October 5th - Slooh your way to the stars

What's in an acronym? Paige Godfrey, Slooh's research director, gave us an overview of the services offered by this online observatory. As of today, Slooh provides access to six telescopes. The majority, 5, are located in the Canary Islands. These include their largest instrument with an aperture of 0.5 meters (20 inch). Another telescope in Chile gives access to the many interesting objects located in the southern sky, and a solar scope equipped with a narrow band H-alpha filter allows observations of the solar chromosphere. By locating their observatories under some of the darkest skies, they facilitate access to high quality observations to individuals who would live in areas that suffer from light pollution (all cities).

Individuals can access the data obtained by the cameras attached to Slooh's telescopes. Paige showed some examples of work done by members of their community, from processed images, mosaics and gifs, to discoveries of new comets. Since the processing of astronomical data can have a rather steep learning curve, they're developing materials to make it easy for anyone to get started.

Paige explained how these resources allow schools to incorporate observational astronomy into their curriculum, and they're launching a specific program, AstroLab, with the support of the National Science Foundation.

As an illustrative example of how Astronomy can help answer some of the most fundamental questions we've asked ourselves through history, Paige introduced the use of Drake's equation, a way to quantify the number of communicating civilizations in a given volume, and applied it to the set of stars visible in a typical image taken with one of Slooh's telescopes. Turns out vulcanians may be out there for real!

-- Jose Zorrilla (graduate student)

September 21 - Clocks of the Universe

Imagine that half of your wedding guests show up at the venue a month before the event because the government’s decision to add a month to this year’s calendar did not reach them. Turns out that such a scenario could not be completely ruled out in ancient Rome. Mihir Kulkarni, our speaker on Friday, opened our eyes to how the way we measure and keep track of time has evolved through history and how different cultures use different systems.

Until recently, no man-made device could match the regularity of celestial movements. As a result, we used the Earth’s spin, its rotation around the Sun and the Moon’s movements to measure time. These measurements became encoded in the calendars that helped regulate human activity, from seeding to religious festivities. Small differences between the actual movement of celestial bodies and that captured by calendars add to the point where they become noticeable and sometimes, disruptive. Such disagreements were often dealt with through ad-hoc adjustments, but ultimately they inspired calendar refinements based on more accurate astronomical models. This way, we learned about hard-to-measure phenomena such as the precession of the Earth’s rotation axis. As the axis wobbles not unlike that of a spinning top, the closest star to the north pole -called the North Star-, changes. This shift occurs on timescales of thousands of years, long compared with a person’s lifespan but measurable through history.

Finally, minute perturbations and secular changes to the Earth’s movement relative to the rest of the universe pose a fundamental limit to the precision with which we can measure time. To beat these limitations, our current time standards do not rely on astronomical calculations anymore, but that has not removed all implementation challenges, as the “Unix 2038 year” problem illustrates.

After the talk, Mihir answered many insightful questions from the audience. You can also find a detailed summary of the talk by Steven Fertig, of the Amateur Astronomers Association of New York, here.

Clouds prevented us from star gazing, but we had the opportunity of touring the Rutherfurd’s observatory facilities lead by Daniel and Matthew while Douglas discussed some counter-intuitive properties of black holes with the support of animations in our 3D wall.

-- Jose Zorrilla (graduate student)

Feb 19 - Ripples in Spacetime

A record crowd packed into the lecture hall tonight to hear Jillian Bellovary talk about gravitational waves and how to detect them. Jillian's research focuses on supercomputer simulations of supermassive black hole binaries, but her presentation focused on much less massive binaries like those whose merger was detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in September. Gravitational waves are very small distortions in spacetime caused when massive objects are accelerated to high speeds. The distortions measured by LIGO were smaller than the radius of a proton -- and those were caused by two ~30 solar mass black holes merging together. Jillian showed simulations of how these ripples in spacetime are created by the two merging black holes.

Jillian also described how LIGO was able to detect these tiny distortions. LIGO is an interferometer, meaning it measures how light waves interfere with each other (either adding together or canceling each other out) after they travel a very long distance in two perpendicular directions. How the interference pattern changes with time tells LIGO scientists how the distance is changing in each direction. If the "arms" of the interferometer lengthen and compress in a particular pattern, then they know they've detected a gravitational wave!

The sky was cloudy, but graduate students Adrian Price-Whelan and Lauren Corlies, along with undergraduates Amanda Quirk and Cierra Coughlin, showed off the Rutherfurd Observatory. Meanwhile, undergraduates Richard Nederlander and Tze Goh screened short films on the 3D Wall. In the lecture hall, volunteers Stephanie Douglas, Maria Charisi, and Danielle Rowland played videos from PhD comics and from members of the LIGO team at CalTech, and answered audience questions about gravitational waves.

--Stephanie Douglas (graduate student)

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)

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)

November 30: Galactic Neighborhoods

On November 30th, about 100 people joined us to hear Columbia Astronomy Professor Jacqueline van Gorkom talk about how galaxies are influenced by their surroundings. Professor van Gorkom is a radio astronomer and does extensive research on galaxies. She showed us how strikingly different galaxies look in dense clusters of galaxies compared with fields. She explained that when a galaxy enters a galaxy cluster filled with hot intra-cluster gas, the cold gas inside the galaxy gets stripped out of it and thus star formation is quenched, which changes the color of the galaxy from blue to red. The audience raised a lot of interesting questions about galaxies and gravity.

After the talk, some people went to see the 3D movies on the 13th floor shown by Columbia undergraduate student Gladys Velez-Caicedo. Unfortunately, the sky was not clear on Friday, but Columbia Astronomy graduate students Adrian Price-Whelan and Jenna Lemonias gave a telescope tour to a group of people on the roof of Pupin. In the lecture hall, graduate student Yuan Li presented a slide show on spiral galaxies and Dr. Jana Grcevich talked about the Big Bang and the expansion of the universe.

Join us on December 14th for the last event of this semester: a panel discussion on Life, the Universe, and Everything!

--Yuan

November 16: Living with the Stars

Dr. Helena Uthas's talk was of a different strain than most of our previous outreach events. She shared her experiences of the three years she spent as a support astronomer on the beautiful and isolated Spanish island of La Palma, off the coast of western Africa. It is one of the prime spots for astronomy in the world today, having the best “seeing” available on our little blue planet (seeing is how much the atmosphere perturbs the images of stars as seen through a telescope).

In this personal narrative, Dr. Uthas walked the audience of ~180 people through her time at the Swedish Solar Telescope (SST) and the Nordic Optical Telescope (NOT) and the life of an astronomer in such a remote location. We were shocked and impressed by the difficult loneliness that such a job requires, yet there also was a sense of lusting for the introspection afforded being in one of the most beautiful and untouched natural vistas in the world. After this captivating mix of science, nature, and self, the majority of the audience went up for observing. We had almost 200 people on the roof throughout the event, and our telescopes were pointed at the extremely bright Jupiter, along with the Pleiades star cluster and the Andromeda galaxy. Several people stayed in the lecture hall for a slideshow on galaxies. The evening wrapped up around 9 pm leaving attendees having played astronomer over the skyline of New York City and vicariously experiencing the life of an observational astronomer through Dr. Uthas.

 --Emir

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

October 5: X-ray Spectacular!

On October 5th, over 175 people came to Doug Thornhill's talk on the newly launched X-ray telescope NuSTAR. NuSTAR was assembled at the Nevis Laboratories of Columbia University and Doug worked with the NuSTAR team for almost four years as an undergraduate student at Columbia since the beginning of the project. He provided a clear and thorough explanation on how x-ray telescopes work, with a physical demonstration on how light is detected by the telescope. Doug then showed how NuSTAR was built and discussed the scientific goals of the telescope including the survey of super-massive black holes, supernovae remnants and compact objects, as well as the study of the energy transport of our sun.

After the talk, some people stayed in the lecture hall to enjoy the movie "High Energy Vision: The Chandra X-ray Observatory," which is another NASA X-ray telescope launched more than a decade ago. 

As it was a fairly clear night, many people headed up to the roof to view the night sky through the telescopes. Additionally, Columbia undergrad, Bryan Terrazas, showed 3D movies on the 13th floor. 

Join us for our next event on October 19th, when we will hear from Or Graur on how astronomers use the universe as their laboratory.

--Yuan

April 27: How is a Hubble Image Made?

The beautiful pictures of our universe provided by the Hubble Space Telescope are some of the most inspiring in Astronomy. This past Friday, PhD student Christine Simpson explained to attendees how these images are made. Explaining the basics of the telescope, CCDs and the color-assignment process, everyone could walk away with a deeper appreciation of these images.

In response to requests from several audience members, Christine has provided the following links related to her talk: Hubble’s Hidden Treasures contest and contest submissions to date; a nice explanation of the meaning of color in Hubble images; and an article from Sky & Telescope that describes Hubble image processing.

After the talk, some stayed to hear about Hubble's successor, the James Webb Space Telescope. The cold weather also provided clear skies for observations on our roof. Columbia students helped visitors observe Saturn, the Moon, and the Mizar-Alcor star system in the Big Dipper's handle. Visitors were also able to experience our 3D wall. Our next lecture of the semester is May 11th. We hope to see you there!

 --Lauren

April 13: History of Astronomy and Navigation

On April 13, 260 people crowded a lecture hall in Pupin Physics Laboratories to hear Brandon Horn, graduate student in the Department of Astronomy, gave a lecture on the history of astronomy, navigation, geodesy, and photometry. Wowing the crowd with a zooming presentation, Brandon gave us a tour of major astronomical discoveries starting with the size of the Earth and moving all the way up to the expanding universe. People stayed after the talk to ask questions and explore the universe of Astronomy Picture of the Day in the lecture hall while others headed up the roof for a beautiful, clear view of the heavens.

On the roof, five volunteers helped visitors look at Mars, the Moon, the globular cluster M3, and the Orion Nebula. We were very fortunate to have such a clear view of the night skies and the huge number of visitors seemed to attest to how exciting it was to be able to use the observatories to their fullest capacity. Additionally, visitors who wanted to avoid the crowds could catch a show in our 3D theater where graduate student Yuan Li showed some videos about black holes and pulsars that the audience enjoyed. In all, a fun time was had by all.

--Josh

March 30: Space Rocks in the Neighborhood

During our last public outreach night, Columbia Astronomy Professor, Greg Bryan, took a break from his normal schedule of simulating the processes of cosmic galactic evolution to inform us about objects a little closer to home. In his talk entitled, ''Space Rocks in the Neighborhood: The Dangers of Near Earth Objects,'' Prof. Bryan discusses the forces governing the orbits of near-earth objects (NEOs) and how many have impacted the Earth in the past. He explained that there are different types of NEOs depending on whether they cross the Earth's orbit or circle just inside or outside of it. What makes these objects dangerous is that for many asteroids and a few comets larger than a 1 kilometer (~.6 miles) across, real catastrophic damage can be done, with many global causalties.

Prof. Bryan also described the ranking system for potential threats by NEOs which is based on the size of the approaching object and the "projected" distance from impacting Earth. He pointed out that the key to adverting disaster by impact is to know the orbits of all concerning NEOs well in advance of a potential impact. If the orbits are known, then various efforts can be utilized to nudge the object out of an impacting trajectory towards Earth. While new telescopes and surveys have greatly expanded our knowledge of these potential "doomsday" rocks, only a complete survey of these objects, with multiple snapshots (to determine orbits), can help us prepare to deflect them out of harm's way.

Finally, Prof. Bryan pointed out different methods that can be used to deflect the objects in orbit ranging from painting the rock in a highly reflective coating such that photon pressure from solar rays can slowly push the rock away to detonating a nuclear warhead next to it to give it a more pronounced and immediate impulse away from a harmful trajectory towards Earth. You can read about NASA's Near Earth Object Program at their website and explore the near Earth environment for yourself, virtually of course, at the Minor Planet Center.

It seems that many people are concerned about our ability to track and advert a catastrophic impact, considering we had 260+ people in attendance. Even though the weather wasn't cooperating that evening, many people remained to enjoy our post lecture activities by either staying in the lecture hall and discussing the science in Astronomy Picture of the Day images, led by undergrad Jose Montelongo, or watching 3-D astronomy shows, run by graduating grad student, Jana Grcevich.

Our next public outreach lecture is on Friday, April 13th and is entitled "Where the Ocean Meets the Sky."

--Duane

March 16: Our Galactic Neighborhood

On March 16 at 8 pm, 190 visitors joined us in Pupin Hall to hear from Dr. Gurtina Besla, an expert in predicting the past and future trajectories of galaxies interacting with our own Milky Way galaxy with special emphasis on the Large and Small Magellanic Clouds. She showed us results from her research that have yet to be released indicating the exact manner in which the Andromeda Galaxy and the Triangulum Galaxy will interact and merge with our own galaxy eventually forming a new galaxy: "Milkomeda". Attendees were wowed by the ability for theoretical astrophysicists like Dr. Besla to predict the future of our galactic environment up to 8 billion years from now.

After the amazing lecture, visitors were treated to glimpses from our 3D Wall, a discussion of Astronomy Pictures of the Day, or a tour of our rooftop telescope facilities. Unfortunately, the clouds and haze prevented us from having a view of the heavens this week, but we cross our fingers for future Public Observing nights, the next one scheduled for March 30. Join us then!

--Josh

February 27: Harlem Sidewalk Astronomy

Five members of our department ventured out on a beautiful, clear evening into neighboring Harlem last night. We brought with us two small telescopes and loads of NASA bookmarks and posters to give out to interested participants. Setting up on the Federal Plaza at 125th street and Adam Clayton Powell (just down from the Apollo Theater), we pointed our telescopes towards some of the highlights of the sky this season: Jupiter, Mars, and the first-quarter Moon. Many curious passersby stopped to see what we were doing there and to take a glimpse of the heavens. Some individuals just wanted a chance to see the sky, while others wanted to discuss something astronomical they read in the news or heard from a friend.


In the end, the clouds came up to block our celestial viewing, and the wind shook our telescopes and made it unpleasant to stand around. We returned home, satisfied to have reached out to around 120 people over the course of the night. Great work, Bryan, Jennifer, Jose, and Marcus!

--Cameron

February 17: Life in the Universe

Last night, we had a very successful outreach event headlined by PhD student Maureen Teyssier discussing where to look for Life in the Universe. She outlined the various components we understand to be necessary for life to exist elsewhere in the Universe including appropriate elemental materials, liquids, energy and stability. Furthermore, she pointed out the various ways in which we humans are searching for life, both in and out of the Solar System. If you want to know more, Maureen's talk was inspired by "The Search for Life on Other Planets" by Bruce Jakosky.

There were excellent conditions for observing, so attendees who went to the roof got to catch a glimpse of Jupiter and its moons, the Double Cluster, and the Orion Nebula through our telescopes. We also the 3D Astrowall demonstrations of educational astronomy briefings. In the lecture hall, there was discussion of recent astronomical news of observations and modeling of galaxy collisions and a Q&A period with graduate students and postdocs from the department. In all, we had about 200 people come join us.

Our next event is Friday, March 2nd, hope to see you then.

--Cameron

February 3: Top 11 Astronomy Stories of 2011

Last night, graduating grad student, Jana Grcevich, kicked off our Spring lecture series by recapping the "Top 11 Astronomy Stories of 2011." Some of the highlights included: the most massive galaxy cluster found, a possible detection of the Higgs boson, a possible detection of a supermassive black hole devouring a star, the 2011 Nobel Prize in Physics going to three astronomers, and the discovery of over 3000 new exoplanets.

Jana ranked the new planet discoveries as number one on her list and many people would agree. Understanding and determining the available real estate for life to grab a foothold in our galaxy, let alone the rest of the Universe, ranks as one of the top 3 questions asked by humanity since humanity could ponder its own existence. Jana explained how the discoveries were made, by the Kepler space telescope, by stating that it measures the dimming of light from a star to determine the nature of the object causing the dimming due to occultation (the object passing in front of the star). She then focused on some of the gems from this exciting database of planets which included the discovery of a super earth-massed planet (roughly 2.5x) orbiting around its star in the habitable zone - an object known as Kepler 22b. Afterwards, she pointed out some planets orbit around binary stars, giving a shout out to the fans of Star Wars who recall Tatooine’s planetary system. Last, but not least, she displayed the best determination for many planetary systems’ orbits and configurations which showed us that planetary systems similar to our own are actually common place and not rare as previous thought based on the planetary systems discovered before the Kepler mission.

Many good questions were asked from the 140+ attendees last night, proving that a recap of the LAST year’s exciting discoveries was a great way to start off THIS year’s lecture series.

--Duane

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

November 18: The Truth About Black Holes

On Friday, November 18th, over 200 astro enthusiasts gathered in Pupin to hear "The Truth About Black Holes." Dan D'Orazio shed some light on these enigmatic photon traps, discussing gravity, the equivalence principal and time as a malleable entity. Dan cut past the hype and speculation surrounding these theoretical predictions, and instead focused attention on the astrophysical contexts in which black holes exist, and how we can spot them.

Afterwards folks ascended to the roof, where Hugh Crawl, Jeff Andrews, Lauren Corlies, Sam Gordon and Lia Corralles showed visitors Jupiter, the Pleiades and Andromeda. For those who stayed downstairs, Munier Salem and Jenna Lemonias led a short quiz on Planet Trivia, which was entirely too easy for the stalwart enthusiasts.

--Munier