June 14: Cowboys & Aliens

Last Friday, June 14, we screened the joint Western+SciFi action film "Cowboys & Aliens" for an audience of enthusiastic movie-goers. We started the night with a short film, "The Shot", a 5-minute piece about a magical camera lens that works as a teleportation device. The short portrays a man who finds and then uses the lens to travel the world, but trouble arises when he accidentally takes a photo that has him travel out of this world!

The feature, "Cowboys & Aliens", is a genre-mashup that asks "how would a pre-1900, small western town handle an alien invasion?" The answer is: Daniel Craig, the film's leading actor. The film combines references to classic western films like "A Fistful of Dollars" alongside clear homage to sci-fi movies such as "Alien" and "Close Encounters of the Third Kind" (up next in our summer film series). Though there is not much science to discuss in the movie, we did estimate that the height of the alien rocket is about ~3 times the size of a Saturn V at about ~10 times the width. One wonders how the aliens use gold as a power source for such a large vessel...

Join us next time on July 12th for our next Summer Film & Stargazing Event!

--Adrian Price-Whelen (graduate student)

May 3: Why Dark Matter Matters

On Friday night, Kerstin Perez, a post-doc here at Columbia, told us that we can only see about 20% of the mass in the universe. The matter in the universe is mostly stuff that we can't see. The way that stars move in galaxies tells us that there's a lot more mass in those structures than we thought. But this extra mass doesn't emit light or interact with magnetic fields - we only see its gravitational effect. Because the matter doesn't emit or absorb light, astronomers have named it 'dark matter'. The current theory posits that dark matter is a fundamental particle that rarely interacts with normal matter, and then only via the weak nuclear force.

Kerstin also told us about the different ways scientists are looking for dark matter particles, including her own research. She built an instrument that flew on a balloon over Antarctica and attempted to detect the particles that form when two dark matter particles run into each other and annihilate. Other astrophysicists at Columbia are involved in a part of the ATLAS project at CERN that could detect dark matter particles from high energy collisions that simulate the early universe. Still others work at big underground detectors where they try to detect dark matter particles passing through Earth.

After Kerstin's talk, most of our audience members headed up to the roof of Pupin where Saturn and Arcturus were on display through our telescopes. The sky was clear and people were especially excited to check out Saturn's rings. A few folks chose to delay their observing to listen to a short presentation on the Herschel Space Observatory, the European Space Agency's infrared telescope which ran out of coolant last week and is no longer in operation. Others watched films about the universe on our 3D wall. 

--Steph Douglas (graduate student)

http://www.esa.int/Our_Activities/Space_Science/Herschel

April 19: Extragalactic FM

On Friday, April 19th, Ph.D. candidate Destry Saul shared with us the wonders of the Universe as seen  in the radio portion of the electromagnetic spectrum. He introduced the audience to some of his favorite radio images taken with his favorite radio telescopes. Radio telescopes can either be single dish (like Arecibo or Parkes) or arrays (like the VLA or the VLBA). Objects that emit in the radio include galaxies, supernova remnants, and pulsars. Destry's favorite objects include the closest and most powerful radio source, Cygnus A, and the brightest radio supernova remnant, Casseopeia A.

Unfortunately, the skies were quite cloudy, so observing was replaced by tours of our rooftop observatory given by graduate students Adrian Price-Whelan and Steph Douglas. Audience members were also treated to a guided viewing of our 3D Wall by undergraduate Gladys Velez-Caicedo, and a discussion of the other end of the electromagnetic spectrum, X-ray astronomy, by graduate student Yuan Li.

We hope to see you at our next event on May 3rd.

--Summer Ash (Director of Outreach)

April 5: Eyes in the Sky

On a beautifully clear (almost) spring night, PhD student Ximena Fernandez gave a talk entitled "Eyes in the Sky" to a packed room of over 200 people. Ximena's talk focused on how the combination of space telescopes that operate at a variety of wavelengths have been invaluable in revealing the secrets of our Universe. Starting with our galactic center, she showed how only through the use of infrared and X-ray data have we begun to understand the nature of our galaxy's supermassive black hole. Moving to nearby galaxies, GALEX images revealed the largest known spiral galaxy, which has extended spiral arms thanks to an ongoing interaction with another galaxy. At the end, Ximena presented the newly released Hubble Extreme Deep Field, the single longest exposure in all of astronomy. The image contains over 5 billion galaxies, including the oldest known galaxy to date. The talk ended with a video that zoomed through the image to show the distribution of the galaxies in the picture. You can watch the video here!

After seeing so many wonderful images, the good weather gave everyone the opportunity to see amazing objects with their own eyes.  Most popular were the Orion Nebula and Jupiter.  Some chose to remain in the lecture hall where there was a presentation on the Cosmic Microwave Background and the new results just released by the Planck Telescope.  Finally, there was also the possibility of experiencing our 3D wall. Everyone had a great time and we're looking forward to our next event.

--Lauren Corlies (graduate student)

March 21-23: Stargazing with BAM

In partnership with the Brooklyn Academy of Music (BAM), Columbia Astronomy Public Outreach put on a trio of stargazing sessions in Brooklyn over spring break. These "star parties" were a complement to another event at BAM on those same nights entitled Planetarium - a musical collaboration between Bryce Dessner, Nico Muhly, and Sufjan Stevens. The three musicians produced an collection of songs by the same name inspired by the Solar System. 

We transported four telescopes (three Dobsonians, and a Celestron) from the Upper West Side of Manhattan to the Boerum Hill neighborhood of Brooklyn and set them up on the roof of the new Fisher Building. Even though it was quite cold and windy, the skies were extremely cooperative, allowing for a full hour of observing on all three nights. Our celestial targets included the Moon, Jupiter, the Orion Nebula, and the Mizar-Alcor star system. 

Huge thanks to BAM for reaching out to us and to all who attended. Special thanks to all our volunteers - undergraduate: Doug Thornhill; graduate students: Lia Corrales, Ximena Fernandez, Erika Hamden, David Hendel, Duane Lee, Jenna Lemonais, Steven Mohammed, Dan D'Orazio, Adrian Price-Whelan, and Munier Salem; and post-docs: Josh Peek and Matt Turk. 

--Summer Ash (Director of Outreach)

(Photo credit: Ed Lefkowicz)

March 20: School Visit

Over spring break, Professor Kathryn Johnston hosted a group of 30 high-school students from the New York Harbor School. Prof. Johnston discussed her research on "galatic cannibalism" which focuses on how the Milky Way has evolved over time by gravitational interactions with other galaxies, i.e., capturing and accreting them. Prof. Johnston also spoke with the students about various career paths into science. Following the talk, the students toured the Rutherfurd Observatory with undergraduate Doug Thornhill.

March 15: Cosmic Candles

Last week, Ashley Pagnotta, a post-doc at the American Museum of Natural History, gave a talk entitled, "Supernovae: Cosmic Candles of the Universe." Ashely's research focuses on stellar explosions known as supernovae which occur toward the end of a star's life. Different phenomena give rise to different types of supernovae and by understanding the nature of these explosions, astronomers can better constrain the parameters that help us describe the behavior of our Universe. 

It was less than a hundred years ago that astronomers even discovered that the Universe wasn't static, i.e., "standing still". Using the doppler effect to measure the speed at which galaxies were moving away from Earth and cepheid variable stars to measure distance, Edwin Hubble made a plot of of these two variables and discovered that the farther a galaxy was from Earth, the faster it was moving a way from us. Today, we call this plot the Hubble Diagram in his honor and continue to update it as we make better and better measurements. You can make you own Hubble Diagram using data from the Sloan Digital Sky Survey here. 

While Hubble's work showed that Universe is expanding, it said nothing about the future of this expansion. To investigate this, two teams of astronomers proposed using Type 1a supernovae to probe the Universe out to greater distances, and therefore farther back in time. They used Type 1a supernovae instead of cepheid variables as these supernovae have a characteristic explosion that allows astronomers to use them as a standard candle of sorts; astronomers know how bright they are at a given distance so they can observe them at various distances and extrapolate their true distance based on their observed brightness. Both teams ended up discovering that the expansion of the Universe was *accelerating*, giving rise to the theory of dark energy, and as a result we awarded the Nobel Prize for Physics in 2011. 

Ashely went on to explain how studying how Type 1a supernovae form in more detail can help astronomers minimize errors associated with their distance measurements and thereby improve our understanding of dark energy. You can view the slides from Ashely's talk here. 

Unfortunately, the skies were cloudy again so after the lecture, the 120+ audience members toured the roof with the help of graduate student Adrian Price-Whelan, viewed 3D movies with undergraduate Jose Montelongo, and learned about Comet PANSTARRS with Director of Outreach, Summer Ash, and graduate student Yong Zheng. 

Please come see us on April 5th when graduate student, Ximena Fernandez, will present highlights from lesser known space telescopes that are providing astronomers with great glimpses of the Universe. 

--Summer Ash (Director of Outreach)