and has a resolution of R~31,500.^[6]
• The Double Imaging Spectrometer (DIS) is a low-resolution optical spectrometer.^[7]
• The Near Infrared Camera/Fabry–Pérot Spectrometer (NICFPS) was developed at the University of Colorado. It uses a 1024x1024 H1RG HgCdTe infrared detector and a near-infrared Fabry–Pérot interferometer. It has many narrow band filters, including H2, [Fe II], and [SiVI]. It is unique among astronomical Fabry-Pérot devices in that it is cooled with liquid nitrogen.^[8]
• The Seaver Prototype Imaging camera (SPIcam) is an optical imaging instrument with a 2048x2048 pixel CCD.^[9]
• TripleSpec (Tspec) is a near infrared spectrograph which provides continuous wavelength coverage over the range 0.94-2.46 µm at moderate resolution (R~3500, depending on the choice of slit).^[10]

The 3.5 m telescope is also used by the Apache Point Observatory Lunar Laser-ranging Operation (APOLLO) lunar-ranging project. The APOLLO laser has been operational since October 2005, and routinely accomplishes millimeter-level range accuracy between the Earth and the Moon.^[11][12]

Observations using the 3.5 m telescope can be carried out remotely by observers using TUI, the Telescope User Interface, via the internet.^[13]

SDSS 2.5 m

Enclosure of the SDSS

The SDSS 2.5 m (98 in) telescope is used for the Sloan Digital Sky Survey, and began operating in 2000. It is a Ritchey-Chretien reflector on an alt-azimuth mount housed under a roll-off enclosure. It was designed with an unusually large 3° field of view to better support its primary task of surveying the entire sky.^[14]

NMSU 1.0 m

The NMSU 1.0 m (39 in) telescope is a Ritchey-Chretien reflector set on an alt-azimuth mount, and was completed in 1994.^[15][16] A 2048x2048 CCD mounted at the Nasmyth focus provides at 15.7 arcminute view of the sky.^[17]

0.5 m ARCSAT

The ARC Small Aperture Telescope (ARCSAT) was previously called the Photometric Telescope (PT) when it was part of the SDSS project. It is a 0.5 m (20 in) reflecting telescope on an equatorial mount, with a single CCD camera cooled by a CryoTiger unit.^[18] It was built in 1991, moved from its previous location in 1998, and used by the SDSS until 2005.^[19] It is currently used for small research projects.

Former telescopes

• A 0.6 m (24 in) reflecting telescope was built in 1993 to monitor sky conditions for the SDSS project. It never operated in a satisfactory manner, and was replaced with the 0.5 m PT.^[19]

See also

• List of observatories
• National Solar Observatory

References

1. "Public Access and Tours". Apache Point Observatory. Retrieved 2012-01-07.
2. Holtzman, Jon; et al. (2009-03-15). Apache Point Observatory: Facilities, Operations, and Partnerships. Astro2010: The Astronomy and Astrophysics Decadal Survey (Report) (National Academies). Retrieved 2012-01-14.
3. Peterson, Jim. "A Brief History of the Astrophysical Research Consortium (ARC) and the Apache Point Observatory (APO)". Apache Point Observatory. Retrieved 2012-01-07.
4. "Annual Reports of Astronomical Observatories and Departments: Apache Point Observatory, Astrophysical Research Consortium". Bulletin of the American Astronomical Society 24: 17. 1992. Bibcode:1992BAAS...24...17.
5. York, D. G. (1994). "University of Chicago, Apache Point Observatory/Department of Astronomy and Astrophysics, Chicago, Illinois 60637". Bulletin of the Astronomical Society 26: 58. Bibcode:1994BAAS...26...58Y.
6. "ARC 3.5m | ARCES (Echelle)". Apache Point Observatory. Retrieved 2012-01-07.
7. "ARC 3.5m | DIS". Apache Point Observatory. Retrieved 2012-01-07.
8. "ARC 3.5m | NICFPS". Apache Point Observatory. Retrieved 2012-01-07.
9. "ARC 3.5m | SPIcam". Apache Point Observatory. Retrieved 2012-01-07.
10. "ARC 3.5m | TripleSpec". Apache Point Observatory. Retrieved 2012-01-07.
11. "APOLLO". Apache Point Observatory Lunar Laser-ranging Operation. Retrieved 2012-01-07.
12. Battat, J. B. R.; Murphy, T. W.; Adelberger, E. G.; Gillespie, B.; Hoyle, C. D.; McMillan, R. J.; Michelsen, E. L.; Nordtvedt, K.; Orin, A. E.; Stubbs, C. W.; Swanson, H. E. (1 January 2009). "The Apache Point Observatory Lunar Laser-ranging Operation (APOLLO): Two Years of Millimeter-Precision Measurements of the Earth-Moon Range1". Publications of the Astronomical Society of the Pacific 121 (875): 29–40. Bibcode:2009PASP..121...29B. doi:10.1086/596748.
13. "TUI Telescope User Interface". Apache Point Observatory. Retrieved 2012-01-07.
14. Gunn, James E.; et al. (1 April 2006). "The 2.5 m Telescope of the Sloan Digital Sky Survey". The Astronomical Journal 131 (4): 2332–2359. arXiv:astro-ph/0602326. Bibcode:2006AJ....131.2332G. doi:10.1086/500975.
15. Holtzman, Jon A.; Harrison, Thomas E.; Coughlin, Jeffrey L. (1 January 2010). "The NMSU 1 m Telescope at Apache Point Observatory". Advances in Astronomy 2010: 1–9. Bibcode:2010AdAst2010E..46H. doi:10.1155/2010/193086. Retrieved 2012-01-07.
16. "Annual Reports of Astronomical Observatories and Departments: Astrophysical Research Consortium, Apache Point Observatory". Bulletin of the American Astronomical Society 27: 9. 1995. Bibcode:1995BAAS...27....9.
17. "APO 1m telescope Home Page". Apache Point Observatory. Retrieved 2012-01-07.
18. "Astrophysical Research Consortium Small Aperture Telescope". Apache Point Observatory. Retrieved 2012-01-07.
19. "History of the 20-inch Telescope". Apache Point Observatory. Retrieved 2012-01-07.

External links

• Astronomy Department at NMSU
• Sloan Digital Sky Survey homepage
• Apache Point Clear Sky Clock Forecasts of observing conditions.