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The bulk of an optical telescope is made of steel and glass. It is usually built to last a few decades, after which larger telescopes will take over.

During its lifetime, the utility of a telescope is often substantially increased every few years by upgrading the instruments that analyze the light collected by the telescope. This allows scientists to peer into new discovery space that was not previously accessible.

In fact, progress in observational astronomy is often closely linked with the advent of new instrumentation.

In this video, Dunlap Fellow Suresh Sivanandam explains instrument design and testing. He has been heavily involved in the design, integration, and commissioning of infrared instrumentation on ground-based telescopes.

Besides this instrumentation work, his scientific work involves the study of galaxy transformation in galaxy clusters through the use of space telescopes such as the XMM-Newton X-ray observatory and the Spitzer infrared telescope.

We don’t know much about the planetary populations around the coolest, smallest and most common type of star in our galaxy — the M-dwarfs. One approach to search for them is to watch a sample of those stars and wait to see if a planet passes in front.

This may be a long wait, depending on how many such planets there are and what their orbits are like. In addition, you have to be lucky for the planet to accidentally cross Earth’s line of sight to the host star.

To increase their chances, Dunlap Fellow Nick Law and his collaborators use a 1m-diameter robotic telescope that automatically checks on about 10,000 M-dwarfs many times each night. They then confirm their discoveries using the largest optical telescopes in the world.

Most of the mass in the Universe does not come from the atoms or even the nucleons and electrons that make up stars and planets.

Instead, most of the mass in a galaxy comes from something that cannot be seen through any telescope, whether optical, infrared or radio: for this reason, the invisible mass is called dark matter.

We don’t know what this dark matter is made of. What we do know is that it obeys the law of gravity: its mass influences the motion of stars in a galaxy. Thanks to this, Dunlap Fellow Anne-Marie Weijmans and her collaborators hope to come up with a map for the galaxies they’re studying.

They follow the unusual motion of stars within elliptical galaxies — which behave differently from our own spiral Milky Way — and try to work back from this map of velocities to a map of dark matter density.