Transcript WFPC2

The Workhorse of the
Hubble Space Telescope for
15 years!
•WFPC is pronounced
“wif pic ”!
•WFPC 2 was installed during
Hubble’s 1st Servicing Mission,
in December of 1993
•WFPC 2 replaced the original
WFPC, and contained corrective
optics to compensate for the
spherical aberration caused by
the flawed main mirror
•WFPC 2 remained in orbit for
15 years, until replaced by
WFPC 3 in May of 2009
WFPC 2 consists of 4 individual cameras…
3 Wide Field Cameras, and 1 high
resolution Planetary Camera. They could be
used individually, or together, creating this
“stairstep” pattern.
Each camera is a CCD detector with
800x800 pixels.
48 Filters were available to study a
wide range of wavelengths.
WFPC 2 was able
to see wavelengths
from UV to near IR.
Light Path into the Hubble
Optical Telescope Assemby
(OTA).
Light Path within WFPC 2.
The light beam from the
OTA travels through the
chosen filter, then to the
Fold Mirror, Primary Mirror,
and Secondary Mirror.
Then to the CCD Detector.
WFPC-2
FGS = Fine Guidance Sensor (used for pointing)
The placement of the
instruments after each
servicing mission.
The WFPC cameras are
“radial” and are directly in
the path of the main
optics.
The other instruments are
“axial”, and sit to the side
of the optical path.
Each instrument accesses
a different part of the
incoming light beam.
•
The radiator attached to WFPC2 has dimensions of 2.2 m by 0.8 m.
•
Its outermost layer is a 4-mm-thick aluminum, curved plate coated with white
thermal paint.
•
This radiator has been exposed to space since the deployment of WFPC2 in 1993.
•
Due to its large surface area and long exposure time, the radiator serves as a
unique witness plate for the micrometeoroid and orbital debris (MMOD) environment
between 560 and 620 km altitude.
Size of
Hubble’s Orbit
~350
miles
above
surface
Size of
Earth’s
Atmosphere
~60 miles
above
surface
Hubble orbits
Earth every
90 minutes
Raw data from the
WFPC contains
cosmic rays and the
instrument’s electronic
“noise”.
Data Processing
removes the flaws and
combines exposures
to create a clean
image.
Red, Green, and Blue
filtered images can be
combined to create a
final color image.
“WFPC 2’s Greatest Hits”
The Images that Changed our
View of the Universe…
These images of M100 show the dramatic improvement in capability after the 1st
Servicing Mission.
The WFPC-1 image on the left shows the effect of the spherical aberration in the mirror.
The optics in WFPC-2 compensated for the flaw, giving us unprecedented clarity!
The Hubble Deep Field
What happens when you stare at a relatively blank piece of
sky for 10 days straight? Hubble Astronomers asked this
question in 1995, as here’s what we found out…
That small speck of sky
contains over 1000 galaxies,
each with hundreds of
thousands of stars!
Our world got a lot smaller…
Eagle Nebula
A Close-up of part of this nebula
revealed a “stellar nursery”.
Each point of light jutting out from
these gas pillars is a star in the
process of formation.
In 1994, Comet Shoemaker-Levy 9 was
discovered to be on a collision course with Jupiter.
It broke into several small pieces and slammed
into Jupiter over the course of several days.
It was a rare opportunity to watch a planetary
impact event!
Before Hubble, astronomers
suspected, but had no proof,
that supermassive black holes
lurk deep in the bellies of
galaxies.
WFPC2 image of a spiral-shaped disk of hot gas
in the core of active galaxy M87. HST
measurements show the disk is rotating so
rapidly it contains a massive black hole at its hub.
The Wide Field and Planetary
Camera 2, together with
spectroscopy data from
Hubble, showed that most
galaxies in the universe do
indeed harbor monstrous
black holes up to billions of
times the mass of our sun.
Our universe began in a colossal expansion known as the Big Bang, and has been stretching apart ever since.
Using WFPC2 to observe stars that vary periodically in brightness, astronomers were able to calculate the pace
of this expansion to an unprecedented degree of error of 10 percent.
The camera also played a leading role in discovering that the expansion of the universe is accelerating, driven
by a mysterious force called “dark energy.” Together, these findings led to the calculation that our universe is
approximately 13.7 billion years old.
A huge, billowing pair of gas and dust clouds is captured in this stunning image
of the super-massive star Eta Carinae.
Eta Carinae is expected to go supernova in the (relatively) near future.
The left-most galaxy, or the "one" in
this image, is relatively undisturbed
apart from a smooth ring of starlight. It
appears nearly on edge to our line of
sight. The right-most galaxy,
resembling a zero, exhibits a clumpy,
blue ring of intense star formation.
These galaxies appear to make a perfect
“10” – showing that Hubble was in prime
form after being off-line.
WFPC2 caught a cosmic dance between two spiral galaxies. Strong gravitational
forces from NGC 2207 have distorted the shape of its smaller dance partner,
flinging out stars and gas into long streamers that extend 100,000 light-years toward
the right-hand edge of the picture. Eventually this dance will end. Billions of years
from now the two galaxies will become one.
Mercury is too close to the Sun to be observed by Hubble
Saturn
Jupiter
Uranus
Neptune
In tribute to Hubble's longest running optical camera, a planetary nebula,
Kohoutek 4-55, has been imaged as WFPC2's final "pretty picture".
In May of 2009, WFPC 2 was removed from the Hubble Space Telescope, and
replaced with the WFPC3.
WFPC 2’s new permanent home is the Smithsonian Air and Space Museum