Press release: STScI-PR94-01
Picture perfect: Hubble's new improved optics probe the core of
a distant galaxy
This comparison image of the core of the galaxy M100 shows the
dramatic improvement in Hubble Space Telescope's view of the
universe. The new image was taken with the second generation
Wide Field and Planetary Camera (WFPC-2) which was installed
during the STS-61 Hubble Servicing Mission. The picture
beautifully demonstrates that the corrective optics incorporated
within the WFPC-2 compensate fully for optical aberration in
Hubble's primary mirror. The new camera will allow Hubble to
probe the universe with unprecedented clarity and sensitivity,
and to fulfill many of the most important scientific objectives
for which the telescope was originally built.
Right
The core of the grand design spiral galaxy M100, as imaged by
Hubble Space Telescope's Wide Field Planetary Camera 2 in its
high resolution channel. The WFPC-2 contains modified optics
that correct for Hubble's previously blurry vision, allowing the
telescope for the first time to cleanly resolve faint structure
as small as 30 light-years across in a galaxy which is tens of
millions of light years away. The image was taken on December
31, 1993.
Left
For comparison, a picture taken with the WFPC-1 camera in wide
field mode, on November 27, 1993, just a few days prior to the
STS-61 servicing mission. The effects of optical aberration in
HST's 2.4-meter primary mirror blur starlight, smear out fine
detail, and limit the telescope's ability to see faint structure.
Both Hubble images are "raw;" they have not been subject to
computer image reconstruction techniques commonly used in
aberrated images made before the servicing mission.
Targer information: M100
The galaxy M100 (100th object in the Messier Catalog of
non-stellar objects) is one of the brightest members of the Virgo
Cluster of galaxies. The galaxy is in the spring constellation
Coma Berenices and can be seen through a moderate-sized amateur
telescope. M100 is spiral shaped, like our Milky Way, and tilted
nearly face-on as seen from earth. The galaxy has two prominent
arms of bright stars and several fainter arms. Though the galaxy
is estimated to be tens of millions of light-years away, Hubble
reveals the sort of detail only seen previously (with ground
based telescopes) in neighboring galaxies that are ten times
closer. Before HST, astronomers could only see such a level of
detail in roughly a dozen galaxies in our Local Group. Now, with
Hubble's improved vision, the portion of the universe which can
be studied with such clarity has grown a thousand fold. Only the
future will tell what revelations await as Hubble's spectacular
vision is applied to a host of fascinating and important
questions about the universe and our place in it.
<=== deep-sky objects
Jos van Geffen --
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last modified: 8 March 2000