Transcript The Hubble Mission: Past and Future

The Hubble Mission:
Past and Future
With thanks to NASA for images!
The
most
famous
?
Creating the Hubble Space Telescope
• 1918 – Astronomers Hubble
and Slipher measure
distances and velocities of
galaxies.
– Pioneered the idea of other
galaxies and an expanding
universe
• 1923 – German scientist
Hermann Oberth suggests
the idea of launching a
telescope into space
• 1945 – Astrophysicist Lyman
Spitzer proposes an orbiting
space observatory
Creating the
Hubble Space Telescope
• 1977 – Congress approves
funding for a space telescope
• 1981 – Creation of the STScI
• mid-1980s – Telescope
named after astronomer
Edwin Hubble
– Created Hubble’s Law,
proposed expansion of the
universe
• 1990 – Hubble is launched
– Cost at launch: $1.5 billion
What Does it Do?
• Since 1993, Hubble has:*
– taken over 330,000 separate
observations
– observed more than 25,000 targets
– gathered > 7.3 terabytes of data
– traveled 1.489 billion miles
– provided data for over 2,663 scientific
papers
Orbits 600 km (375 mi)
above the Earth
*according to the
NASA website
Specifications
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•
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Precision pointing
control system
– Checks for
movement 40
times a second,
and slowly adjust
the gyro speeds
to stabilize
pointing
Before
After
Active Galactic Nucleus
Primary mirror 2.4 m
Secondary 0.3 m
Ultra-low expansion glass
COSTAR corrects spherical aberration
17 Years of Hubble:
Top 10 Discoveries
• The Great Comet
Crash
• Extrasolar Planets
• Death Throes
• Cosmic Birthing
• Galactic Archaeology
Mario Livio
Scientific American (2006)
• Supermassive Black
Holes
• The Largest
Explosions
• The Edge of Space
• The Age of the
Universe
• The Accelerating
Universe
The propagation of
waves outward from
the impact site
suggests Jupiter is
oxygen-rich. Is it?
The Great Comet Crash
Extrasolar Planets
• A transiting planet
• 30% lighter than
Jupiter
• 30% larger in diameter
• Bloated by the heat of
its nearby sun?
– P=3.5d, 0.05 AU
– 1580 F!
• No rings or massive
moons
• Atmosphere contains
Na, C, and O
• Evaporating hydrogen
gives a comet-like tail
Births of
Stars
Eagle Nebula M16
• Interstellar gas
surrounds young
stars about to
emerge
• 7,000 light years
• One of the top ten
Hubble images
Natal Disks and Jets
Star Birth
Cluster
• The Lynx Arc
• Biggest, brightest,
hottest star
forming region
ever seen
• 12 billion light
years away
• Stars as hot as
140,000 K
• >1,000,000 hot,
massive, bluewhite stars (Orion
has only 4!)
• Seen through a
gravitational lens
Death Throes I –
SN 1987a
• February 23, 1987
• Large Magellanic Cloud
• The rings are a remnant of
gas ejected by the star a
few tens of thousands of
years ago
• 1987 was a star with an
initial mass of about 18 x
the Sun’s mass
• by the time it exploded, it
was down to about 12 x
the Sun’s mass because of
mass loss
Crab Pulsar
• Combining
Hubble and
Chandra
Observatory
data
• Matter and
antimatter are
being
accelerated to
near the
speed of light
by the pulsar,
a rapidly
spinning
neutron star
Death Throes II – The Death of
Sun-like Stars
• Planetary nebula form when
stars eject their outer
envelops into space,
revealing the hot dense
core at the center of the
star
• Radiation from the exposed
hot core heats the escaping
gas until it glows
• The beautiful shapes are
thought to be caused by
interactions with companion
stars
Stellar
Archaeology
• Finding the faintest
stars in the globular
cluster NGC 6397
• White dwarfs and
red dwarfs
• 8500 LY distant
Ancient Star Cluster M80 = NGC 6093
• One of the densest
star clusters in the
Milky Way
– About 28,000 light
years
– Held together by
mutual gravity
• Stars are basically
the same age, but
have different
masses
• Red giants, blue
helium-burning
stars
Supermassive
Black Holes
The Largest
Explosions
• A gamma-ray burst detected on 21 November 2001 by satellite
• Hubble followed the fading optical counterpart from Dec. 4, 2001, to
May 5, 2002
• At least some of the mysterious cosmic gamma-ray bursts are
produced in the violent event which ends the lives of massive stars
• These stars end in rapidly spinning black holes
• Other types of gamma ray bursts may arise from the merger of two
neutron stars
The
Edge of
Space
The Hubble
Ultra-Deep
Field
The deepest optical sky image ever taken: Faint red smudges may well be
members of the first class of galaxies formed when the universe was only a few
percent of its present age. These faint galaxies are dwarf galaxies from which larger
modern galaxies must have formed.
The Age
of the
Universe
•
•
•
•
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NGC 4603’s distance is determined from 36 Cepheid variables
The period of pulsation of the Cepheids is related to their brightness, and allows
a measurement of the distance – 108 million light years
Observations like these tell us the Hubble Constant, the relation between the
distances to galaxies and their recession velocities.
A Hubble Constant of 70 km s-1 Mpc-1 means a galaxy should appear to recede
160,000 miles per hour faster for every 3.3 million light-year increase in
distance
Measuring the Hubble Constant was a major goal for Hubble
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•
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Brightness measurements of distant, ancient supernovae indicate that expansion
of the universe began to speed up four to six billion years ago, when the Dark
Energy's repulsive force began to overcome the attractive force of gravity over
cosmic distances
Supernovae measured with Hubble hint that Dark Energy's repulsive force is
constant over cosmic time and so could be consistent with Einstein's original
theory of gravitation
If the force actually changes with time, the Universe could still end in a Big
Crunch or a Big Rip ... but not for at least an estimated 30 billion years
Other Hubble
Contributions
• Scientific Productivity – 7% of astronomy papers world-wide
are from Hubble
• The Hubble Archive – Half of the science papers each year
from Hubble utilize archive data rather than new
observations
• Hubble Legacy Program
• Education and Public Outreach
Hubble Deep Field
• RA 12h 36m 49s DEC +62d 13'
(J2000)
• about 1’ square (1/30 of full Moon)
• 150 orbits
• Key Science Results
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–
Small Galaxies in the Early Universe
Open versus Closed Universe
Disturbed Galaxies
Stellar Baby Boom
In Search of Hidden Stars
Missing Mass -- Still Missing
DSS Image:
Hubble Today –
Crippled, but Still Productive
• Problems
– Two instruments
failed
• STIS
• ACS
– Batteries failing
– Gyros failing
(operating with
two)
• Still working
instruments
– FGS
– WFPC2
– NICMOS
Working
Instruments NICMOS
• Near Infrared Camera and Multi Object
Spectometer (0.8-2.5 microns)
– imaging capabilities in broad, medium, and narrow
band filters
– broad-band imaging polarimetry
– coronographic imaging
– slitless grism spectroscopy
• Installed in 1997
Working
Instruments
- WFPC2
• Wide Field and Planetary Camera 2
–
–
–
–
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High resolution images
wide field of view
1150 to 11,000 Å
3 800x800 pixel CCDs + PC
2.5’ x 2.5’
• Installed 1993, optics to correct…
Working Instruments - FGS
• Part of the HST Pointing Control
System (PCS)
• Provides precision astrometry
• Milli-arc second resolution over a
wide range of magnitudes
(3 < V < 16.8)
• Parallax and proper motion of
astrometric targets to a precision of
0.2 mas
• Detect duplicity or structure around
targets as close as 8 mas
• Visual orbits can be determined for
binaries as close as 12 mas
• Effectiveness limited by 2-gyro
operation
Space Telescope
Imaging
Spectrograph
• Installed in 1997
• Spectra and images at ultraviolet and visible wavelengths,
probing the Universe from our solar system out to
cosmological distances
X STIS stopped science operations in August 2004 due to a
failed power supply
• Possible repair during Servicing Mission 4
Advanced
Camera for
Surveys
X Wide Field Channel (WFC) with a field of view of
202x202 square arcsec covering the range from 3700 to
11000 Å and a plate-scale of 0.05 arcsec/pixel
X a High Resolution Channel (HRC), with a field of view of
26x29 square arcsec covering the range from 2000 to
11000 Å and a plate-scale of 0.027 arcsec/pixel
 a Solar Blind Channel (SBC), with a field of view of
31x35 square arcsec, spanning the range from 1150 to
1700 Å and a plate-scale of 0.032 arcsec/pixel
Servicing Hubble
• Servicing Mission 1 – December 1993
– Installation of WFPC2 and COSTAR
(Corrective Optics Space Telescope Axial Replacement)
• Service Mission 2 – February 1997
– new instruments - NICMOS and STIS
• Servicing Mission 3a – November 1999
– new gyros! (+ other infrastructure)
• Servicing Mission 3b – March 2002
– New camera (ACS), restored NICMOS
Servicing Mission 4
• Scheduled for 9/11/2008
• What will be done?
– Install new instruments
• Cosmic Origins Spectrograph
• Wide Field Camera 3
– Repair STIS and/or ACS
– Refurbish Fine Guidance Sensor 3
– Gyros, batteries, thermal blankets
• Extend Hubble’s operating life to 2013
Servicing Mission 4
Cosmic Origins Spectrograph
• Ultraviolet spectrograph
• Trace the large-scale structure of the
Universe
• Trace the composition of gas in distant
galaxies
WFPC3
• Star formation histories of nearby galaxies
• Probing dark energy
• Near UV through optical to near IR
Infrastructure Refurbishment
• FGS
– Two are currently degrading
– One will be replaced
• Gyroscopes
– Hubble designed to use three of six
– Four are currently working, two in use
– Six new gyros will last until 2013
• Batteries
– Original batteries to be replaced to restore power
margins
• New Thermal Blanket (original degraded over
time)
Instrument Repairs
• STIS
– replace an electronics board
– best effort basis – too many
screws!
• ACS – Still not certain what to fix
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Cause of electrical short?
Any collateral damage?
Concepts for repair?
How much EVA time needed?
What else couldn’t be done if ACS is
fixed?
After 2013?
The James Webb Space Telescope
JWST Specs
• 6.2 meter primary
• Observations from 0.6 – 28 microns
JWST to be stationed at L2
• Infrared observations from faint and very distant objects
• The telescope and its instruments must be very cold (T < 50 K (370 deg F))
• A large shield blocks the light from the Sun, Earth, and Moon, which
otherwise would heat up the telescope, and interfere with the
observations
• Must keep Sun, Earth, and Moon in the same direction, behind the
heat shield
WHY JWST?
• First Light - JWST will try to confirm theories about the
early universe by finding and studying the "first light"
objects.
• Assembly of Galaxies - JWST will observe the small,
early building blocks of galaxies in order to understand
how they grow and evolve.
• Birth of Stars and Protoplanetary Systems JWST will examine the birth and early evolution of stars
and their planetary systems.
• Planetary Systems and the Origins of Life JWST will investigate the physical and chemical
properties of planetary systems — including our own —
and try to determine the potential for the origins of life
in those systems.
Sources:
www.hubblesite.org
www.stsci.edu/hst
hubble.nasa.gov
www.jwst.nasa.gov
IU Astronomy listserve:
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