Wide Field and Planetary Camera 2

Last updated

Brought back to Earth by the U.S. Space Shuttle, the WFPC is loaded for transport after display at JPL on its way to its final home at the National Air and Space Museum in 2010 Wfpc20101013r.jpg
Brought back to Earth by the U.S. Space Shuttle, the WFPC is loaded for transport after display at JPL on its way to its final home at the National Air and Space Museum in 2010
Quantum efficiency of the CCD chip in the camera Quantum efficiency graph for WFPC2-en.svg
Quantum efficiency of the CCD chip in the camera

The Wide Field and Planetary Camera 2 (WFPC2) is a camera formerly installed on the Hubble Space Telescope. The camera was built by the Jet Propulsion Laboratory and is roughly the size of a baby grand piano. It was installed by servicing mission 1 (STS-61) in 1993, replacing the telescope's original Wide Field and Planetary Camera (WF/PC). WFPC2 was used to image the Hubble Deep Field in 1995, the Engraved Hourglass Nebula and Egg Nebula in 1996, and the Hubble Deep Field South in 1998. During STS-125, WFPC2 was removed and replaced with the Wide Field Camera 3 as part of the mission's first spacewalk on May 14, 2009. After returning to Earth, the camera was displayed briefly at the National Air and Space Museum and the Jet Propulsion Laboratory before returning to its final home at the Smithsonian's National Air and Space Museum. [1] [2]

Contents

Design

WFPC2 was built by NASA's Jet Propulsion Laboratory, which also built the predecessor WFPC camera launched with Hubble in 1990. WFPC2 contains internal corrective optics to fix the spherical aberration in the Hubble telescope's primary mirror.

The charge-coupled devices (CCDs) in the WFPC2 (designed at JPL and manufactured by Loral) detected electromagnetic radiation in a range from 120 nm to 1000 nm. This included the 380 nm to 780 nm of the visible spectrum, all of the near ultraviolet (and a small part of the extreme ultraviolet band) and most of the near-infrared band. The sensitivity distribution of these CCDs is roughly normal, with a peak around 700 nm and concomitantly very poor sensitivity at the extremes of the CCDs' operating range. WFPC2 featured four identical CCD detectors, each 800x800 pixels. Three of these, arranged in an L-formation, comprise Hubble's Wide Field Camera (WFC). Adjacent to them is the Planetary Camera (PC), a fourth CCD with different (narrower-focused) optics. This afforded a more detailed view over a smaller region of the visual field. WFC and PC images are typically combined, producing the WFPC2's characteristic stairstep image. When distributed as non-scientific JPEG files the PC portion of the image is shown with the same resolution as the WFC portions, but astronomers receive a raw scientific image package which presents the PC image in its native, higher detail.

To allow scientists to view specific parts of the electromagnetic spectrum the WFPC2 featured a rotating wheel which moves different optical filters into the lightpath (between the WFPC2's aperture and the CCD detectors). The 48 filter elements included:

Performance

Picture of small section of the Carina Nebula created from images taken with Hubble's Wide Field Planetary Camera 2. Small Section of the Carina Nebula.jpg
Picture of small section of the Carina Nebula created from images taken with Hubble's Wide Field Planetary Camera 2.

As predicted, over the course of its mission the WFPC2 experienced degradation of the CCDs, resulting in defective ("hot") pixels. The telescope's operators performed monthly calibration tests to catalog these; with the WFPC's aperture closed a number of long exposures are taken, and pixels which differ significantly from near black are flagged. To avoid false positives caused by cosmic rays tripping a given pixel, the output of different calibration shots is compared. Pixels which are consistently "hot" are recorded, and astronomers who analyse raw WFPC2 images receive a list of these pixels. Typically, astronomers adjust their photo-processing software to ignore these bad pixels.

WFPC2 was largely superseded for broad-band imaging by the Advanced Camera for Surveys, installed during servicing mission 3B in 2002. However, the early 2007 failure of ACS resulted in WFPC2 returning to its role as Hubble's primary visible light camera. WFPC2 was removed from HST during Servicing Mission 4 in May 2009, for return to Earth and eventual museum display. It was replaced by Wide Field Camera 3, which features two UV/visible detecting CCDs, each 2048x4096 pixels, and a separate IR CCD of 1024 x 1024, capable of receiving infrared radiation up to 1700 nm.

See also

Other HST instruments :

WFPC2 images

Related Research Articles

<span class="mw-page-title-main">Hubble Space Telescope</span> NASA/ESA space telescope launched in 1990

The Hubble Space Telescope is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versatile, renowned both as a vital research tool and as a public relations boon for astronomy. The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories. The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls the spacecraft.

<span class="mw-page-title-main">Hubble Deep Field</span> Multiple exposure image of deep space in the constellation Ursa Major

The Hubble Deep Field (HDF) is an image of a small region in the constellation Ursa Major, constructed from a series of observations by the Hubble Space Telescope. It covers an area about 2.6 arcminutes on a side, about one 24-millionth of the whole sky, which is equivalent in angular size to a tennis ball at a distance of 100 metres. The image was assembled from 342 separate exposures taken with the Space Telescope's Wide Field and Planetary Camera 2 over ten consecutive days between December 18 and 28, 1995.

<span class="mw-page-title-main">STS-61</span> 1993 American crewed spaceflight to the Hubble Space Telescope

STS-61 was the first NASA Hubble Space Telescope servicing mission, and the fifth flight of the Space Shuttle Endeavour. The mission launched on 2 December 1993 from Kennedy Space Center (KSC) in Florida. The mission restored the spaceborne observatory's vision with the installation of a new main camera and a corrective optics package (COSTAR). This correction occurred more than three and a half years after the Hubble was launched aboard STS-31 in April 1990. The flight also brought instrument upgrades and new solar arrays to the telescope.

<span class="mw-page-title-main">Hubble Ultra-Deep Field</span> Deep-field space image

The Hubble Ultra-Deep Field (HUDF) is a deep-field image of a small region of space in the constellation Fornax, containing an estimated 10,000 galaxies. The original data for the image was collected by the Hubble Space Telescope from September 2003 to January 2004. It includes light from galaxies that existed about 13 billion years ago, some 400 to 800 million years after the Big Bang.

<span class="mw-page-title-main">STS-82</span> 1997 American crewed spaceflight to the Hubble Space Telescope

STS-82 was the 22nd flight of the Space Shuttle Discovery and the 82nd mission of the Space Shuttle program. It was NASA's second mission to service the Hubble Space Telescope, during which Discovery's crew repaired and upgraded the telescope's scientific instruments, increasing its research capabilities. Discovery launched from Kennedy Space Center, Florida, on 11 February 1997, returning to Earth on 21 February 1997 at Kennedy Space Center.

<span class="mw-page-title-main">Space Telescope Imaging Spectrograph</span> Instrument on the Hubble Space Telescope

The Space Telescope Imaging Spectrograph (STIS) is a spectrograph, also with a camera mode, installed on the Hubble Space Telescope. Aerospace engineer Bruce Woodgate of the Goddard Space Flight Center was the principal investigator and creator of the STIS. It operated continuously from 1997 until a power supply failure in August 2004. After repairs, it began operating again in 2009. The spectrograph has made many important observations, including the first spectrum of the atmosphere of an extrasolar planet, HD 209458b.

<span class="mw-page-title-main">Near Infrared Camera and Multi-Object Spectrometer</span>

The Near Infrared Camera and Multi-Object Spectrometer (NICMOS) is a scientific instrument for infrared astronomy, installed on the Hubble Space Telescope (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.

<span class="mw-page-title-main">Advanced Camera for Surveys</span> Installed on HST March 2002

The Advanced Camera for Surveys (ACS) is a third-generation axial instrument aboard the Hubble Space Telescope (HST). The initial design and scientific capabilities of ACS were defined by a team based at Johns Hopkins University. ACS was assembled and tested extensively at Ball Aerospace & Technologies Corp. and the Goddard Space Flight Center and underwent a final flight-ready verification at the Kennedy Space Center before integration in the cargo bay of the Columbia orbiter. It was launched on March 1, 2002, as part of Servicing Mission 3B (STS-109) and installed in HST on March 7, replacing the Faint Object Camera (FOC), the last original instrument. ACS cost US$86 million at that time.

<span class="mw-page-title-main">Faint Object Spectrograph</span>

The Faint Object Spectrograph (FOS) was a spectrograph installed on the Hubble Space Telescope. It was replaced by the Space Telescope Imaging Spectrograph in 1997, and is now on display in the National Air and Space Museum in Washington DC.

<span class="mw-page-title-main">Wide Field and Planetary Camera</span> Former instrument on the Hubble Space Telescope

The Wide Field/Planetary Camera (WFPC) was a camera installed on the Hubble Space Telescope launched in April 1990 and operated until December 1993. It was one of the instruments on Hubble at launch, but its functionality was severely impaired by the defects of the main mirror optics which afflicted the telescope. However, it produced uniquely valuable high resolution images of relatively bright astronomical objects, allowing for a number of discoveries to be made by HST even in its aberrated condition.

<span class="mw-page-title-main">Space Telescope European Coordinating Facility</span>

The Space Telescope – European Coordinating Facility (ST-ECF) was an institution which provided a number of support and service functions primarily for European observers of the NASA/ESA Hubble Space Telescope (HST). It was established in 1984 by the European Space Agency (ESA) and the European Southern Observatory (ESO), and was located at the ESO headquarters in Garching bei München, Germany. The ST-ECF ceased operations on 31 December 2010.

<span class="mw-page-title-main">Mercator Telescope</span>

The Mercator Telescope is a 1.2 m telescope at the Observatorio del Roque de Los Muchachos on La Palma. It is operated by the Katholieke Universiteit Leuven, Belgium, in collaboration with the Observatory of the University of Geneva and named after Gerard Mercator, famous cartographer.

<span class="mw-page-title-main">Hubble Deep Field South</span>

The Hubble Deep Field South is a composite of several hundred individual images taken using the Hubble Space Telescope's Wide Field and Planetary Camera 2 over 10 days in September and October 1998. It followed the great success of the original Hubble Deep Field in facilitating the study of extremely distant galaxies in early stages of their evolution. While the WFPC2 took very deep optical images, nearby fields were simultaneously imaged by the Space Telescope Imaging Spectrograph (STIS) and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS).

An association (astronomy) is a combined or co-added group of astronomical exposures from which cosmic rays have been removed. WFPC2 associations constitute one type of association and are tools in the Hubble Space Telescope (HST) archive for using data from the Wide Field and Planetary Camera 2 (WFPC2). Associations were introduced in the HST archive at the beginning of 1998. Since then, astronomers have been able to retrieve on-the-fly re-calibrated co-added WFPC2 images that have already been cleaned of cosmic rays from the Space Telescope European Coordinating Facility (ST-ECF), the Canadian Astronomy Data Centre (CADC) and Space Telescope Science Institute (STScI) archives.

<span class="mw-page-title-main">Corrective Optics Space Telescope Axial Replacement</span>

The Corrective Optics Space Telescope Axial Replacement (COSTAR) is an optical correction instrument designed and built by NASA. It was created to correct the spherical aberration of the Hubble Space Telescope's primary mirror, which incorrectly focused light upon the Faint Object Camera (FOC), Faint Object Spectrograph (FOS), and Goddard High Resolution Spectrograph (GHRS) instruments.

<span class="mw-page-title-main">Cosmic Origins Spectrograph</span>

The Cosmic Origins Spectrograph (COS) is a science instrument that was installed on the Hubble Space Telescope during Servicing Mission 4 (STS-125) in May 2009. It is designed for ultraviolet (90–320 nm) spectroscopy of faint point sources with a resolving power of ≈1,550–24,000. Science goals include the study of the origins of large scale structure in the universe, the formation and evolution of galaxies, and the origin of stellar and planetary systems and the cold interstellar medium. COS was developed and built by the Center for Astrophysics and Space Astronomy (CASA-ARL) at the University of Colorado at Boulder and the Ball Aerospace and Technologies Corporation in Boulder, Colorado.

<i>Pillars of Creation</i> Astrophotograph by the Hubble Space Telescope

Pillars of Creation is a photograph taken by the Hubble Space Telescope of elephant trunks of interstellar gas and dust in the Eagle Nebula, in the Serpens constellation, some 6,500–7,000 light-years from Earth. They are named so because the gas and dust are in the process of creating new stars, while also being eroded by the light from nearby stars that have recently formed. Taken on April 1, 1995, it was named one of the top ten photographs from Hubble by Space.com. The astronomers responsible for the photo were Jeff Hester and Paul Scowen from Arizona State University. The region was rephotographed by ESA's Herschel Space Observatory in 2011, again by Hubble in 2014 with a newer camera, and the James Webb Space Telescope in 2022.

<span class="mw-page-title-main">Southern Crab Nebula</span> Planetary nebula in the constellation Centaurus

The Southern Crab Nebula is a nebula in the constellation Centaurus. The nebula is several thousand light years from Earth, and its central star is a symbiotic Mira variable - white dwarf pair. It is named for its resemblance to the Crab Nebula, which is in the northern sky.

<span class="mw-page-title-main">Wide Field Camera 3</span>

The Wide Field Camera 3 (WFC3) is the Hubble Space Telescope's last and most technologically advanced instrument to take images in the visible spectrum. It was installed as a replacement for the Wide Field and Planetary Camera 2 during the first spacewalk of Space Shuttle mission STS-125 on May 14, 2009.

<span class="mw-page-title-main">NIRSpec</span> Spectrograph on the James Webb Space Telescope

The NIRSpec is one of the four scientific instruments flown on the James Webb Space Telescope (JWST). The JWST is the follow-on mission to the Hubble Space Telescope (HST) and is developed to receive more information about the origins of the universe by observing infrared light from the first stars and galaxies. In comparison to HST, its instruments will allow looking further back in time and will study the so-called Dark Ages during which the universe was opaque, about 150 to 800 million years after the Big Bang.

References

  1. ""The Camera that Saved Hubble" Coming to the Smithsonian". May 27, 2009. Retrieved July 14, 2009.
  2. "The Camera That Saved Hubble Leaves the Nest". JPL / NASA. Retrieved October 14, 2010.
  3. "Return to the Carina Nebula". ESA/Hubble Picture of the Week. ESA/Hubble. Retrieved July 4, 2011.