Above: : Ata Sarajedini stands in front of an image of a star forming
region in the Large Magellanic
Cloud (LMC), a satellite Galaxy of the Milky Way Galaxy. The new LSST
telescope could use observations of stars in the LMC to illuminate the
origins of the Milky Way itself.
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TWITTERShedding Light on the Origins of the Milky Way
High in the foothills of the Chilean Andes, a revolutionary new telescope promises to exponentially grow our understanding of the universe, both in the far reaches of space and in our own backyard. And UF is in on the ground floor.
Astronomy professor Ata Sarajedini and graduate student Conor Mancone have been accepted as members of the Stellar Populations Science Collaboration of the Large Synoptic Survey Telescope, or LSST. LSST is supported by the National Science Foundation, gifts from private foundations, grants to universities and in-kind support from Department of Energy laboratories and other LSST Member Institutions including Google, Inc.
The LSST is unlike any other telescope in the world. With an 8.4 meter primary mirror, the LSST’s light-gathering power, coupled with an extremely large imaging field of view will allow the telescope to take more than 800 panoramic images per night. In a week, it will be able to take two complete digital records of the entire sky visible from the southern hemisphere.
A powerful back-end data system, processing over 30 terabytes of data per day, will piece these images into a movie of how the sky changes over time. This unique ability to record the movement of objects and changes in brightness will allow the LSST to perform numerous experiments, including mapping near–earth objects – asteroids that are capable of someday impacting the earth – to locating dark matter and dark energy.
Sarajedini plans to use it to search for the origins of the Milky Way.
Using the LSST, Sarajedini and Mancone will look for RR Lyrae variable stars, whose apparent brightness changes over time. Observing these changes in brightness allows astronomers to determine the distances of these variable stars, which in turn provides a means by which to establish their three-dimensional distribution in space. The LSST will be capable of finding RR Lyrae stars previously unobserved in the diffuse outer halo of stars that surrounds the Milky Way galaxy.
Sarajedini believes these variable stars will reveal unseen structures within the halo.
“We can look out beyond the disc of the Milky Way and see if we can find structures, basically streams and filaments of stars, that are the leftovers of the formation of the Milky Way halo” he said.
These structures could prove the theory that the Milky Way formed from the disruption and accretion of many smaller satellite galaxies. These satellite galaxies are thought to be similar to the Large and Small Magellanic Clouds, irregularly shaped dwarf galaxies that are extremely close to the Milky Way.. Streams of RR Lyrae variables could be the vestigial tidal tails of these former satellite galaxies. Similar structures have been observed between the Magellanic Clouds.
LSST research of RR Lyrae variables could also shed new light on why these stars pulsate and yield insights into other specific properties of these variable stars.
Part of the University of Florida proposal involves following-up some of the LSST observations using the Gran Telescopio Canarias (GTC) on which UF has guaranteed time. The two telescopes would work in conjunction with each other – the LSST would identify targets of specific interest based on photometric research, and the GTC could follow up with a more detailed spectroscopic study of the same object.
The LSST primary mirror was cast in March 2008 at the Steward Observatory Mirror Lab in Tucson, AZ, and has begun the multi-year process of grinding and polishing. The mirror is scheduled to be completed in January 2012, and will be the largest two-surface optical mirror ever made from a single substrate. The LSST is scheduled to see first light in 2014, to begin doing science in 2015 and be in full survey operations by 2016.
Contact
Writer
Jeff Stevens, jstevens@clas.ufl.edu
Source
Ata Sarajedini, ata@astro.ufl.edu
Photo
Hubble Telescope, NASA
