Archives

All posts for the month October, 2013

“Focusing the Hard X-ray Universe” — Dr. Daniel Wik

Posted by admin on October 4, 2013
Posted in: DTM Astronomy Seminar.
NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, has captured these first, focused views of the supermassive black hole at the heart of our galaxy in high-energy X-ray light. Taken from wikipedia.

NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR, has captured these first, focused views of the supermassive black hole at the heart of our galaxy in high-energy X-ray light. Taken from wikipedia.

Dr. Daniel Wik visited DTM this morning to give a talk about NASA’s NuSTAR mission, an X-ray telescope in low-Earth orbit designed to study some of the most exotic and energetic phenomena in the universe.

For example, the image at left shows observations taken by NuSTAR of the center of our galaxy. In recent years, astronomers have learned that a supermassive blackhole looms at the center of our galaxy, gobbling up gas.

The images at left show a flare bursting from the galactic center, made of gas heated to 180 million degrees Fahrenheit (100 million degrees Celsius) as the black hole sucked material down into its deep, dark center.

“Recent Results on Exoplanets and Brown Dwarfs” — Prof. Chris Tinney

Posted by admin on October 3, 2013
Posted in: DTM Seminar.
This image of the brown dwarf binary CFBDSIR 1458+10 was obtained using the Laser Guide Star (LGS) Adaptive Optics system on the Keck II Telescope in Hawaii.

This image of the brown dwarf binary CFBDSIR 1458+10 was obtained using the Laser Guide Star (LGS) Adaptive Optics system on the Keck II Telescope in Hawaii. Taken from wikipedia.org.

Good DTM seminar today by Prof. Chris Tinney, presenting a long and fascinating list of results from exoplanetary astronomy.

Among many projects his group is working on at the University of New South Wales, they are observing potential planet-hosting stars for the radial velocity signals of gas giant planets in orbits with long periods, comparable to Jupiter’s period of 12 years. Such planets require long observational baselines to find because you must observe the planet-hosting star for at least one orbital period, 12 years, to conclusively say that you’ve found such a planet. As a result, there aren’t too many long-period exoplanets known.

His group is also looking for brown dwarfs, exotic objects that aren’t quite stars but aren’t quite planets either. Brown dwarfs have masses large enough (probably greater than 13 times Jupiter’s mass) that they can fuse deuterium in their interiors — unlike planets — but small enough that they don’t fuse the lighter isotope, hydrogen — unlike stars.