Richard McDermid from Gemini Observatory will describe how astronomers measure the properties of black holes in “Lighting the Dark: Weighing Super-Massive Black Holes with Lasers on Mauna Kea” at ‘Imiloa Astronomy Center’s next Mauna Kea Skies program at 7 p.m. on March 15.
“A black hole is a concentration of matter so dense and massive that even light cannot travel fast enough to escape its gravitational pull,” McDermid said. “At the heart of our galaxy lies a black hole of truly monstrous proportions, weighing more than 4 million times heavier than the sun.
“But this is a small-fry by cosmic standards. In galaxies more massive than our own Milky Way, black holes can reach masses of more than 10 billion solar masses. Even though these black holes are enormously massive, how can we measure their properties if they emit no light?”
McDermid will describe how astronomers use the world’s biggest telescopes to observe the universe’s biggest black holes, using lasers to correct for the effects of Earth’s atmosphere and complex instruments to measure the orbits of stars passing close to these gargantuan black holes.
He will describe how astronomers are using these techniques to find black holes that even appear “too big” for their host galaxy. The audience will look at the most distant reaches of the observable universe, to when the universe was in its infancy. Using telescopes on Mauna Kea, astronomers made the surprising discovery that super-massive black holes managed to form just 800 million years after the big bang, posing new questions to theories of how such massive black holes form.
‘Imiloa is at 600 ‘Imiloa Place in Hilo, off Komohana and Nowelo streets at the University of Hawaii at Hilo Science and Technology Park. Cost is $10. Purchase tickets at the ‘Imiloa front desk or by phone at 969-9703. For more information, visit www.imiloahawaii.org.
McDermid, a native of Scotland, obtained his Ph.D. in astronomy from the University of Durham. He spent five years at the University of Leiden in the Netherlands before coming to Gemini Observatory in 2007.
His research is focused on how galaxies form and evolve in the universe, using detailed observations of nearby galaxies. He leads an international team of researchers using many of the world’s most powerful telescopes to study the chemistry and motions of stars in these galaxies, as well as their gas and dark matter content, and is a recipient of this year’s Royal Astronomical Society Group Achievement Award for this work.
Mauna Kea Skies program will be hosted by Peter Michaud, also of Gemini. He will provide observational highlights of the current night sky over Hawaii, pointing out prominent constellations and stars one can see during this time of year.
The monthly planetarium presentations are held on the third Friday of each month.