Australasian Science: Australia's authority on science since 1938

The Amateur Astronomer

By Stephen Luntz

Trevor Barry has demonstrated that dedicated amateurs can still make important contributions to science, at least in astronomy.

Few scientists came to their field later in life than Trevor Barry, but he’s more than making up for the delay with enthusiasm – some might say obsession. Barry is an amateur astronomer, but the work he is doing with his personal telescope has had a major impact on our understanding of the planets and certain stars.

Barry had no interest in astronomy for much of his life, despite living under the dark skies of Broken Hill. “I spent my time walking around looking at the ground like everyone else,” he says. Then an apprentice with an enthusiasm for building his own telescopes passed through Barry’s department at Broken Hill’s zinc mine and persuaded him to come over and have a look.

“It got dark early, and I dropped my wife off at her mother’s place across town, promising to pick her up in half an hour,” Barry says. He then took a look through the 20 cm reflector with a home-ground mirror his colleague was using. “From working in the mines I was impressed with the mount he was using. Then he showed me Saturn. I could see the rings, Cassini’s division, five moons.”

Barry was dumbfounded. “I thought he was having a lend of me, I went around the front to see if he had a slide up there.”

Over the course of the night Barry was shown spiral galaxies, elliptical galaxies, star clusters, emission nebulae and planetary nebulae. “I finally picked up my wife at 2am,” he says.

Barry put his engineering skills to use, building his own telescope, then an observatory to protect himself and his machine from central Australia’s bitter winter nights. Infected by the bug that catches so many astronomers, he wanted ever-bigger telescopes, and now possesses one with a 40 cm diameter mirror. He has also designed his own flotation cell for his primary mirror and spider for his secondary mirror. He also runs a cooling system to ensure that the mirror is within 0.5°C of the air above it to avoid temperature distortions.

“I’m fastidious about collimation,” Barry says, referring to the process of arranging the telescope’s mirrors so that internal light rays are nearly parallel. “I use a double-pass laser and collimate for the altitude of the object I will be observing. If I move to a new object across the sky I recollimate.” The result is photographs of astonishing quality.

All this work paid off in 2007 when Barry took an image of his old favourite, Saturn and noticed a storm on the planet’s surface. The discovery was of great interest to NASA.

Although NASA has the Cassini Spacecraft (named after the discoverer of the largest division within the rings) in orbit around Saturn, the mission parameters are set months in advance. It cannot simply turn to follow a particularly interesting storm. “During the 5 months I tracked the storm, Cassini was only able to image it three times,” Barry says. “I did it 169 times.”

Saturn’s atmosphere bends radio waves, so the Radio and Plasma Wave Science team working on Cassini knew that a storm was occurring, but needed optical back-up to tell them where it was and what was driving it. For most of the storm’s life Barry was crucial to that support, along with three other amateur astronomers around the world.

Barry says the Saturn storms are formed from ammonia clouds, ammonia hydrosulfide crystals and water-ice crystals. “A poorly understood heat source drives ice up, causing lightning as it punches through the upper cloud layer,” he explains. On Earth this looks like a white spot, although Barry says at times it became very extended. The scale of the storm is enormous, with the lightning bolts 10,000 times as powerful as those on Earth.

The infrared spectroscope on Cassini has been used to analyse the chemical signatures of the storm, “for the first time seeing material dredged up from within the planet”. The combination of spacecraft and Earth-based observations is considered one of the highlights of Cassini’s mission, and Barry says NASA has given him considerable credit.

Saturn went quiet in mid-2008, but in February 2010 Barry was contacted by NASA’s Jet Propulsion Laboratory to alert him that a new storm had been spotted, and he was back on duty detecting its size and location.

Impressive as Barry’s telescope is, it’s far less powerful than any professional ‘scope. However, Barry says “the professionals don’t have time” to regularly note the location of storms on Saturn. “Hundreds apply for time on the telescope and only a few get chosen.”

The Hubble Telescope could afford to look at Saturn’s most recent storm just once. Consequently amateur contributions remain invaluable, although the level of equipment required continues to rise.

Sometimes what the amateurs do affects the professionals. When he and his friend, Anthony Wesley, were photographing Jupiter on 3 June this year Barry heard Wesley shout out. “I thought he had been bitten by a redback," Barry says. Instead he had witnessed the explosion when an asteroid or comet hit Jupiter. "It was a first in history, like Galileo seeing Jupiter's moons.” The Hubble and Keck telescopes were diverted from their planned agenda to witness the glowing aftermath.

Barry retired from his work 15 years after first sighting Saturn, giving him more time to devote to astronomy, and he enrolled in a correspondence course at Swinburne University. “I wondered why the Orion Nebula looked like it did; likewise planetary nebulae. I wanted to find out.” Barry had left school at fourth form (Year 10), and found going straight into a postgraduate degree intimidating. “I felt out of my depth,” he says. Nevertheless he graduated with straight high distinctions, his lowest mark being 91.

One of Barry’s units was on the history of astronomy, and he was one of two students taken to visit the Keck Telescope in Hawaii. “Standing in front of the Keck thinking of the work of the Herschels and Messier, I had tears running down my cheeks,” he says.

The course has opened up new avenues of interest for Barry. “I always thought variable star astronomers must be really bored people,” he says. However, once he learnt about the processes that cause stars to vary in brightness he became fascinated. “I’ve made thousands of observations,” he says, all of which help astronomers to gain a better understanding of the changes that occur within fluctuating stars.

Barry has become an evangelist for astronomy, although he says his mates “can’t believe it”. He adds: “There’s not a service club in Broken Hill that hasn’t had me”. Year 9 students from Sydney’s Methodist Ladies College make an excursion to the desert near Broken Hill, and have incorporated one of Barry’s sky shows into the schedule. Barry regrets that local schools have not shown the same interest. “I wish someone had lit this fire under me when I was a kid,” Barry says. “I doubt I would have worked in the mines.”