The Near Infrared Camera and Multi-Object Spectrometer (NICMOS) is a scientific instrument

Measuring instrument

In the physical sciences, quality assurance, and engineering, measurement is the activity of obtaining and comparing physical quantities of real-world objects and events. Established standard objects and events are used as units, and the process of measurement gives a number relating the item...

 for infrared astronomy

Infrared astronomy

Infrared astronomy is the branch of astronomy and astrophysics that studies astronomical objects visible in infrared radiation. The wavelength of infrared light ranges from 0.75 to 300 micrometers...

, installed on the Hubble Space Telescope

Hubble Space Telescope

The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...

 (HST), operating from 1997 to 1999, and from 2002 to 2008. Images produced by NICMOS contain data from the near-infrared part of the light spectrum (it can see heat), colors correspond to the longer wavelengths.

NICMOS was conceived and designed by the NICMOS Instrument Definition Team centered at Steward Observatory

Steward Observatory

The University of Arizona's Steward Observatorys main office is located on the University's campus and is closely tied to the Department of Astronomy. Established in 1916 by its first director, Andrew Ellicott Douglass, and a $60,000 bequest made by Lavinia Steward in memory of her late husband...

, University of Arizona

University of Arizona

The University of Arizona is a land-grant and space-grant public institution of higher education and research located in Tucson, Arizona, United States. The University of Arizona was the first university in the state of Arizona, founded in 1885...

, USA. NICMOS is an imager and spectrometer built by Ball Aerospace & Technologies Corp. that allows the HST to observe infrared light, with wavelength

Wavelength

In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...

s between 0.8 and 2.4 micrometers, providing imaging and slitless spectrophotometric capabilities. NICMOS contains three near-infrared detectors in three optical channels providing high (~ 0.1 arcsecond) resolution, coronagraphic and polarimetric imaging, and slitless spectroscopy in 11, 19, and 52 arcsecond square fields of view. Each optical channel contains a 256×256 pixel photodiode array of Hg_0.554Cd_0.446Te infrared detector

Infrared detector

An infrared detector is a photodetector that reacts to infrared radiation. The two main types of detectors are thermal and photonic.The thermal effects of the incident IR radiation can be followed through many temperature dependent phenomena....

s bonded to a sapphire substrate, read out in four independent 128×128 quadrants.

The infrared performance of the Hubble has limitations since it was not designed with infrared performance as an objective. For example, the mirror is kept at a stable and relatively high temperature (15 C) by heaters.

“HST is a warm telescope. The IR background flux collected by cooled focal plane IR instruments like
NICMOS or WFC3 is dominated, at rather short wavelengths, by telescope thermal emission rather than by zodiacal scattering. NICMOS data show that the telescope background exceeds the zodiacal background at wavelengths longer than λ ≈ 1.6μm, the exact value depending on the pointing on the sky and on the position of the Earth on its orbit.”

NICMOS was installed on Hubble during its second servicing mission in 1997 along with the Space Telescope Imaging Spectrograph

Space Telescope Imaging Spectrograph

The Space Telescope Imaging Spectrograph is a spectrograph, also with a camera mode, installed on the Hubble Space Telescope. It operated continuously from 1997 until a power supply failure in 2004. After repairs, it began operating again in 2009...

, replacing two earlier instruments. NICMOS in turn has been largely superseded by the Wide Field Camera 3

Wide Field Camera 3

The Wide Field Camera 3 is the Hubble Space Telescope's last and most technologically advanced instrument to take images in the visible spectrum...

, which has a much larger field of view (135 by 127 arcsec, or 2.3 by 2.1 arcminutes), and reaches almost as far into the infrared.

When conducting infrared measurements, it is necessary to keep the infrared detectors cooled to avoid having infrared interference from the instrument's own thermal emissions. NICMOS contains a cryogenic dewar

Dewar flask

A Dewar flask is a vessel designed to provide very good thermal insulation. For instance, when filled with a hot liquid, the vessel will not allow the heat to easily escape, and the liquid will stay hot for far longer than in a typical container...

, that cooled its detectors to ~ 61 K, and optical filters to ~ 105 K, with a block of solid nitrogen

Nitrogen

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

 ice. When NICMOS was installed in 1997, the dewar flask

Dewar flask

A Dewar flask is a vessel designed to provide very good thermal insulation. For instance, when filled with a hot liquid, the vessel will not allow the heat to easily escape, and the liquid will stay hot for far longer than in a typical container...

 contained a 230 pound (104 kg) block of nitrogen ice. Due to a thermal short that arose on March 4, 1997 during the instrument commissioning, the dewar ran out of nitrogen coolant sooner than expected in January, 1999. During Hubble Service Mission 3B in 2002, a cryocooler

Cryocooler

Cryocoolers are the devices used to reach cryogenic temperatures by cycling certain gases.A cryostat is likely to be used to reach and/or maintain similar conditions or keep some environment in cryogenic stasis...

 and external radiator were installed on the Hubble that now cools NICMOS through a cryogenic neon

Neon

Neon is the chemical element that has the symbol Ne and an atomic number of 10. Although a very common element in the universe, it is rare on Earth. A colorless, inert noble gas under standard conditions, neon gives a distinct reddish-orange glow when used in either low-voltage neon glow lamps or...

 loop. NICMOS was returned to service soon after SM 3B.

A new software upload in Sept. 2008 necessitated a brief shutdown of the NICMOS cryocooler. Several attempts to restart the cooler failed. After waiting more than 6 weeks for the instrument to warm up, and theorized ice particles to evaporate from the cooling system, the cooler once again
failed to restart. A successful restart at 13:30 EST on 16 December 2008 led to four days of cooler operations followed by another shutdown. On August 1, 2009, the cooler was restarted again. NICMOS was expected to resume operations mid February 2010.
On June 18, 2010, it was announced NICMOS will not be available for science during the latest proposal Cycle 18. A decision as to whether NICMOS will be available for science in the future has not been made yet.

NICMOS is also the name of the devices's 256×256 pixel imaging sensor developed by Rockwell

Rockwell

- People :* Dick Rockwell, an American comic strip and comic book artist, nephew of Norman Rockwell* Francis W. Rockwell, a United States Congressman from Massachusetts* Francis W...

 International Science Center (now Teledyne

Teledyne

Teledyne Technologies Incorporated is an industrial conglomerate primarily based in the United States but with global operations. It was founded in 1960, as Teledyne, Inc., by Henry Singleton and George Kozmetsky....

 Imaging Sensors).

In 2009, an old NICMOS image was processed to show a predicted exoplanet around the star HR 8799

HR 8799

HR 8799 is a young main sequence star located 129 light years away from Earth in the constellation of Pegasus, with roughly 1.5 times the Sun's mass and 4.9 times its luminosity. It is part of a system that also contains a debris disk and at least four massive planets...

. The system is thought to be about 130 light-years from Earth.

In 2011, around that same star, four exoplanets were rendered viewable in a NICMOS image taken in 1998, using advanced data processing. The exoplanets were originally discovered with the Keck telescopes and the Gemini North telescope between 2007 and 2010. The image allows the orbits of the exoplanets to analyzed more closely, since they take many decades, even hundreds of Earth years to orbit their host star.

External links

• NICMOS at ESA/Hubble
• Images taken with NICMOS at ESA/Hubble
• Technical information from Steward Observatory
  Steward Observatory
  The University of Arizona's Steward Observatorys main office is located on the University's campus and is closely tied to the Department of Astronomy. Established in 1916 by its first director, Andrew Ellicott Douglass, and a $60,000 bequest made by Lavinia Steward in memory of her late husband...
  
  's instrument team
• NICMOS sensor family