GSU Magazine: In the Line of Fire
Astronomy
Astronomy
Georgia State University operates the Center for High Angular Resolution Astronomy, or CHARA, at Mount Wilson, California. In 2009, one of the largest wildfires in the history of Los Angeles County came perilously close to a facility responsible for unique images of our universe. This feature for the Winter 2010 edition of GSU Magazine tells the story of the observatory and the efforts made to save it from destruction.
In the peaks of the San Gabriel Mountains overlooking the smog and streetscapes of metropolitan Los Angeles, the winding Angeles Crest Highway leads to one of the most notable locations in the history of astronomy, the Mount Wilson Observatory.
It’s where many fundamentals of modern astronomy were first observed. It’s where Edwin Hubble showed that our Milky Way galaxy is just one of many galaxies, all rushing away from one another in a vast universe.
It’s also where the sun’s magnetic field was discovered, and where astronomer Walter Baade determined that all stars were not born at the same time.
And today it’s where Georgia State University, one of several institutions operating on the site, is leading stellar exploration with its six-telescope Center for High Angular Resolution Astronomy Array.
But the past and the present of astronomy at the mountain were imperiled late last summer by the massive Station Fire — later deemed arson by authorities — which came perilously close to the observatory and threatened to damage or destroy its vital equipment.
Thanks to the tireless efforts of fire crews from across the country who beat back the flames, the site was saved. This is a story of their efforts, and of the science they preserved and protected, allowing researchers from Georgia State and elsewhere to continue working to better understand our galaxy and our universe.
A Charred Landscape
The observatory atop Mount Wilson is located on a peak more than a mile above sea level. In late October of 2009, the Angeles Crest Highway, which leads to the peak and is a National Scenic Byway used by many commuters from desert towns north of the mountains to reach Los Angeles, was still closed to the general public, and for good reason.
The guard rails, whose wooden supports had been incinerated by the flames as they jumped across the tight, hairpin curves, were still under repair. Rains had brought mud flows, as much of the vegetation holding the ground in place had been destroyed. Fallen rocks — not quite boulders, but of a size that could puncture tires — littered the road.
Only those working on the mountain or who had a legitimate reason to be there could obtain a permit from the California Department of Transportation to traverse the highway.
Driving from the suburb of La Cañada Flintridge at the foot of the mountains, they would see the green palms of manicured lawns give way to a rocky landscape more closely resembling the barren surfaces of the moon or Mars dotted with the charred remnants of fir trees and chaparral.
Ascending farther up the mountain, however, the desolate, lonely landscape eventually transitions to a greener scene. With the exception of brown trees that had been stressed, but not burned, by the fire, the firs, pines and sequoias still stand high, as do the white domes of the observatory’s 100-inch and 60-inch telescopes, along with the six telescopes of Georgia State’s CHARA Array.
The survival of this arboreal refuge was hard won.
Danger Unfolds
California wildfires are nothing new. The Santa Ana winds blowing hot air from the Mojave Desert, combined with low humidity, create a perfect recipe for fire — fire, which to be fair, is part of the life cycle of southern California’s ecosystem.
But the Station Fire — one of the worst in Los Angeles County history — was started by a human.
Dave Jurasevich, superintendent at the Mount Wilson Observatory, remembers the day the Station Fire started, when it started, and where — events that would launch a wholesale effort to avert disaster.
“Wednesday, Aug. 26, at 3:20 p.m., in the forest, two and a half miles north of La Cañada,” recalled Jurasevich. “I’ll never forget the time. I was apprised of the situation and knew that it had started, but never in my wildest dreams did I think that it was going to reach Mount Wilson.”
By the following day, he and others realized that the fire was out of control — the flames would eventually come within a half mile of the CHARA array — and a mandatory evacuation of the observatory was called.
Larry Webster, site manager for the CHARA facilities, and Jake Hodge, assistant superintendent, remained on the mountain to coordinate evacuation. Meanwhile, Hal McAlister, CHARA’s director, director and CEO of the Mount Wilson Institute, and a Georgia State Regents’ Professor of astronomy, nervously followed the situation back in Atlanta.
He kept a blog on the Mount Wilson Observatory Web site and updated it as soon as news reached him — some of it encouraging, some of it not.
The fire became so intense and so close to the mountaintop and the vulnerable CHARA Array, that Jurasevich, Webster and Hodge were told on Aug. 31 to leave via a circuitous route down and around the mountain. They would not be able to return for 24 hours.
“It was the worst 24 hours of the entire incident, because I simply did not know what was happening on the ground,” Jurasevich said.
McAlister, who has devoted much of his academic life to making CHARA a reality, heard about the worsening situation from Jurasevich while driving into work to teach his 10 a.m. class.
“Dave called me and told me what was happening, and I was just dumbfounded because the firefighters had told Dave that they could fight the fire and defend it,” McAlister said. “At 9:30, I got to school. For the first time ever, I couldn’t teach my class. I just told my students, ‘I’m sorry, I’m not up to this.’ I could hardly speak. That was really the worst.”
Hotshots
The flames came a little less than three football fields away from the CHARA Array, filling the air with thick, acrid smoke and intense heat. If the winds changed direction, the blaze would run over the top of the mountain in a matter of minutes, incinerating the CHARA Array and causing serious damage to the old, historic telescope domes.
The firefighters had to think quickly and strategically to adapt as the fire inched closer and closer. Hundreds of them came and went, risking their lives as they furiously set up firelines to rob the fire of the fuel it needed to move farther toward the mountain’s peak.
Tanker planes dumped red Phos-Chek fire retardant onto the fire’s pathway (left) while backfires were set to ensure that leaves, pine needles and other fuel wouldn’t start to blaze from within the firelines.
Among the many firefighting units on the scene — including the California Department of Forestry and Fire Protection and the L.A. County and City fire departments — were the federal “Hotshot” crews.
The Interagency Hotshots consist of crews from the U.S. Forest Service, the Bureau of Land Management, the National Park Service and a number of Native American tribes, which work together to fight wildfires in the United States and Canada. One of the crews that fought the blaze at Mount Wilson was from Helena, Mont. This crew, the Helena Hotshots, with 18 men and five women, spent 15 days at the mountain assessing the facilities, performing preparation work, putting in firelines and clearing brush through backfires, said Fred Thompson, the team’s superintendent.
To reduce the amount of flammable materials and to keep the flames from coming back, the crews set controlled fires down a 75 to 80 degree angle ridge.
“It’s steep, hazardous terrain,” Thompson explained.
He and the other team leaders choose only the most qualified and able for the long, exhausting work, which sometimes requires carrying equipment that weighs up to 70 pounds.
“It takes a special sort of individual who can take that kind of punishment,” Thompson said. “But it’s a great job, and those of us who enjoy it like the physical and mental challenge.”
Wildfires are nothing out of the ordinary for the Helena Hotshots, but the Mount Wilson fire was unique for Thompson, a 17-year veteran firefighter with seven years as a Hotshot.
“When you’ve got something historic and a major site in science, it adds a certain amount of urgency,” he said. “It’s good to be a part of that. You feel that you’re making a difference. This was a monumental assignment in my career.”
Thanks to the Hotshots’ efforts — and those of all of the firefighters who risked their lives on the mountains to contain the blaze — neither the CHARA Array nor the observatory suffered major damage. And none of the firefighters on Mount Wilson suffered injuries.
“Those firefighters are just awesome,” Jurasevich said. “You’ve heard it all before from people who’ve been through fires, and it might sound trite, ‘What heroes those firefighters are,’ but I can tell you unequivocally that these guys are the true heroes of this event.”
Cleaning Up, Continuing Science
By October, some semblance of normalcy had returned to Mount Wilson. The wildlife had returned, too. Hawks could be heard echoing through the canyons, and mountain lions and bears came back to the thick, forested environs.
Operations at the observatory also came back to life, but slowly. Just as the CHARA Array had to be shut down in a proper sequence before evacuation, they had to be returned to function in a corresponding sequence.
“Whenever you turn the array off for a few weeks at a time, it’s like a sleepy kid,” McAlister explained. “It doesn’t want to wake up and get dressed for school.”
In the meantime, the grounds around the CHARA Array’s telescopes and other infrastructure were mostly repaired and cleaned up; the fire retardant — described as slime by Theo ten Brummelaar, associate director of CHARA — was removed from the grounds, and the T1 Internet line, a vital link to the outside world that had been severed due to a faulty, melted pull box, was back in good shape.
Finally, researchers and staff from Georgia State, UCLA and the University of California, Berkeley were able to resume some of the scientific operations at the observatory, though nearly five weeks of observing time had been lost because of the fire.
On a cool October night in the CHARA control room, Gail Schaefer, a California-based post-doctoral researcher from GSU, and P.J. Goldfinger, a telescope array operator, sat along with Russel White, a GSU professor of astronomy visiting the observatory, as six screens showed the vitals of the array as they homed in on the stars.
Schafer and Goldfinger watched with anticipation as the array’s calibration focused and wavy lines appeared on the monitor.
“We’ve got fringes!” Schaefer exclaimed.
To create these “fringes,” the array uses interferometry to make high resolution observations to determine astrophysical properties of stars, such as diameter, temperature, distance, energy output and mass, with incredible precision.
For example, in 2006, from similar data, scientists with Georgia State and the University of Michigan snapped a picture of the star Altair — the first detailed image of a hydrogen-burning star other than our sun. Other firsts at the CHARA array include the direct detection of gravity darkening on a single star, Regulus; the first model-independent measurement of the diameter of a planet outside our solar system; and the first direct image of an interacting binary star system, Beta Lyrae.
Even though operations have resumed, the Station Fire will continue to affect the observatory for years to come. Mount Wilson personnel and astronomers are accustomed to dealing with pollen, dust and fallen ashes from minor fires in the Angeles National Forest every year, McAlister explained, but the six telescopes will have to be cleaned more often than usual of the ash stirred from the Station Fire, and the array will need to be shut down for short periods during the cleaning.
And when the rainy season comes, bringing with it the increased likelihood of rock and mud slides due to the fire, access to the observatory could shut off for days or weeks at a time.
“We’ve never been subject to being surrounded by an ashen wasteland like this,” McAlister said.
On the Web
Hal McAlister kept a well-documented blog about the Station Fire and its threat to the observatory. It includes links to Jurasevich’s photography, as well as links to videos filmed by Susan McAlister, available at http://www.mtwilson.edu/fire.php.
More about the CHARA array and the Center for High Angular Resolution Astronomy is available at http://www.chara.gsu.edu/CHARA.
It’s where many fundamentals of modern astronomy were first observed. It’s where Edwin Hubble showed that our Milky Way galaxy is just one of many galaxies, all rushing away from one another in a vast universe.
It’s also where the sun’s magnetic field was discovered, and where astronomer Walter Baade determined that all stars were not born at the same time.
And today it’s where Georgia State University, one of several institutions operating on the site, is leading stellar exploration with its six-telescope Center for High Angular Resolution Astronomy Array.
But the past and the present of astronomy at the mountain were imperiled late last summer by the massive Station Fire — later deemed arson by authorities — which came perilously close to the observatory and threatened to damage or destroy its vital equipment.
Thanks to the tireless efforts of fire crews from across the country who beat back the flames, the site was saved. This is a story of their efforts, and of the science they preserved and protected, allowing researchers from Georgia State and elsewhere to continue working to better understand our galaxy and our universe.
A Charred Landscape
The observatory atop Mount Wilson is located on a peak more than a mile above sea level. In late October of 2009, the Angeles Crest Highway, which leads to the peak and is a National Scenic Byway used by many commuters from desert towns north of the mountains to reach Los Angeles, was still closed to the general public, and for good reason.
The guard rails, whose wooden supports had been incinerated by the flames as they jumped across the tight, hairpin curves, were still under repair. Rains had brought mud flows, as much of the vegetation holding the ground in place had been destroyed. Fallen rocks — not quite boulders, but of a size that could puncture tires — littered the road.
Only those working on the mountain or who had a legitimate reason to be there could obtain a permit from the California Department of Transportation to traverse the highway.
Driving from the suburb of La Cañada Flintridge at the foot of the mountains, they would see the green palms of manicured lawns give way to a rocky landscape more closely resembling the barren surfaces of the moon or Mars dotted with the charred remnants of fir trees and chaparral.
Ascending farther up the mountain, however, the desolate, lonely landscape eventually transitions to a greener scene. With the exception of brown trees that had been stressed, but not burned, by the fire, the firs, pines and sequoias still stand high, as do the white domes of the observatory’s 100-inch and 60-inch telescopes, along with the six telescopes of Georgia State’s CHARA Array.
The survival of this arboreal refuge was hard won.
Danger Unfolds
California wildfires are nothing new. The Santa Ana winds blowing hot air from the Mojave Desert, combined with low humidity, create a perfect recipe for fire — fire, which to be fair, is part of the life cycle of southern California’s ecosystem.
But the Station Fire — one of the worst in Los Angeles County history — was started by a human.
Dave Jurasevich, superintendent at the Mount Wilson Observatory, remembers the day the Station Fire started, when it started, and where — events that would launch a wholesale effort to avert disaster.
“Wednesday, Aug. 26, at 3:20 p.m., in the forest, two and a half miles north of La Cañada,” recalled Jurasevich. “I’ll never forget the time. I was apprised of the situation and knew that it had started, but never in my wildest dreams did I think that it was going to reach Mount Wilson.”
By the following day, he and others realized that the fire was out of control — the flames would eventually come within a half mile of the CHARA array — and a mandatory evacuation of the observatory was called.
Larry Webster, site manager for the CHARA facilities, and Jake Hodge, assistant superintendent, remained on the mountain to coordinate evacuation. Meanwhile, Hal McAlister, CHARA’s director, director and CEO of the Mount Wilson Institute, and a Georgia State Regents’ Professor of astronomy, nervously followed the situation back in Atlanta.
He kept a blog on the Mount Wilson Observatory Web site and updated it as soon as news reached him — some of it encouraging, some of it not.
The fire became so intense and so close to the mountaintop and the vulnerable CHARA Array, that Jurasevich, Webster and Hodge were told on Aug. 31 to leave via a circuitous route down and around the mountain. They would not be able to return for 24 hours.
“It was the worst 24 hours of the entire incident, because I simply did not know what was happening on the ground,” Jurasevich said.
McAlister, who has devoted much of his academic life to making CHARA a reality, heard about the worsening situation from Jurasevich while driving into work to teach his 10 a.m. class.
“Dave called me and told me what was happening, and I was just dumbfounded because the firefighters had told Dave that they could fight the fire and defend it,” McAlister said. “At 9:30, I got to school. For the first time ever, I couldn’t teach my class. I just told my students, ‘I’m sorry, I’m not up to this.’ I could hardly speak. That was really the worst.”
Hotshots
The flames came a little less than three football fields away from the CHARA Array, filling the air with thick, acrid smoke and intense heat. If the winds changed direction, the blaze would run over the top of the mountain in a matter of minutes, incinerating the CHARA Array and causing serious damage to the old, historic telescope domes.
The firefighters had to think quickly and strategically to adapt as the fire inched closer and closer. Hundreds of them came and went, risking their lives as they furiously set up firelines to rob the fire of the fuel it needed to move farther toward the mountain’s peak.
Tanker planes dumped red Phos-Chek fire retardant onto the fire’s pathway (left) while backfires were set to ensure that leaves, pine needles and other fuel wouldn’t start to blaze from within the firelines.
Among the many firefighting units on the scene — including the California Department of Forestry and Fire Protection and the L.A. County and City fire departments — were the federal “Hotshot” crews.
The Interagency Hotshots consist of crews from the U.S. Forest Service, the Bureau of Land Management, the National Park Service and a number of Native American tribes, which work together to fight wildfires in the United States and Canada. One of the crews that fought the blaze at Mount Wilson was from Helena, Mont. This crew, the Helena Hotshots, with 18 men and five women, spent 15 days at the mountain assessing the facilities, performing preparation work, putting in firelines and clearing brush through backfires, said Fred Thompson, the team’s superintendent.
To reduce the amount of flammable materials and to keep the flames from coming back, the crews set controlled fires down a 75 to 80 degree angle ridge.
“It’s steep, hazardous terrain,” Thompson explained.
He and the other team leaders choose only the most qualified and able for the long, exhausting work, which sometimes requires carrying equipment that weighs up to 70 pounds.
“It takes a special sort of individual who can take that kind of punishment,” Thompson said. “But it’s a great job, and those of us who enjoy it like the physical and mental challenge.”
Wildfires are nothing out of the ordinary for the Helena Hotshots, but the Mount Wilson fire was unique for Thompson, a 17-year veteran firefighter with seven years as a Hotshot.
“When you’ve got something historic and a major site in science, it adds a certain amount of urgency,” he said. “It’s good to be a part of that. You feel that you’re making a difference. This was a monumental assignment in my career.”
Thanks to the Hotshots’ efforts — and those of all of the firefighters who risked their lives on the mountains to contain the blaze — neither the CHARA Array nor the observatory suffered major damage. And none of the firefighters on Mount Wilson suffered injuries.
“Those firefighters are just awesome,” Jurasevich said. “You’ve heard it all before from people who’ve been through fires, and it might sound trite, ‘What heroes those firefighters are,’ but I can tell you unequivocally that these guys are the true heroes of this event.”
Cleaning Up, Continuing Science
By October, some semblance of normalcy had returned to Mount Wilson. The wildlife had returned, too. Hawks could be heard echoing through the canyons, and mountain lions and bears came back to the thick, forested environs.
Operations at the observatory also came back to life, but slowly. Just as the CHARA Array had to be shut down in a proper sequence before evacuation, they had to be returned to function in a corresponding sequence.
“Whenever you turn the array off for a few weeks at a time, it’s like a sleepy kid,” McAlister explained. “It doesn’t want to wake up and get dressed for school.”
In the meantime, the grounds around the CHARA Array’s telescopes and other infrastructure were mostly repaired and cleaned up; the fire retardant — described as slime by Theo ten Brummelaar, associate director of CHARA — was removed from the grounds, and the T1 Internet line, a vital link to the outside world that had been severed due to a faulty, melted pull box, was back in good shape.
Finally, researchers and staff from Georgia State, UCLA and the University of California, Berkeley were able to resume some of the scientific operations at the observatory, though nearly five weeks of observing time had been lost because of the fire.
On a cool October night in the CHARA control room, Gail Schaefer, a California-based post-doctoral researcher from GSU, and P.J. Goldfinger, a telescope array operator, sat along with Russel White, a GSU professor of astronomy visiting the observatory, as six screens showed the vitals of the array as they homed in on the stars.
Schafer and Goldfinger watched with anticipation as the array’s calibration focused and wavy lines appeared on the monitor.
“We’ve got fringes!” Schaefer exclaimed.
To create these “fringes,” the array uses interferometry to make high resolution observations to determine astrophysical properties of stars, such as diameter, temperature, distance, energy output and mass, with incredible precision.
For example, in 2006, from similar data, scientists with Georgia State and the University of Michigan snapped a picture of the star Altair — the first detailed image of a hydrogen-burning star other than our sun. Other firsts at the CHARA array include the direct detection of gravity darkening on a single star, Regulus; the first model-independent measurement of the diameter of a planet outside our solar system; and the first direct image of an interacting binary star system, Beta Lyrae.
Even though operations have resumed, the Station Fire will continue to affect the observatory for years to come. Mount Wilson personnel and astronomers are accustomed to dealing with pollen, dust and fallen ashes from minor fires in the Angeles National Forest every year, McAlister explained, but the six telescopes will have to be cleaned more often than usual of the ash stirred from the Station Fire, and the array will need to be shut down for short periods during the cleaning.
And when the rainy season comes, bringing with it the increased likelihood of rock and mud slides due to the fire, access to the observatory could shut off for days or weeks at a time.
“We’ve never been subject to being surrounded by an ashen wasteland like this,” McAlister said.
On the Web
Hal McAlister kept a well-documented blog about the Station Fire and its threat to the observatory. It includes links to Jurasevich’s photography, as well as links to videos filmed by Susan McAlister, available at http://www.mtwilson.edu/fire.php.
More about the CHARA array and the Center for High Angular Resolution Astronomy is available at http://www.chara.gsu.edu/CHARA.