UNC student astronomers use remote technology to touch the stars
Posted December 23, 2016
Chapel Hill, N.C. — It’s 8:30 p.m. on a Wednesday night. The University of North Carolina at Chapel Hill is quiet. Classrooms are empty; doors are locked. A few faint stars peek out from behind thick clouds. In a small room in Chapman Hall, two students have just sat down to begin their work. Projected on the wall are a series of graphs, diagrams and data, all accompanying an impressive image of a large, white star surrounded by hundreds more. A monitor in the corner streams live footage from a telescope control room in northern Chile. On the screen, a mustached man wearing glasses and headphones whistles to himself. Behind him on yet another monitor, fans explode with excitement after a soccer star scores a goal for his team.
From the top of Cerro Pachón, more than 4,500 miles from Chapel Hill, an endless sea of mountains expands in every direction. The vast, desert landscape is otherworldly with its rocky, Mars-like terrain. The sinking sun blankets the region with an orange glow, and its rays glint off large metal domes – giant telescopes that dot the surrounding mountaintops.
There are two telescopes here on Cerro Pachón and another underway, eight across the valley on top of Cerro Tololo and, deeper in the desert, dozens more.
As the sun drops below the horizon, the first glittery stars emerge in the cobalt sky. Soon, millions will burn through the darkness and, once again, ignite a curiosity that has captivated people for thousands of years.
Indigenous peoples of Latin America studied the stars long before the European influence of modern astronomy reached the New World. They memorized the changing constellations and planetary rotations to track time. Long ago, the southern sky was so clear the Incas could pinpoint what they called “dark constellations,” the black undulating formations found in the sparkling band of the Milky Way. The night sky once revered by the Incas has since been tarnished with light pollution emanating from the modern world. Today, that age-old, heavenly scene is visible only from the heights of the Atacama Desert in northern Chile.
Listed by National Geographic as the number one stargazing spot on the planet, the Atacama has drawn astronomers from around the globe and is home to some of the world’s most powerful telescopes. Here, a pristine view of the southern sky reveals cosmos unseen from the Northern Hemisphere. Each year, the dry desert air offers more than 200 clear nights, and there are some places in the Atacama where rainfall hasn’t been recorded in more than 500 years. These conditions, along with minimal pollution, make the Atacama Desert a prime location for major international research telescopes.
Observatories started to crop up in the Atacama in the 1960s when modern astronomy began to flourish. Today, the Cerro Tololo Inter-American Observatory, or CTIO, includes seven telescopes on two adjacent mountains, Cerro Tololo and Cerro Pachón. Headquartered in the nearby coastal city of La Serena, CTIO was one of the first major observatories in Chile.
The largest CTIO structure is the Víctor Blanco 4m Telescope, built in 1974. Although it stands at nearly twice the size of CTIO’s Southern Astrophysical Research Telescope, known as SOAR, it’s no more powerful than its shrunken counterpart. That’s because workers built SOAR nearly 30 years after Blanco, the same 30-year stretch that saw a transformation from large, clunky desktop computers to portable laptops. Technology had changed drastically, and the “bigger and better” mentality was on its way out.
Size, however, isn’t the only thing that’s changed.
Patricio Ugarte, observer support at SOAR since 2003, strokes his white mustache as he thinks back to his days working at Blanco. “When I arrived at Tololo, we didn’t have telephones. The only way to communicate to La Serena was through a radio station. When my first son was born, I knew it two days after because my wife had to send a telegram,” he said. “In the 70s, you needed to work in the darkness – on the platform, attaching the telescope, feeling the weather, the cold in the night.”
Today, Ugarte sits in a room lined with computer screens. A camera connects him to astronomers in other parts of world and, at the touch of a button, he can move the telescope without ever leaving his seat.
Ugarte, in his old age, appreciates the convenience of today’s astrotechnology. “Now, you can work inside of this building. There’s a heater in the winter, you can use the web, you can watch the news. Now, you can go outside, take a look at the sky. You can go to the kitchen to make tea. You know, you can make a lot of things. I have Netflix so I can see some movies,” he said.
However, some astronomers miss the adventure of the old days.
Dr. Wayne Christiansen and his colleague Bruce Carney, who at the time were the only two researching astronomers in the astronomy department at UNC-Chapel Hill, proposed the creation of SOAR in 1986. Although remote observing was one of the futuristic features that helped sell the telescope to wary donors 30 years ago, Christiansen prefers to observe in person.
“I mean, you don’t need to be there,” Christiansen said. “But, emotionally, if you will, it’s not the same. It’s not the same as going on that pilgrimage to the mountain and going out on the mountaintop and seeing the sky and saying, ‘I’m doing something big here.’”
Ugarte agreed, but said although modern technology might weed out some of the exciting challenges that marked the old days of astronomy, it comes with the potential to take astronomers to places they’ve never imagined.
“The old astronomy was more romantic because you saw with your eyes, you touched with your hands. It’s more impersonal [now],” Ugarte said.
But, he said today’s astrotechnology has its own kind of magic. Not only can remote observing connect astronomers from thousands of miles away to a telescope in the Atacama, but modern telescopes can connect astronomers to worlds from farther away than ever before. Today, optical telescopes can capture images of stars that are tens of thousands of times fainter than those seen with the human eye.
In fact, these stars are so far away that it can take billions of years for their light to reach Earth. That means what an astronomer sees when looking at a faraway star is actually what the star looked like billions of years ago. The telescope basically serves as a rudimentary time machine.
“Everything you look at at night – those stars belong to our galaxy, and it’s part of our past,” Ugarte said. “When you look through the biggest telescope, you are getting one step closer to the beginning of the universe because you can look deeper into the sky.”
The farthest view into space, captured by the Hubble Space Telescope, reached 13.2 billion years into the past. Some scientists believe the universe itself has existed for 13.7 billion years.
A new space observatory, the James Webb Space Telescope, will be able to see even further into our past. The telescope is scheduled to launch in October 2018. Scientists expect it to see the very first galaxies, which formed just a couple hundred million years after the Big Bang. Whereas the Hubble showed astronomers the toddler stage of the universe’s life, Webb can reveal its infancy.
While the future of astronomy is both impressive and exciting, scientists are making new discoveries everyday with the technology we already have. Telescopes don’t need to be launched into space or able to see the beginnings of the universe to have an impact. Research astronomer Kathy Vivas has spent the past year observing at SOAR to investigate the formation of our own galaxy.
“Today, we believe that [large] galaxies form from the merger of many small galaxies,” she said. “That means small galaxies start merging together and, finally, they make a big galaxy like the Milky Way.”
To prove this theory, Vivas has been searching for the remains of small galaxies that were destroyed by the tidal forces of the Milky Way. If confirmed, the theory could also be used to explain the formations of other large galaxies like ours.
“For me, the most important reason why we are doing astronomy is because we can tell you where we are in the universe, what is our place in the universe,” Vivas said. “The fact that you can say, ‘Okay, we are here, this is the place we live, these are the surroundings we have, these are the dangers we may have in the future.’”
North of the equator, at UNC-Chapel Hill, graduate students and post-doctoral researchers are using SOAR to study distant, extinct solar systems. Chris Clemens, astrophysicist and senior associate dean for Natural Sciences at UNC-Chapel Hill, built SOAR’s Goodman Spectrograph. One of the telescope’s most crucial instruments, the Goodman Spectrograph is utilized during nearly 80 percent of SOAR research.
Clemens leads a UNC-Chapel Hill project on exoplanetary rubble. “When the sun is done being a regular star it will become a white dwarf, which is a very small, dense object about the size of the Earth,” he said. “Some of the leftover debris in the solar system will get crushed if it gets close enough, and then it’ll fall down onto the white dwarf.”
Clemens’ team examines the debris to determine which materials, such as iron or calcium, made up the planets that once orbited stars like our sun. Like Vivas, Clemens compares astronomical systems separated by space and time in order to help us better understand our surroundings in the past, present and future, and to discover more about our place in the universe.
It’s 7:15 a.m. on Thursday, the two students in Chapel Hill emerge from Chapman Hall. The sun is shining and the campus is coming alive with students headed for class. Tonight, another astronomer in another part of the world will sit down in a small room and stare at a series of graphs, diagrams and data, all accompanying an impressive image of a large, white star surrounded by hundreds more. In the corner, a screen will show a mustached man wearing glasses and headphones, whistling to himself as he aims the telescope toward the stars.
DeLaney McGuire is a student in the Media Hub program of UNC School of Media and Journalism.