Apache Point Observatory

Apache Point Observatory

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The Apache Point Observatory (APO) is located in the Sacramento Mountains
Sacramento Mountains
The Sacramento Mountains are a mountain range in the south-central part of the U.S. state of New Mexico, lying just east of Alamogordo in Otero County...

 in Sunspot
Sunspot, New Mexico
Sunspot is an unincorporated community in the Sacramento Mountains in Otero County, New Mexico, United States. It is located within the Lincoln National Forest, 18 miles south of Cloudcroft. Its elevation is 9200 feet....

, New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

 (USA) 18 miles south of Cloudcroft
Cloudcroft, New Mexico
Cloudcroft is a village in Otero County, New Mexico and is within the Lincoln National Forest. The population was 749 at the 2000 census. Despite being located in an otherwise arid region, its extremely high elevation allows for a relatively mild summer that makes it a popular tourist attraction...

. The observatory
Observatory
An observatory is a location used for observing terrestrial or celestial events. Astronomy, climatology/meteorology, geology, oceanography and volcanology are examples of disciplines for which observatories have been constructed...

 consists of the Astrophysical Research Consortium's (ARC) 3.5-meter telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...

, the Sloan Digital Sky Survey
Sloan Digital Sky Survey
The Sloan Digital Sky Survey or SDSS is a major multi-filter imaging and spectroscopic redshift survey using a dedicated 2.5-m wide-angle optical telescope at Apache Point Observatory in New Mexico, United States. The project was named after the Alfred P...

 2.5-m telescope with a 20" photometric telescope, and New Mexico State University's
New Mexico State University
New Mexico State University at Las Cruces , is a major land-grant university in Las Cruces, New Mexico, United States...

 1.0-m telescope. Access to the telescopes and buildings is restricted, but the public is welcomed to stroll the grounds. The visitor's center at Sun Spot (the National Solar Observatory
National Solar Observatory
The mission of the National Solar Observatory is to advance knowledge of the Sun, both as an astronomical object and as the dominant external influence on Earth, by providing forefront observational opportunities to the research community...

) includes a model of Apache Point's 3.5 meter telescope and actual filter plates for the Sloan telescope.

The 3.5 m telescope hosts the APOLLO
Apache Point Observatory Lunar Laser-ranging Operation
The Apache Point Observatory Lunar Laser-ranging Operation, or APOLLO, is a project at the Apache Point Observatory in New Mexico. It is an extension and advancement of previous Lunar Laser Ranging Experiment, which uses retroreflectors on the Moon to track changes in lunar orbital distance and...

 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.

Observations at APO are often carried out remotely by observers using TUI, the Telescope User Interface, via the internet.

NICFPS


The Near Infrared Camera/Fabry–Pérot Spectrometer was developed at the University of Colorado
University of Colorado at Boulder
The University of Colorado Boulder is a public research university located in Boulder, Colorado...

. It uses a 1024x1024 H1RG HgCdTe infrared detector and a near-infrared Fabry–Pérot interferometer. It has many narrow band filters, including H2
Molecular cloud
A molecular cloud, sometimes called a stellar nursery if star formation is occurring within, is a type of interstellar cloud whose density and size permits the formation of molecules, most commonly molecular hydrogen ....

, [Fe II], and [SiVI]. It is unique among astronomical Fabry-Perot devices in that it is cooled with liquid nitrogen
Liquid nitrogen
Liquid nitrogen is nitrogen in a liquid state at a very low temperature. It is produced industrially by fractional distillation of liquid air. Liquid nitrogen is a colourless clear liquid with density of 0.807 g/mL at its boiling point and a dielectric constant of 1.4...

.

Echelle


The echelle spectrometer
Echelle grating
An echelle grating is a type of diffraction grating which is characterised by a relatively low groove density but is optimized for high diffraction orders. Echelle gratings are, like other types of diffraction grating, used in spectrometers and similar instruments, such as HARPS, and numerous...

 at APO uses a 2048 x 2048 pixel CCD
Charge-coupled device
A charge-coupled device is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time...

 and has a resolution
Spectral resolution
The spectral resolution of a spectrograph, or, more generally, of a frequency spectrum, is a measure of its ability to resolve features in the electromagnetic spectrum...

 of 30,000.

SPIcam


The Seaver Prototype Imaging camera is an optical imaging instrument with a 2048x2048 pixel CCD.

TripleSpec


TripleSpec is a near infrared spectrograph which provides continuous wavelength coverage over the range 0.94-2.46 microns at moderate resolution (R~3500, depending on the choice of slit).

Photometric telescope


The Photometric Telescope, or PT, is an (usually) automated telescope used by the Sloan Digital Sky Survey
Sloan Digital Sky Survey
The Sloan Digital Sky Survey or SDSS is a major multi-filter imaging and spectroscopic redshift survey using a dedicated 2.5-m wide-angle optical telescope at Apache Point Observatory in New Mexico, United States. The project was named after the Alfred P...

 (SDSS). The telescope is a 20" reflector telescope with a single CCD camera, cooled by a CryoTiger unit.

During normal operations of the SDSS 2.5m telescope the PT is under automated control. While the SDSS obtains photometric or spectroscopic data, the PT will image patches of the sky that lie along the drift paths of the SDSS. These patches are used to calibrate the SDSS data, correcting for nightly atmospheric extinction as well as calibrating the data to the ugriz photometric system zero points. This process is required because while the ugriz system is tied to USNO standard stars, the SDSS cannot image directly these stars because they are too bright. Instead the PT records transfer patches which are compared to SDSS data.

The PT uses u'g'r'i'z filters. These filters were intended to be identical to the SDSS ugriz, however physical differences do exist. Works is ongoing to accurately tie the PT to the SDSS, which is important for the future use of SDSS.

See also

  • List of observatories, including a nearby solar observatory
    National Solar Observatory
    The mission of the National Solar Observatory is to advance knowledge of the Sun, both as an astronomical object and as the dominant external influence on Earth, by providing forefront observational opportunities to the research community...


External links