Date: February 17, 2011

Title: Buckyballs in Space!


Podcaster: Rob Sparks

Organization: NOAO –

Description: Letezia Stanghellini received her undergraduate degree in Astronomy at the University of Bologna (Italy) in 1983, with a thesis on the evolution of central stars of planetary nebulae (PNe), and her Ph. D. in Astronomy at the University of Illinois at Urbana-Champaign in 1995, also on PNe, with the supervision of Dr. J. Kaler. From 1988 to 1998 she served as an assistant astronomer at the Bologna Observatory. In 1998 she became an ESA associate astronomer at the Space Telescope Science Institute in Baltimore, working in the science policies office. In 2004 Letezia came to NOAO as an associate astronomer working for the Telescope Allocation Committees group and supporting GMOS on the Gemini telescopes.

Bio: Rob Sparks is a science education specialist in the EPO group at NOAO and works on the Galileoscope project (, providing design, dissemination and professional development. He also blogsmmn at

Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by Robin West.


Rob: Hi, and welcome to the 365 Days of Astronomy podcast. This is Rob Sparks from the National Optical Astronomy Observatory in Tucson and I am here with Letezia Stanghellini is that correct?

Letezia: Yes, that is.

Rob: And we’re here to talk about some of the work she has been doing with extragalactic Buckyballs, right?

Letezia: Galactic and extragalactic.

Rob: Galactic and extragalactic, so first why don’t you tell me a little about your position here at the National Optical Astronomy Observatory.

Letezia: Yes, I am an astronomer here, an associate astronomer with NOAO and for my functional work I support the Gemini Observatory and for my research I work mostly on planetary nebula and stellar evolution.

Rob: Okay, so I see you made some recent discoveries about Buckyballs. First, what are Buckyballs?

Letezia: So Buckyballs are one of the very few molecules that are composed only of carbon in the universe. Those are big molecules that are composed of 60 carbon atoms and they are shaped as a ball with a hole inside, with a vacuum inside. The are very sturdy and very resilient and they can even carry around other atoms and molecules in their middle so they are used, for example they are used in medicine and engineering and other applications to transport chemicals around without interacting.

Rob: Why are these called “Buckyballs?”

Letezia: They are called Buckyballs because, they were discovered 25 years ago in the lab by Sir Kroto and since they are shaped like a Geodesic dome they called them Buckminster Fullerines, that’s the name of the molecule, from Buckminster Fuller which is the architect who designed the geodesic dome, so they’re not named after the inventor but the person who designed the geodesic dome.

Rob: Interesting. How did you get interested in Buckyballs yourself?

Letezia: I should say, just because we discovered them, we had these spectral observations with the Spitzer science telescope of planetary nebula within our galaxy and outside our galaxy, and we discovered them. We discovered the typical signature, the emission line signature in the spectrum that correspond to the vibrational transition of the Buckyballs. Buckyballs have been discovered in the lab 25 years ago and have been observed in meteorite material but have never been observed in any celestial objects until this year. A couple of months before our discovery they were observed in one planetary nebula and then when we got our spectra, we immediately went to see if the Buckyball signature was in our spectra and we discovered Buckyballs in an additional three planetary nebula and one extragalactic planetary nebula and that is the first extragalactic Buckyball discovery ever. This is why I became very interested.

Rob: Wow, that’s great! I understand you used Spitzer for your observations, correct?

Letezia: Yes.

Rob: Why did you have to use Spitzer for your observations?

Letezia: Well, we used Spitzer, originally we requested Spitzer for a large sample of planetary nebula in our galaxy and outside our galaxy not only to find the Buckyball signature (that was before it was even discovered) but to study the dust properties of these objects and Spitzer is able to observe in the infrared and spectral features in the infrared can put in evidence the molecular signature of the planetary nebula so that’s an ideal way to observe new molecules and known molecules in the spectrum.

Rob: So why are Buckyballs important in our understanding of planetary nebula?

Letezia: Buckyballs are important, they are not so important to understanding planetary nebula. It’s probably the other way around. Planetary nebular are important to understand Buckyballs. Because Buckyballs are Carbon rich, they are pure carbon and they have been hypothesized to be present in many stars that are rich in carbon but they have never been observed and I think they have never been observed because they have been observing the wrong stars. Once they started being looked for in planetary nebula, we found them because planetary nebula are rich in carbon (not all of them, but several of them) and the density is low enough, the gas and dust material is at a low enough density to allow the transitions of the Buckyballs to be observable.

Rob: Was there a certain mass range of stars that tend to produce Buckyballs better in their planetary nebula?

Letezia: Yeah, the is an interesting question. So, Buckyballs have been observed in planetary nebula only in some types of planetary nebula, only the carbon rich planetary nebula and it’s very likely those are the lower mass stars. Those are basically the future of our Sun, stars of the solar type.

Rob: So what is the next step in your research?

Letezia: We got now the molecular carbon, both in the Buckyball form and in other forms like amorphous carbon and dusty carbon. Now we want to determine how much atomic carbon there is in the stars and with the atomic carbon and the molecular carbon we are able to figure out what is the fraction of carbon that is formed in Buckyballs of the total carbon of the star. And to do that we need to measure the atomic carbon of the planetary nebula and to do that we need to observe in the ultraviolet regime, not the infrared. And to do that we need the Hubble this so, so we move from the Spitzer to the Hubble. In good time because the Spitzer is not available anymore (the cold Spitzer) and the Hubble is still available. There are a couple of instruments that can observe the ultraviolet spectra so that’s what we are aiming for.

Rob: Are there any space telescopes that can observe in the ultraviolet that are planned that you can use in the future?

Letezia: The ideal instrument for our obsevations, for our particular problem, is STIS on the (Hubble) Space Telescope. Instead of a future instrument, I am talking about a past instrument because STIS was active in the past and then it went dead and so for several cycles of the Hubble we weren’t able to do this. But after last cycle and this cycle, we have STIS available again so we can definitely apply for time. I don’t think there is much planned in the ultraviolet for space astronomy, not in the immediate future so for now we love to use the Hubble for as long as we can .

Rob: Thank you. Is there anything else you would like to add about your research?

Letezia: The only thing I want to add about Buckyballs and my research is that I am not a chemistry professor or a chemist so they Buckyball side of my research allowed me to talk to a lot of chemists and a lot of people who do physics and chemistry for a living instead of astronomy so it was really going outside of our usual astronomical objects and going to yet another field of science so that was very interesting to know another part of the research that is being done out thater so that was great!

Rob: Well, thank you for joining me today, Letezia.

Letezia: Thank you very much.

Rob: And I will be seeing you next month for our episode of the 365 Days of Astronomy. This is Rob Sparks from the National Optical Astronomy Observatory.

End of podcast:

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