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)

March 1: Martian Summer

We hosted author, Andrew Kessler, and approximately 80 members of the general public on Friday, March 1st to hear all about the people and the science behind NASA's Phoenix Mars mission. Kessler spent a year with the engineers and scientists who worked on Phoenix to learn what it takes to launch a spacecraft from Earth and safely place it on the surface of another planet. Phoenix landed near the north pole on Mars, the first craft to ever land in the polar regions of the red planet. It's mission was to study the history of water in the ice-rich boundary of the Martian arctic. To do this, the Phoenix lander was equipped with a robot arm that could scoop up soil samples for analysis by an array of instruments including a mass spectrometer, a wet chemistry lab, and a high resolution imager. Not only did Phoenix discover subsurface water ice, but it also found that Martian soil contained high concentrations of chloride which converts to perchlorate in the presence of sunlight. You can read all about the Phoenix mission and Kessler's experience in mission control in his book, "Martian Summer: Robot Arms, Cowboy Spacemen, and My 90 Days with the Phoenix Mars Mission" and you can follow him on Twitter here.

After the talk, audience members toured our rooftop observatory (with the help of graduate students Jennifer Weston and Yong Zheng and undergraduate Jose Montelongo), viewed 3D movies (with undergraduate Bryan Terrazas), and listened to graduate student Steph Douglas explain the myriad of motions experienced by the Earth from our rotation around the Sun all the way out to the expansion of the Universe.

Join us for our next event on Friday, March 15th when post-doc Ashely Pagnotta explains how supernovae are used to understand the mysterious force known as dark energy.

--Summer Ash (Director of Outreach)

February 1: Saving Hubble

On Friday, February 1st, we kicked off our spring Public Lecture & Stargazing series with not a lecture, but a film. Saving Hubble is a documentary that chronicles NASA's decision to cancel the Hubble Space Telescope in 2004 and the subsequent public outcry. Filmmaker David Gaynes interviewed people far and wide on their thoughts about the pioneering space telescope that became a household name, from scientists and engineers who worked on Hubble to amateur astronomers, cabdrivers, and kids who are self-proclaimed "Hubble Huggers." After the screening, Summer Ash led Q&A with David and Ph.D. candidate, Christine Simpson.

If you missed the film, you can see a clip of it here and find out about upcoming screenings here.

The event attracted a sizable audiences of over 200 people who got to see some great sights from the rooftop telescopes after the film, thanks to the clouds that decided to clear out. Graduate students Jeff Andrews, Lauren Corlies, Ximena Fernandez, and David Hendel had telescopes trained on Jupiter and the Orion Nebula, both wonderful offerings of the winter sky. We also had the 3D wall up and running.

Join us on Feb. 15th for our next event: My Life as a Higgs Boson.

 --Summer Ash (Director of Outreach)

October 19: The Universe is My Lab

On October 19th, graduate student, Or Graur from the American Museum of Natural History, addressed a question always asked of astronomers - "What exactly do you do?"  Or walked an audience of 70 people through the process taken to publish his most recent work on supernovae - from forming the hypothesis to testing it with telescopes and equipment to finally creating the scientific plot of merit.  It was a great inside look at how we practice astronomy today.

Unfortunately, the weather was less than stellar and roof observing was not possible.  However, our 3D movie wall provided entertainment after the talk.

--Lauren

September 14: The Moon in 3D

On Friday, we kicked off a new season of lectures and stargazing with a talk by cartographer Jeffrey Ambroziak. He spoke about a unique map projection technique he helped develop, called the "Ambroziak Infinite Perspective Projection." This technique allows image data and topographical data to be combined into a single 3D map which appears undistorted regardless of viewing angle. During the talk, Ambroziak shared his beautiful and unique three-dimensional map of the Moon. He also shared a series of anecdotes, including the story of how he befriended the famous science fiction writer Ray Bradbury, who wrote the forward to his book "Infinite Perspectives: Two Thousand Years of Three-dimensional Map Making." Generously, Ambroziak provided every audience member with a full sized poster of his impressive 3D map of the Moon and red/blue glasses with which to view it. You can find more information about his projection at http://www.popviewmaps.com.

Unfortunately due to weather we were unable to observe, but audience members had the option to tour the rooftop observatory, view a 3D wall presentation by Bryan Terrazas, or listen to a slideshow on the moons of our Solar System presented by Rohan Sawhney. Thanks to our outreach director Summer Ash and all the volunteers that helped make the night a success.

Join us for our next Lecture & Stargazing event on September 28th at 8pm, where we will host a talk and book signing about black holes entitled "Gravity's Engines," by Caleb Scharf.

--Jana

December 16: How I Discovered A Supernova

We had a wonderful turnout for Caroline Moore's talk "How I Discovered a Supernova." Caroline gave an enthusiastic and informative talk that covered all aspects of her amazing discovery of SN2008ha. Caroline primed her audience with the background on stellar evolution needed to understand why supernova form and emphasized what types of stars ultimately end as supernova (not all do!). She mentioned some debate that has surrounded the classification of the SN2008ha -- indeed, SN2008ha has a very low luminosity and determining its class has required followup work using a wide range of telescopes to understand its nature. Caroline described the process of "blinking" frames that she used to find SN2008ha. There were many children present in the audience, and in the end she let them try to find SN2008ha by blinking the frames and letting them find the supernova. Indeed, this proved more difficult than expected but also got the point across that this kind of work requires extreme meticulousness. After the talk, Caroline answered a range of questions and this is when we learned that she also discovered another supernova recently: SN2009he!

Unfortunately, the sky was cloudy but around 40 people still went up to the rooftop observatory for a tour, led by grad student Josh Schroeder and assisted by Jeff Andrews, Curtis Cooper, Ian Allen, and Miao Li. Grad student Jana Grcevich led 3D visual simulations up on the 13th floor of Pupin Hall. In the lecture hall after the talk, undergrad Emir Karamehmetoglu and I showed the video "Cosmic Collisions" and this led to an open discussion on a variety of astronomy topics. Thanks to all the volunteers and the 170 people who came out for the night!

--Allyson