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)

December 6: Comet of the Century?

In the year after Comet ISON's detection in September 2012, many predicted that its close encounter with the Sun would produce a show worthy of the title "comet of the century".  However, as graduate student Erika Hamden showed, Comet ISON's passage was less spectacular than predicted, though no less interesting.  The comet's orbit showed that it came from the Oort cloud, a sphere of small icy bodies surrounding the Solar System.  Objects in the Oort cloud probably spend most of their time around 0.75 lightyears from the Sun, but occasionally a nearby star can perturb the cloud and send comets into the inner solar system.  Since Comet ISON came from the Oort cloud, it hadn't interacted with the Sun before and so it could provide information about the composition of Oort cloud bodies.

Erika played movies like the one above from several space-based solar observatories (i.e., NASA's Solar Dynamics Observatory, NASA's Solar and Heliospheric Observatory, and NASA's Solar Terrestrial Relations Observatory) showing Comet ISON as it approached the Sun and after its closest encounter. Astronomers had predicted that, after it passed by the Sun, Comet ISON would be very bright and spectacular to see. However, the comet broke up when it got close to the Sun.  The movies showed that some bright debris reappeared after Comet ISON passed the Sun, but it faded rapidly, indicating that the comet had fallen apart. Comet ISON was probably a loose ball of ice that was destroyed by the Sun's heat, like a poorly-made snowball that falls apart before reaching its target.  Although it was not the "comet of the century", Comet ISON provided astronomers with plenty of information about Oort Cloud comets and provided everyone with a great show.

Clouds and rain prevented any roof activities, but undergraduate Claire Ding showed 3D movies on the 13th floor, and graduate student Andrew Weis gave a slideshow of highlights of the winter sky in the lecture hall.

--Steph Douglas (graduate student)

November 8: Astronomer vs Astronomer

Scientists do not always agree with each other, and many times, scientific progress is made through debates. On Friday, November 8th, graduated student Jennifer Weston gave a public lecture about a few of the greatest arguments in astronomy in the past 150 years, and how they were resolved. One of the biggest debates in the history of astronomy and astrophysics, the 'Great Debate', was about whether the Milky Way, our own galaxy, was the entire universe, or there were other galaxies out there, seen as the "spiral nebulae". The debate was eventually resolved by the work of Edwin Hubble, which shows that the spiral nebulae are not only galaxies outside of our own, but they are also moving away from us at high speeds. 

After the lecture, many people went to the roof where graduate student Adrian Price-Whelan showed off the Moon and Albiero along with Andrew Emerick, Susan Clark, Aleksey Generozov, and David Jaimes. On the 13th floor, visitors enjoyed 3D astronomy movies with Barnard student Gladys Velez-Caicedo. In the lecture hall, graduate student Yuan Li presented a slide show on planets outside the solar system found by NASA's Kepler telescope. 

Join us on November 22 for a lecture by Jeremiah Murphy on supernova explosions.

-- Yuan Li (graduate student)

March 2: Grumpy Bert

On Saturday night, graduate student Munier Salem and Director of Outreach Summer Ash helped kick off the opening of a spectacular photography exhibit at Grumpy Bert in Brooklyn. The exhibition entitled "The Universe in Color" runs through the end of the month and features 22 large format images of the Universe taken by astrophotographer (and physician) Robert Gendler.

Munier opened the evening with an informal talk on light and how astronomers make use of the entire electromagnetic spectrum in order to learn as much as possible about the Universe. Then the 40+ audience members asked some very astute questions ranging from the expansion of the Universe to extraterrestrial life. The event culminated in a lively reception which allowed everyone to examine Gendler's amazing works up close and personal.

Additional photos from the event can be found here.

August 5: Practical Astronomy

While we're sad that summer is ending, this happily means the return of our lecture series! We started off on an unique and interesting note with Dr. M. Ryan Joung giving a talk on how astronomy can have practical uses or in his own words, "on the usefulness of 'useless' knowledge." Ryan used many examples to highlight the advances astronomy have spurred in other fields. Did you know that your GPS system uses quasars to calibrate the positions of its satellites in the sky? Or that they rely on Einstein's theories of special and general relativity for accuracy? Ryan also pointed out that taking and processing images have been the forte of astronomers for decades. Their work with CCDs have helped make modern cameras possible. Also, image processing techniques that astronomers use to study structures in galaxies are now successfully being used to identify cancer cells. While focusing on the practical aspect of astronomy, Ryan concluded by reminding us that astronomy is beautiful and we truly do it to understand our place in the universe.

After the lecture, we were lucky enough for the clouds to stay at bay and had our first public observing session of the new semester on the roof. Munier Salem, Josh Schroeder and Christine Simpson showed people the Moon, Saturn and Albireo. Meanwhile, Jana Grcevich led people on a "Tour of the Cosmos" using the 3D wall. Finally, some remained in the lecture hall to listen to presentations about JWST and Kepler from Lauren Corlies and Yuan Li. Overall, it was a great start to the semester.

July 22: Gattaca

A couple of weeks ago we wrapped our summer science film series with the movie "Gattaca." Once again we had another good turn out for some sci-fi movie fun! Plus, we all had a chance to take a break from the oppressive heat of that week!

The movie centered on two main themes, genetic engineering and space travel, which mirrored both the debate in the late 90's on cloning and genetic engineering of humans and the launch of the Cassini-Huygens mission in October of 1997 (which was the release date of the movie!). After the movie, we talked about the scientific background behind genetic engineering and about the fact and fiction behind traveling to Saturn's moon Titan. Highlights of the talk included acknowledging the groundbreaking work done at Columbia, in the Fly Room, where fruit flies were used to understand genetic heredity. We also talked about the genetic engineering used today in making human insulin in bacteria. In regards to space travel, we dispelled the notion of going to Titan and back in one year and had a good discussion about future prospects in space propulsion - pointing to solar sails, ion rockets, and rail guns - a fitting discussion in light of the canceled shuttle program. I also pointed out that this movie is full of science which also includes nods to electric cars, solar energy, and genetic identification.

Two of our graduate students, Jana Grcevic and Christine Simpson, led the telescope viewing from the Low library plaza and Brandon Horn, also a grad student, helped out with movie setup. Thanks to everyone who came to watch, stayed to talk science, and gazed upon the heaven afterwards.

Summer Astronomy Events

Two events happened over the last two weeks involving Columbia Astronomy's Outreach Program.

First, on Friday May 27 at 7 pm, about 30 people came to this year's inaugural Science Fiction Movie Night. Due to the success of last year's program, this year, we're screening science fiction films in Pupin Hall that have astronomical themes. Our calendar for the summer can be seen here, and there will be four additional ones before August.

May 27's movie was Red Planet starring Val Kilmer. Graduate student Lia Corrales led the discussion after the film about the various aspects of science fiction and science fact found in the movie. The people in attendance generally gave her rave reviews, if not the film. After the film, a few astronomers set up a six-inch Dobsonian telescope on College Walk and gave out free views of Saturn.

Then, last Friday, June 3, a number of Columbia Astronomers took telescopes over to Brooklyn for a star party associated with the World Science Festival. Many members of the general public came out and looked through the telescope at various astronomical targets. Hundreds of people got a chance to see Saturn, so it certainly was a success. See pictures of it here.

Don't forget: this Friday, June 10, another blockbuster movie, "The Fifth Element" will be shown with astronomy graduate student Jeff Andrews leading a discussion on the science truth and falsehoods present in the film.

March 11, 2011: IceCube Astronomy

On March 11, one of our senior undergraduates majoring in astrophysics, David Fierroz, gave a talk about a neutrino telescope that he worked on last summer, IceCube. David talked about how IceCube was built at the South Pole and he described the long trip to get there. About 150 visitors came by to hear how the telescope is opening up a new branch of astronomy, discovering objects in a completely new way. As arguably the largest telescope in the world, IceCube will be able to observe some of the most extreme phenomena in the universe including supernova, and supermassive black holes at the centers of galaxies.


Afterwards, one of our incoming graduate students, Jia Liu, gave a talk about a standard day and night at Kitt Peak National Observatory. Also, one of our graduating students explained how Stellarium works and showed the conjunction of planets over the year. While the weather was not great enough to look at stars through the telescope, we were able to give tours of the telescope roof and dome, and even look at the moon.

February 11, 2010: Galactic Sleuthing Lecture and Public Observing

This past Friday, Dr. Allyson Sheffield, a current post-doc of the Columbia Astronomy department, gave a talk entitled, ''Galactic Sleuthing: Unraveling the Milky Way’s Past.'' In her talk, Allyson described two prevailing models for galactic formation. First, 'monolithic collapse' posits that a galactic-sized gas reservoir (of Hydrogen and Helium) collapses all at once, creating an old population halo of stars first and then flattens out into a disk composed of younger stars. Second, she presented the theory of 'hierarchical merging' that posits that galaxies are built up from the accretion of smaller galaxies and the merging of bigger ones.

Allyson then talked about how we can determine which scenario better describes the evolutionary path of our own galaxy by looking at both the group motions of stars and their shared chemical abundances. By showing us data and simulations by Rodrigo Ibata and his collaborators and by our very own Prof. Kathryn Johnston, respectively, she showed us how the merging Sagittarius dwarf galaxy was discovered by surveying stellar velocities in the galaxy along with models that describe how the dwarf galaxy would currently look which were later confirmed by additional chemical abundance observations.

Finally, she showed us how one can merge the two indicators of common ancestry to look at moving groups closer to us and determine if evidence for other accreted dwarf galaxy remnants remain in the galaxy by looking at the spectra of stars with similar peculiar velocities. She found that she could likely link certain groups to larger ones seen in the galactic halo stellar streams by models that would predict the location of these peculiar stars. Given her research and the other research she presented, we learned that merging plays a significant role in galaxy evolution and that one can recount this evolution based on remnants of past accretion events.

We had a great turn out and our attendees made full use of our facilities by watching astronomy visualizations on our 3-D wall, ran by graduate student Jana Grcevich, and by going to the roof to stargaze. It's cool to think that many of the stars we observed, including our own, exhibit group origins or movements that were probably even more defined in the past.

Thanks to the 8 volunteers and the 130 people who attended our lecture and observing night!

October 29 Outreach Report

Postdoc Josh Peek gave an excellent lecture on Friday, October 29,
titled "Outer Space" to about 250 visitors. We took a tour of space
near to us and far away as Josh proved outer space isn't just "space"
but rather that most of the atoms in the universe are in the form of
soot and gas hiding in between planets, stars, and galaxies. The
audience was treated to pictures and explanations of the many forms
this matter can take. These include cold clumps of gas and dust which
block out the light coming from behind them and can sometimes form new
stars, as well as hot gas in clusters which can rip a galaxy's gas
right out of it. After the lecture many people were able to observe
Alberio, the double cluster, and Jupiter and four of it's moons. In
addition to observing, guests were also able to watch a 3D wall
presentation on Mars by Cameron Hummels, or to watch the film Cosmic
Collisions. Thanks to all our visitors and to all the volunteers for a
great night!

Yeshiva University Outreach

On October 7 at 7:30 pm, about 30 students from the Chemistry Clubs at Yeshiva University visited the Astronomy Department to get a tour of the heavens. Graduate student, Jana Grcevic gave a presentation on color and chemistry of the heavens as well as a view of our 3D movie theater. Then, we proceeded up to the roof to get views of Jupiter, Alberio, and the Ring Nebula.

Sept. 3: Frits Paerels Talk and Remote Observing

On Friday, Sept. 3 some 140 people attended a lecture by Dr. Frits Paerels about missing matter in the universe. Dr. Paerels described how astronomers came to understand that most of the matter in the universe was unaccounted for. Showing beautiful images of clusters of galaxies and simulations of the large-scale structure of the universe, Dr. Paerels described how only 4% of the universe was made out of normal matter and how fully 50% of it hasn't yet been detected.

After this great talk, we were treated to a remote observation by graduate students Neil Zimmerman and Andrew Brown who imaged Stephan's Quintet using the website slooh.com. These observations were a big hit with our regular visitors. Other newcomers were treated to a tour of the observatory on the roof with an exhortation to return soon!