Thursday, August 26, 1999

SAO Chandra X-Ray Center and NASA
Cassiopeia A is the remnant of a star that exploded about 300
years ago. This gaseous shell is about 10 light years in diameter
and has a temperature of 50 million degrees.

Chandra telescope
sends first images

UH astronomers have $1 million-plus
in grants to use the observatory

By Helen Altonn


There were times in the past 22 years when University of Hawaii physics and astronomy professor J. Patrick Henry wondered if it would really happen.

Today it did: the unveiling of the first pictures from NASA's powerful Chandra X-ray Observatory, showing spectacular remnants of a supernova and other astronomical phenomena.

Henry said he was "a very junior member" of the 1977 proposal that led to the orbiting telescope's development, led by the Smithsonian Astrophysical Observatory in Cambridge, Mass.

"One of the reasons I came to Hawaii was, I could just see it was going to take 20 years before this thing flew," he said.

He joined the UH Institute for Astronomy in 1981, and now has one of about four Chandra Science Center branches across the country.

Henry and his colleagues have more than $1 million in NASA grants to use the X-ray observatory for studies into the structure and evolution of the universe.

"We have a fairly big Chandra involvement," said Henry. "We're all waiting anxiously to see the kind of data we will get."

By Ken Ige, Star-Bulletin
Next to a poster of the Chandra X-ray Observatory are
Chandra Science Center members J. Patrick Henry,
front, and, from left, Harald Ebeling, Doug Burke,
Isabella Gioia, Christopher Mullis and Amy Barger.

Chandra has been undergoing a checkout since it was placed into Earth orbit during the space shuttle mission last month.

The observatory is in an elliptical orbit that reaches about one-third of the way to the moon at its high point, making it too high for a shuttle to go up and fix it.

Consequently, there is much hope that Chandra does not have a problem with focus, Henry said, noting that whenever the Hubble Space Telescope is mentioned, people think of its initial "out of focus" problems.

NASA -- operating Chandra from its Marshall Space Flight Center in Huntsville, Ala. -- describes the new space telescope as a laboratory on the universe that "cannot be replicated here on Earth."

It is a "time machine" that can study quasars as they were 10 billion years ago, NASA says. It will see exploding stars, black holes, colliding galaxies and other high-energy cosmic objects.

Henry says Chandra is complementary to the Hubble telescope.

"It sees very violent, extreme events in the universe, where Hubble sees more sedate things -- normal stars and normal galaxies," he said. "X-rays come from violent, hot places in the universe."

Other UH astronomers involved with the Chandra mission include Doug Burke, Harald Ebeling, Amy Barger and Isabella Gioia, a visiting astronomer from the Instituto de Radio Astronomia in Italy. Ebeling has the largest single block of Chandra observing time outside of the people who built the instrument, Henry said. "It is quite a coup for him."

This image of NASA's Chandra X-ray Observatory
following deployment from the Space Shuttle Columbia
was taken from High Definition Television.

He said Barger is a Chandra fellow, one of about a dozen in the United States. "It is a very prestigious award." The Chandra program pays the recipient's salary for three years, he said.

Barger also is a Hubble fellow, "the only person I know who won both awards at the same time," Henry said. Her program is to combine Chandra observations with those from the Big Island's Mauna Kea Observatory, he said.

The other institute astronomers involved are interested in clusters of galaxies, Henry said. "Galaxies, like the Milky Way, tend to come in groups, in clusters, and these clusters are very, very strong in X-rays," he said.

"There is, in fact, more material making X-rays in these clusters than there are in galaxies," he said. "A better name for these things would be X-ray spheres."

Much more can be learned about these clusters by looking at their X-rays than by using traditional optical telescopes, Henry said.

"What we're particularly interested in is, how do these clusters change with time? This gives you a good idea how the universe itself changes with time.

"We're studying the structure and evolution of the universe using the evolution of these clusters of galaxies."

Henry said the Chandra mission has cost about $1.5 billion, and an estimated $1 billion will be spent over the telescope's life. It's designed to operate five years, he said, "and everybody hopes it will go longer than that."

Several hundred astronomers around the world are scheduled to use the Chandra for observations, Henry said.

Since he's been associated with it at some level for 22 years, Henry said he is "pretty anxious" to start receiving data.

He wondered at times if the project would survive because "there were threats early on to cancel the whole thing," he recalled.

Congress required Chandra demonstrate its capabilities by a certain date or it would stop funding the mission, he said.

"So there were both technical and financial challenges," he said. "You wouldn't bet that it would get canceled. But you wouldn't bet a whole lot that it wouldn't be."

All about Chandra

The Chandra X-ray Observatory:

Bullet Has eight times greater resolution and is able to detect sources more than 20 times fainter than any earlier X-ray telescope.
Bullet Is about one billion times more powerful than the first X-ray telescope.
Bullet Was the largest and heaviest payload ever launched by the space shuttle.
Bullet Has an orbit that will take it 200 times higher than the Hubble Space Telescope. During each orbit of the Earth, it will travel one-third of the way to the moon.
Bullet Has a resolving power equal to the ability to read the letters of a stop sign at a distance of 12 miles.
Bullet Will observe X-rays from clouds of gas so vast that it takes light more than 5 million years to go from one side to another.
Bullet Will be able to study particles up to the last millisecond before they are sucked into a black hole.

Source: NASA

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