Wide Field Camera 3

Wide Field Camera 3
Name	Wide Field Camera 3
Caption	WFC3 being prepared for installation on the Hubble Space Telescope during STS-125.
Operator	NASA / ESA
Manufacturer	Goddard Space Flight Center
Type	CCD / Infrared camera
Website	https://www.nasa.gov/mission_pages/hubble/servicing/SM4/wfc3.html

Wide Field Camera 3. It is a fourth-generation scientific instrument installed on the Hubble Space Telescope during Servicing Mission 4 in 2009. Designed as a versatile workhorse camera, it replaced the Wide Field and Planetary Camera 2 and significantly enhanced Hubble's imaging capabilities across ultraviolet, visible, and near-infrared wavelengths. Its development was led by a team at NASA's Goddard Space Flight Center.

Overview

Wide Field Camera 3 serves as the primary panchromatic imaging instrument aboard the Hubble Space Telescope, offering a complementary suite of channels to other onboard instruments like the Advanced Camera for Surveys. It features two independent light paths: a ultraviolet and visible (UVIS) channel utilizing silicon charge-coupled device technology and a near-infrared (IR) channel employing a mercury-cadmium-telluride detector. This dual-channel design allows astronomers to observe phenomena ranging from nearby Solar System objects to the most distant galaxies in the early universe. The instrument's wide field of view and high sensitivity have made it indispensable for large-scale surveys and detailed follow-up observations.

Development and launch

The concept for WFC3 emerged in the late 1990s following the cancellation of a planned instrument during the Hubble Space Telescope development. After the Columbia disaster in 2003, its installation became a central objective of the final servicing mission. The project was managed by NASA's Goddard Space Flight Center, with significant contributions from the Space Telescope Science Institute and industrial partners like Ball Aerospace & Technologies. It was successfully launched aboard the Space Shuttle Atlantis on mission STS-125 in May 2009, where astronauts performed a complex series of spacewalks to install it, along with other instruments like the Cosmic Origins Spectrograph.

Technical specifications

The ultraviolet/visible channel employs two 2051 x 4096 pixel charge-coupled devices, providing a field of view of 164 by 164 arcseconds and sensitivity from 200 to 1000 nanometers. The near-infrared channel uses a 1014 x 1014 pixel HgCdTe detector, sensitive from 800 to 1700 nanometers, with a field of view of 123 by 137 arcseconds. Key optical elements include a selection of 62 filters, grisms, and a quartz corrective optics element. The instrument's data is processed and calibrated by teams at the Space Telescope Science Institute in Baltimore.

Scientific capabilities and modes

WFC3 operates in several distinct modes tailored for specific astronomical investigations. Direct imaging is its most common mode, utilizing a broad array of spectral filters to study stellar populations, nebulae, and galaxy morphology. The near-infrared channel is particularly adept at peering through cosmic dust in regions like the Orion Nebula and the center of the Milky Way. Its slitless spectroscopy mode, using grisms, allows for efficient surveys of exoplanet atmospheres and distant quasars. Specialized modes also support precise astrometry and time-series photometry for studying variable stars and transiting planets.

Key discoveries and contributions

WFC3 has been pivotal in numerous landmark studies. It provided deep infrared images for the Hubble Ultra-Deep Field, revealing some of the most distant galaxies ever observed, such as GN-z11. The camera was instrumental in characterizing the atmospheres of exoplanets in systems like TRAPPIST-1 and WASP-121b. It has captured detailed views of Solar System bodies, including the impact of Comet Shoemaker–Levy 9 on Jupiter and seasonal changes on Mars and Saturn. WFC3 data also contributed to measuring the expansion rate of the universe, refining the value of the Hubble constant.

Status and legacy

As of 2024, Wide Field Camera 3 remains in full scientific operation aboard the Hubble Space Telescope, continuing to produce a high volume of peer-reviewed research. Its robust design has ensured remarkable longevity with minimal degradation in performance. The instrument's legacy is cemented by its role in training a generation of astronomers and by the vast public archive of iconic images it has produced. WFC3's success directly informed the design of cameras for the James Webb Space Telescope and future observatories like the Nancy Grace Roman Space Telescope, ensuring its technological influence will extend for decades.

Category:Hubble Space Telescope instruments Category:Space cameras Category:NASA spacecraft instruments