SAN MARCOS - Vincent van Gogh once said that when he needed religion, he went out at night and painted the stars.
When Texas astronomer Don Olson and his fellow cosmic detectives need answers, they go out and look at them too.
Olson, his wife, literature professor Marilynn Olson, and physics professor Russell Doescher at Texas State University have turned a hobby into a life's work: looking to the stars, clouds and history books to unravel mysteries in great artworks, literary classics and defining moments in time.
The skies told them that a cataclysmic volcano eruption in 1883 inspired Norwegian artist Edvard Munch to color the sunset blood-red in one of the iconic paintings of our time. They revealed the exact minutes that the Dutch artist van Gogh painted his most famous starry nights.
They told why the Marines were slaughtered when they landed at Tarawa in the Pacific during World War II, what may have inspired descriptions of high tides in Geoffrey Chaucer's Canterbury Tales and how Ansel Adams captured his greatest photograph.
In August, as the 2004 Summer Olympics begin in Athens, Greece, Olson and his colleagues plan to release their theory of the time and date of legend's first marathon run -- calculated through stargazing and research about the end of the Battle of Marathon in 490 B.C. in Greece.
"We have a result that may be of some interest," said Olson, an astronomy and physics professor.
They're also working on theories surrounding James Joyce's Ulysses, expected to be published in the July issue of Sky & Telescope magazine, and at least one more Munch painting, Olson said.
The team has become internationally known as "astro-sleuths," and the members' theories that question the findings of art critics and guidebooks the world over are creating a buzz in artistic and scientific circles.
The professors start with what they can glean from history books, old letters, documents and newspapers, which may reveal dates, time frames or in some cases just a description of rain or a full moon. A computer program written by Olson helps calculate the position of the stars on any date in the past. They look at old weather records, tide gauges and photographs. They visitsites to dig through vintage road maps and watch sunsets, identifying vantage points and places the painter or writer may have been standing when inspiration struck.
They've created a class at Texas State designed to study astronomy in art, literature and history. And while they've earned accolades for their projects, it is their starry-eyed take on art masterpieces that gains them the widest recognition.
Their work, which spans nearly 20 years, highlights the symbiosis between art and science, experts say.
"A large portion of science is art, in that you're using your imagination to make up schemes about nature and your place in it," said Charles Whitney, a Harvard astronomy professor whom Olson considers a pioneer in using astronomy to study van Gogh. "Art is not science, and science is not art. But there's a tremendous overlap, and it's kind of fun to play around with that curiosity and see where that takes you."
To borrow another phrase from van Gogh, Olson and the others believe throwing back the curtain on a good picture is equivalent to doing a good deed.
"There are people who think we might be ruining art, picking it apart," Olson said. "We think it is enriched by, for example, this strange connection we can make between a brilliant work of art and a volcanic eruption half a world away."
In their most defining discovery, the team came up with what some call the most plausible theory yet -- published in February's Sky & Telescope -- about why Munch painted the sky red in his ghoulish 1893 painting The Scream.
Some say that it was Munch's own brilliance; others believe it was the brilliance of a typical Oslo, Norway, sunset that Munch captured.
Olson argues it was the 1883 eruption of Mount Krakatoa, one of history's most horrific disasters, which killed about 36,000 people.
The eruption of the volcano in Indonesia threw fine ash into the atmosphere. Startling red, blue, green and white sunsets swept the Earth for months. Reporters from New York to Oslo said they looked like wildfires on the horizon.