Graduate Students: Dan Li

“Six years ago, I wouldn’t have thought I was going to become an astronomer, but sometimes things change.” That’s what Dan Li says.

Dan Li is from China. He graduated from Tsinghua University in 2003 with a major on precision instrumentation. After spending three years at the Academy of Science and National Astronomical Observatories of China, working on astronomical infrared instrumentation, he developed a taste for astronomy and its tools.

“I found that astronomical telescopes are probably the best thing that combines mechanics and optics. I loved both, so I decided to pursue a career in Astronomy in order to keep improving my instrument-building skills.” Dan recalls.

But according to Dan, Chinese astronomy is more focused into theoretical research. “If you want to do cutting edge observational work, there are more opportunities in the U.S. to access the high end facilities around the world.” he explains.

For this reason, Dan applied to several U.S. schools and got accepted in many of them. He was seduced by UF Astronomy Department’s instrumentation program and now he is on his fifth year here.

Talking to him, it seems like he is happy with his choice “I think this is a very good department. It has they right size and people are very friendly, so you know every student and every professor. It also has a very strong background in instrumentation building and that allows students to use a lot of facilities around the world.” he says “Also, Gainesville has a very good climate and a clean environment. It is not a big city, not too noisy and a very interesting spot. In Florida you can visit many nice places both in the Gulf and in the Atlantic. I have two main hobbies, travelling and railroads. Here I can enjoy both.”

Dan Li works on his thesis under the advice of Professor Charlie Telesco. He studies protoplanetary discs (discs of dust floating around young stars) around certain type of stars called “Herbig Ae/Be” stars. On this kind of star, the disc is very suitable for mid infra-red observation, allowing scientists to learn more about the planet formation processes that happen on them. Prof. Telesco is the lead investigator of some of the most important mid IR instruments around the world, and that gives Dan access to that instrumentation. “This is a very interesting topic, as exoplanetary systems are very popular in nowadays astronomy.” Dan says.

Dan also works on the commissioning of CanariCam, a high tech, heat sensitive camera, built by Prof. Telesco. This is instrument was created to work on the world’s greatest optical telescope, the Gran Telescopio Canarias (GTC), located in La Palma, Spain. This instrument will allow peering through obscuring interstellar dust with unprecedented accuracy.

Due to his work Dan was invited to attend to the GTC meeting just held in the island of La Palma. “It was very interesting for me, as my work is tightly related to the GTC and CanariCam. Many instrumentation groups gave talks about their plans for this very special telescope. There are a lot of great ideas and projects going on. From the information I got and from my own personal opinion, I think that the GTC will do very well soon.”

Dan Li is currently focused on getting his PhD degree, which will happen in one or two years. Eventually, he wishes to become a professor and do research. In the long term he would like to do something for his home country, China, and contribute to reduce the gap between Chinese and Western astronomy.

“Being an astronomer is not a job one does just for survival. I love the starry nights and the feeling you get when you are up in the mountain, under the shining stars and the Milky Way. Then I realize that I really enjoy my job and this is something that not everyone can have in their lives.”

Graduate Students: Jesus Martinez

Jesus Martinez says his life is marked by places where he has lived. “When you are a child you want to be part of a place. Have some stability.” he says.

After he was born, his family lived in Madrid for five years, then Germany for three years and after those, four years in Mexico. Then he went to Seville for College, expending his last year in Germany, and now he is 26 and is in Gainesville for his PhD.

The reason, at least in the early years, was his father. He is a physicist, so his life and his family’s, was conditioned by the requirements of an early scientific career. “My father was anomalous in the scientific world, because I was born when he was only 20 years old, so I had to follow him: first his doctorate in Madrid and then several post-doctoral contracts.” Jesus explains.

With this background, is natural that young Jesus didn’t want to be a scientist. But, when he was seventeen and had to decide what to study in College, he chose physics. “I realized that I really liked it. I guess I knew what it was and had lived with it all my life to have it very clear. Also, as an adult, I started to value the great experience that has been to grow up in different cultures.” he admits.

His main motivation was, and still is, to understand how the universe works. “To answer the great questions: where does the universe come from and how does it work. On graduate school I decided to focus on the biggest scale of all that, which is astrophysics or cosmology.”

Jesus’ PhD is funded by a grant that UF gives each year to a Spanish student, as part of its participation on the Gran Telescopio Canarias telescope, the world largest optical telescope, built in the Canary Islands (Spain).

He had another offers in Germany but he decided to come here for many reasons. First he had more freedom to choose for his research. “Here is like having a menu to choose from. In Spain and in Europe, grants are subject to a specific project, so you cannot choose. I also wanted to go to a new place.” Jesus says. “A thing I do really like here is that everybody encourages you to go on with your research. People are very supportive.”

This year, Jesus has published his first paper, based on data from the GTC. “My advisor, Rafael Guzman, and I sent a proposal and it got accepted. Then I had to analyse all the data and we had very good results. This was a very long process, especially until it got published.”

Jesus feels that the moment when he was told his paper was accepted for being published was the best of his recently started scientific career: “The reason to be of a scientist is to publish papers. You can do a lot of work, but if nothing gets published, is like you haven’t done anything. It doesn’t count. One doesn’t get to publish very often, so it’s always great news.”

Jesus says he's happy to be an UF astronomy graduate student. “There are many good astronomy departments in the US. Here we are among the top ones and we have access to the GTC. I am one of the fortunate ones that have had access to the data and could use them for my thesis. This is something that in another institution I probably couldn’t have done.” As a final conclusion, he says “If you like science and know what to expect from a scientific career, go for it.”

Graduate Students: Deno Stelter

Deno Stelter defines himself as a Colorado boy from the Western Slope. He doesn’t remember when he started to like astronomy, probably because he liked it even before he could remember. According to his parents his first word was “light” and as a child he used to read sci-fi books and later every general-level astronomy book he could get his hands on.

Astrophysics seemed a natural choice for him so he went to University of Colorado at Boulder, for college. He spent one year abroad, in Germany. He picked Germany because his dad has German ancestry. “I went to Bavaria, in southern Germany, which is the fun part of the country. I speak some German, but with southern accent, so other Germans make fun of me.”

At the beginning of his last college year, he told his professors that he wanted to go to grad school. One of them looked at him and answered: “Ok, but let me tell you, every year we graduate ten people in astrophysics, of those half apply to grad school and of those half get in. From those who get in and finish their programs half will get a job in the industry and the other half won’t find any jobs, and from those who get the jobs, only half of them will become professors.” It’s a pessimistic point of view but somewhat right, says Deno, but he decided to pursue it anyway.

While facing the regular trials and tribulations, like taking the GRE and figuring out which schools to apply to, Deno talked to his undergrad advisor who told him to check the UF instrumentation program. “I did, and I found that there were a lot of cool things going on. I also applied to University of Arizona, California Santa Cruz and Hawaii. UF was the first school I heard back from so it made the choice very easy.”

Deno, working along with Prof Stephen Eikenberry, has inherited a project previously developed by former graduate student, Mark Keremedjiev. The second-generation of an instrument called SPIFS which stands for SPeckle stabilized Integral Field Spectrometer. Its successor has been named Speckle Stabilized Science Demonstrator, “that’s S^3D, or Scubed D, which sounds like Scooby Doo. I’m so proud of that name” Deno says.

The purpose of the instrument is to nullify the effects of the atmosphere in ground based telescopes and to do it cheaply. “If we get the funding, we are planning some major changes. The heart of the system is a fast steering mirror, which basically moves following the movement of atmosphere, so the light from the object we are observing always hit the same point of the detector or CCD. We are getting a faster one and also, buying a better guiding camera and a new science camera. I’ll also be doing lab experiments redefining the algorithm that moves the mirror. I’ve been talking to a Russian professor in physics; he worked on mis misssile guidance systems back in the Soviet Union. He explained how, when guiding a rocket, they compensate the time it took for the computer to calculate the orders by considering where the rocket will be instead of where it was and meanwhile everything else was moving and getting ready. As a result the system worked much faster. I thought this could be useful to speed things up with our instrument. So let’s see how things work out. I have to play around with that.”

This is only part of the work for a 2^nd year student. Deno has also to attend his classes and he teaches two groups of students as a teaching assistant. “I don’t have much time to enjoy all the other things in Gainesville. Luckily my fiancé is here which keeps me sane. There is much to do here. Specially there is a great German bar called ‘Stubbies & Steins’ which makes me feel like I’m back in Germany.” 

But Deno and his officemates have other hobbies well known by the entire department. An arsenal of NERF weaponry fills the shelves of their office, number 401. If you enter there you might step into an open war at any time. Any provocation might pull the trigger to a nasty battle where foamy darts fly in every possible direction. According to Deno, it all started when graduate student Connor Mancone, brought “a simple 6 barrel NERF gun” and shot Robert (Morehead) with it. Robert said that wont do and got himself another gun, and that prompted Amanda (Townsend) to get one. That’s how the arms race begun. “When office 401 was cleared out to grad students it just accelerated. For his birthday Robert got a much bigger gun and things snowballed. ..  vdgdvIt got really big, and now we have almost enough to supply every member of the department with at least one weapon and ammo to spare. It’s disturbing, but also a great release of tension. Maybe at some point we will organize a major battle”

Graduate Students: Daniel Capellupo

Dan Capellupo is a native from New Jersey.

In junior high he felt inclined to be an astronaut and go to space. He was good with maths and science looked like a logical option for his future. His father used to have astronomy magazines at home and looking at the cool pictures on them, he figured out that he could stay in the ground and study those things from here.

After going to the University of Rochester in New York for undergraduate, he had no idea of what area of astronomy he was going to dive in. So, he applied to schools all over the country. He recalls “I mostly wanted to get out of the North East. I got accepted to several schools, but I found out that UF offered a lot of options, so I could decide what I wanted to study after I got there.”

After five years and about to finish his PhD he says: “It seems like I made a good choice, things have worked out here so far. The department is continually growing and improving and there is a lot of interesting research going on.”

Dan works with Prof Fred Hamann on a project studying quasars. Quasars are very bright objects in the center of some galaxies, mostly pretty far away. “The ones I study are around 10 billion light years away.” He explains.

In the early life of some galaxies there is a quasar phase that probably lasts up to 50 million years. The quasar has a super massive black hole in the center surrounded by a disk of accreting material. Studying the gas clouds that surround the Quasar it’s possible know more about its evolution and how it affects to the rest of the galaxy.

For his observation, Dan used two telescopes, the MDM 2.4 meters and the 2.1 Kitt Peak telescope, both at Kitt Peak observatory in Arizona. These are relatively small telescopes and don’t have an operator, like the bigger telescopes which have their own crews of technicians. “I had to operate the telescopes myself. A couple of times I've been alone there. It is a great experience, but kind of scary if something goes wrong. Even being small telescopes they may cost a couple of million dollars and if you break it people will be upset with you.”

 

After doing the research comes the time of publishing the results. “It’s a long process. You have to write the paper, summit it, and it can go back and forth with the referee until it’s finally accepted. When my first paper was accepted for publication I felt like I was officially a scientist.” Dan says.

Besides doing his classes and research, Dan was on the board of the grad student association for 4 years. “The first year I was treasurer and then the next two years I was a student-faculty liaison. I had to meet with our graduate coordinator and with the chair of the department to explain any problems that the graduate students were having or to find out things that we, the graduate students, should be aware of. So we tried to keep the communication open between faculty and students.” He remembers. “The past year he was president which means he was in charge of the organization, making sure that meetings where held every month to discuss issues and things to be taken to the faculty. “In one hand you have to deal with problems and issues, but it also is a social position. It’s a big department with many students.”

Finally, he says “If you consider coming here, I would say that there are a lot of good things in the department. There are a lot of research opportunities and in almost all the fields of astronomy. Also, the people here form a nice, friendly community and if you seek help for something they are going to be there.”

Graduate Students: Knicole Colon

If you ask Knicole Colon she will say she is from New Jersey. Originally born in California, her dad was in the Air Force, so they had to travel a little bit when she was young. Her family background is from Puerto Rico and, although she is third generation born in US, she still can speak some Spanish.

Knicole is passionate about astronomy but admits that the way she got into it is pure cliché. When she was 8, her dad used to take her to see meteor showers, which she found to be magical and exciting. When the movie “Contact” came out some years later her fate was sealed: “That and my meteor shower experience was enough to make me see astronomy as something cool and exciting; so I decided to go and look for aliens!” She jokes.

While working on her undergraduate in physics at The College of New Jersey, she joined a summer research program on star formation at Arecibo itself. Already feeling like Jodie Foster she came to UF with the intention of working on star formation, “but it happens that the UF Astronomy department has great faculty working on a wide range of research, and I got to meet Prof. Eric Ford. After talking to him I found that he had some interesting projects going on, so I started to work in exoplanets” Knicole says.

Prof Ford was selected to join the Kepler Mission Science team, being the greatest NASA research project on exoplanets so far (Kepler mission). Working with him, Knicole started doing simulations of Kepler data, even before the mission was launched. “This work was great and I used it for my masters project, but I was working on simulations. I wanted to get my hands on some real data” She remembers.

Fulfilling her desires, the GTC, the world’s largest telescope, started operating. The University of Florida was a partner into the GTC’s construction, so it has guaranteed observing time on it. Knicole was involved with a new project at the very beginning of its operation, trying to see planet transits. “I evolved from simulating light curves to acquiring them from a really big telescope” she says chuckling. “I remember when I finally got my first light curve from the GTC, how nice it was. That was probably my best moment as an astronomer so far. Our technique worked and I wanted to use it for most of my thesis work; it’s a very unique tool to use.”

In between the masters and the GTC, she also helped with operating the Rosemary Hill Observatory, which belongs to UF. Prof Ford set it up to participate in a project observing a transiting planet with a very long transit duration. Twelve hours of observations were needed to see a full transit, so several telescopes had to be used because typically nowhere on Earth is dark for twelve hours at a time. “Prof Francisco Reyes helped us a lot, and there we were; the three of us at the telescope in the summer of 2009. We actually got some data and observed part of the transit. It was awesome.”

Learning with this basic telescope helped Knicole to get ready for her observations at the GTC. “They are totally different telescopes and systems, but you have to learn somewhere.” She explains. “Since then, people have continued to use the Rosemary Hill telescope and it’s available for all students to practice.”

Knicole continues to use the GTC to get data for her thesis and has travelled twice this year to its location in La Palma for observing runs. She aims to graduate in 2012. “It’s hard to keep up with research and apply for jobs at the same time, but I think I can do it. It is not in my nature to quit.” She says happily.

Graduate Students: Izaskun San Roman

Izaskun always had it very clear: she was going to be either a musician or an astrophysicist.

She liked astronomy, but wasn’t your typical amateur astronomer, who knows all the names of stars and constellations. What lured her in was the search for answers, to try to unveil the knowledge behind all those names. “And while you can always have a harp in your living room, a 10.4 meter telescope like the GTC is a bit harder to fit,” she explains.

Following this reasoning, she moved to the Canary Islands, home to one of the best Spanish schools for astrophysics; La Laguna University, a long way from her hometown in northern Spain.

After college, she got married and spent two years working as a high school teacher, while her husband finished his own studies. Then she resumed her studies and started to look for schools to get her PhD, and applied for a Spanish government grant to support science done with the new GTC, by forming new astronomers at the UF. She got accepted and both of them came to Florida.

During her first year here, she took a class with Professor Ata Sarajedini about stellar populations. “I loved this class. Also, an important thing about doing a PhD is getting along with your thesis director, and I found that Prof. Sarajedini had a very organized way to work and a lot of experience. I take my work very seriously, I almost get obsessed with it, it goes home with me and I never truly disconnect. So far, I think I made the right choice.” Izaskun recalls.

But what does it mean to study stellar populations? “What I do is try to understand how galaxies form. Galaxies usually have different morphologies; they may be elliptic, disc-shaped, spiral galaxies... We want to understand how the universe is capable of creating such different kinds of galaxies. This can be done from different angles, for example, studying the gas in the galaxy, or the stars in different parts of the galaxies, or some other factor in different parts of the galaxy. What I do is study stellar populations; that is, groups of stars. To study a single star is difficult, but when there is a group you find that they have some special characteristics, because they were born at the same time in similar conditions. For my thesis I use this kind of stellar populations, called “clusters,” in a nearby galaxy called M33. By studying these clusters, we can understand how the galaxy was formed. It is funny, because at the end of the day I can’t say that I am an expert in this galaxy; only in its clusters.” Izaskun explains.

Besides her thesis, she has also joined a group that works with the Hubble telescope. “It's paying work, but that also means working double.” According to Izaskun, there is a difference between how people get their PhD’s here and in her home country “I have the feeling that here the work done by students is considered more valuable. Being a student doesn’t mean that your work is worthless, just that you are learning.”

But hard work is not the only thing she does “I like the life in Gainesville. It’s a nice small city, with a good quality of life and a great University vibe. I do enjoy having a big American style house, pretty close to campus and downtown. If you want some more action, Orlando and Jacksonville are very close. The only thing I miss is walking everywhere, like in European cities.”

Now she is very close to graduation and can look at things in perspective. “My time here has been great. You might have some low times, but it will pay off, as it’s a very comforting and satisfactory work. Also, every day the department is getting more prestigious. We aspire to get into the top ten and a lot of effort is being made toward that goal, not only to give everyone an outstanding education, but also to make being an UF doctorate a guarantee of the high quality of your work.”

Graduate Students: Mark Keremedjiev

Like most children his age, when he was eight, Mark Keremedjiev (Born in Pennsylvania, 1984; moved to Montana 1988) wanted to be an astronaut. For him this dream evolved into a true goal so when he was in high school he had the space program in his mind. “It was either being a scientist or going to the navy and becoming a pilot. I liked astrophysics and finally got in astronomy following this path,” Mark says.

Mark graduated cum laude in astrophysics at Cornell University in 2006. He was interested in instrumentation building so his advisor told him about the work of Stephen Eikenberry, a former Cornell professor at that time already in UF.

“I remember when I first met Steve,” Mark recalls, “He was really excited because he just got an NSF grant he was competing for with Caltech. He was very happy, pounding the table in excitement. At that moment I thought that I would really like to work with him.”

Once here, he got involved in a project to build a new type of instrument aimed to reduce the negative effect that the atmospheric turbulence has in ground based telescopes.
As Mark explains, telescopes work like a photo lens: the bigger they are, the more magnification you get. But this is only true until you reach about 15 centimetre diameter telescopes. Further on, the constant movement of the atmosphere degrades the images.

The instrument he worked on takes hundreds of pictures every second to compensate for these effects in real-time. This technique is called Speckle Stabilization. “I hope it can be used on 10 meter class telescopes. I’ve built a version that actually works and tested it in the 4.2 meter William Hershel telescope in the Canary Islands. I was able to conclude that when the instrument was on we got higher resolution that when it was off. That was the whole point of my thesis, to show that this is possible.”

Mark remembers the moment he realized that the instrument actually worked: “My best moment as a scientist so far: a very happy eureka moment. I started to dance and run around the control room in excitement. Was really neat, to see working something that just three years before was only a sketch in a piece of paper!”

Mark is also a musician, an athlete and likes to get involved in campus life. He was president of the Graduate Astronomy Organization and student representative in the Graduate Curriculum Committee.

He also joined astronomy department’s outreach efforts. “Our department does great work in outreach. I’ve been giving talks in schools to about five hundred students a year. It’s a great thing for us to do because people have such a fascination with astronomy that whatever you tell them, they become transfixed. When I was a child, I enjoyed similar talks too; in fourth grade we had an astronaut come to talk to my class. This was one of the most memorable events in my young life.”

Mark now has his PhD in Astronomy, and keeps the honest goal of becoming an astronaut. He even trained for and ran an Ironman race, with the objective of getting the necessary physical strength. Unfortunately, recent changes in the US space policy altered his plans. He is moving to Washington D.C. to pick up a government research position for twelve months with a prize fellowship from the Oak Ridge Institute for Science and Education. When it finishes he has been awarded an NSF international research fellowship to go work at the University of Cambridge on lucky imaging.

“For those thinking about graduate school, I’d say that now is a great time to come to Florida. There is an excellent faculty that covers a lot of research areas. Some of the graduate students starting right now will be using the 10 meter GTC telescope for their data and that is a very appealing thing. I’m really glad I came here. I had the opportunity to work with a great instrumentation person like Steve Eikenberry on a project in which I wasn’t just a cog in a wheel. If you go to other schools sometimes you’ll just be working on a subsystem of a piece of a part of a big instrument. Here, I did the simulations, the design work, the integration, the testing, the data analysis… I really got to do the whole thing and that is an experience you don’t get in many places.” says Dr. Keremedjiev.

Mark Keremedjiev graduated in May 2011.