In September and October 1998, WFPC2
imaged the Deep Field South, in Tucana, which was simultaneously observed by the Space Telescope Imaging Spectrograph (STIS) and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS).
The earlier WFPC2
observation, however, showed a 6-to-1 ratio of dark matter to normal matter, which challenged theories of how dark matter behaves.
Credits for WFPC2
image: NASA, the Hubble Heritage Team (STScI/AURA) and ESA
Clicking the advanced-search hot-linked text allows you to specify the observing instrument (ACS, WFPC2
, WFC3, etc.), spectral elements, and so on.
instrument, which was installed in 1993 to replace the original Wide Field/Planetary Camera, will be removed to make room for Wide Field Camera 3 during the upcoming Hubble Servicing Mission.
The ACS took over the role of workhorse camera from WFPC2
following its installation in 2002.
Next year's servicing mission will replace WFPC2
with the Wide Field Camera 3 (WFC3), which will have excellent near-infrared capability but won't be as good as ACS was in the visual band.
APEX): [12.sup.h] [36.sup.m] [49.4.sup.s], +62[degrees] 12' 58" (2000.0)
With more than twice the imaging area of WFPC2
, three times the sensitivity, and slightly higher resolution as well, it can be considered 10 times as efficient per frame.
More important, the Wide Field Camera should record up to 44 percent of the photons that strike Hubble's 2.4-meter-diameter (94.5-inch) primary mirror, a threefold improvement over the WFPC2
's 14.5 percent.
Krist (Space Telescope Science Institute), Stapelfeldt, and their colleagues on the WFPC2
science team detail the finding in the July 10th Astrophysical Journal.
But the image that appears at left (and graced the cover of Newsweek's November 3rd issue) was acquired with WFPC2
, the replacement wide-field camera that compensates for the primary mirror's spherical aberration.