Space Telescope Outer Galaxy Survey Helps Iowa State Astronomers

The two Iowa State University astronomers are using data from the Spitzer Space Telescope, that is now observing the outer reaches of the Milky Way, to progress in their star studies.

One of the two lucky scientists is Massimo Marengo, an assistant professor of physics and astronomy, that uses the information from Spitzer's infrared telescope to study big, colder stars and the dusty disks that form around them, as well as other stars in evolving planetary systems.

The second one, Charles Kerton, as associate professor of physics and astronomy, is studying star-forming regions within the Milky Way, thanks to data provided by Spitzer.

The two astronomers say that the space telescope is a vital part of their work, and without it they would have enormous difficulties or it would even be impossible for them to carry out their research.

“It lets me see objects that are obscured,” and where old surveys showed a single blob, the Spitzer images show a cluster of stars, says Kerton.

“It allows me to detect young, newly formed stars that wouldn't be seen any other way, and it shows them at a resolution that helps us understand what we're seeing.”

Marengo started working with the Spitzer experiment before it was launched, when he was on the staff of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts and he was part of the instrument group that built and calibrated the telescope's hardware.

“Spitzer is really, really sensitive,” he said, and “the first time it was turned on – before it was even calibrated – a 10-second exposure provided the equivalent depth of an exposure that used to take 10 hours with the 10-meter Keck telescope, the largest on Earth.”

For the astronomers that need to study very cool, faint stars, working with data from the Spitzer is crucial, Marengo said, and for his work, there is no other telescope on Earth that can match Spitzer's performances.

The Spitzer was launched August 25, 2003, into an orbit of the sun, equipped with 33.5 inch diameter telescope and three scientific instruments that detect infrared or heat radiation.

The telescope was cooled to -459 degrees Fahrenheit in order to reach the needed performances and even if last summer it ran out of liquid helium coolant, it still can provide data through its two shortest-wavelength detectors.

Massimo Marengo is a co-author of a new paper, published in the August 19 issue of The Astrophysical Journal Letters, that says that tight double-star systems are dangerous and could be “destroyers of worlds” as within their system, planet collisions would be frequent.

Charles Kerton has co-written a paper, published in the August issue of The Astronomical Journal, in which he identifies regions of the inner Milky Way that are forming intermediate-mass stars, thanks to Spitzer images.