Friday, May 31, 2013

UIS professor to study the massive star Eta Carinae using the Hubble Space Telescope

University of Illinois Springfield Associate Professor of Astronomy-Physics John Martin is part of a group of scientists that will be studying the massive star Eta Carinae using the Hubble Space Telescope.

Martin will utilize a specialized technique he developed to measure the changing brightness of the star. The collaboration, headed by Dr. Andrea Mehner of the European Southern Observatory also includes astronomers in Japan and Minnesota. The researchers plan to study ongoing changes in the brightness and spectrum of Eta Carinae using ultraviolet wavelengths of light that cannot penetrate the Earth’s atmosphere.

“We can only do this type of research by utilizing the Hubble Space Telescope,” said Martin. “This is a rare opportunity to observe a star on the verge of going supernova before it explodes.”

Eta Carinae is one of the most massive stars in our galaxy with a mass more than 100 times the Sun. Its history of violent outbursts and eruptions includes one in the mid-nineteenth century when Eta Carinae briefly became the second brightest star visible in the night sky. During that Great Eruption it ejected an expanding shell of material that is visible today through a small telescope. Astronomers think that these outburst (called “supernova impostors”) are part of the life-cycle of the most massive stars before they explode as supernova.

“The atoms of iron in your blood and the calcium in your bones were made inside the core of massive stars like Eta Carinae,” said Martin. “Astronomers want to understand how supernova impostor activity helps disperse the atoms manufactured deep inside these stars.”

Eta Carinae, at a distance of about 7,000 light years from Earth, is too far south to be seen in the night sky in Illinois, but in the last ten years it has brightened enough to become visible to the naked eye in parts of the Southern Hemisphere.

“We have theorized that Eta Carinae is at a critical stage and may undergo dramatic changes over the next few decades,” said Martin.

Time on the Hubble Space Telescope is allocated through a competitive peer-review process with only about 20% of proposals successfully earning time. Martin and his colleagues were awarded eleven “orbits” (roughly the equivalent of 8 hours) over the next two years.

“It might not seem like much but it’s a great affirmation of your work to be chosen by your peers,” said Martin. “We expect to get a lot of productive science out of the time we have been awarded.”

For more information, contact Martin at 217/206-8342 or

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