REU Site: Research Experiences for Undergraduates in Astronomy ...

REU Site: Research Experiences for Undergraduates in Astronomy at

Cerro Tololo Inter-American Observatory

Annual Project Report (Year 1) 1 October 2011 – 30 September 2012

Submitted to the National Science Foundation

Nigel Sharp, PhD, NSF Program Officer

Pursuant to Cooperative Support Agreement No. AST-1062976

Cooperative Agreement No. AST-0809409

NOAO is operated by the Association of Universities for Research in Astronomy (AURA)

under cooperative agreement with the National Science Foundation

NATIONAL OPTICAL ASTRONOMY

OBSERVATORY

2012 CTIO REU Students and CTIO Director Dr. R. Chris Smith. From left to right, back row: Samuel Meyer and Dr. R. Chris Smith; middle row: Bezia Laderman and Clara Thomann, Front Row: Melissa Butner, Kimberly Emig, and Christine Gilfrich.

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Contents

1 ACTIVITIES AND FINDINGS ............................................................................................ 1

1.1 Research and Education Activities..................................................................... 1

1.1.1 Overview of Program Award .............................................................. 1

1.1.2 Science Program .................................................................................. 1

1.1.3 Student Activities & Local Arrangements ........................................... 7

1.1.4 Conclusions ......................................................................................... 8

1.2 Findings .............................................................................................................. 8

1.3 Training and Development ............................................................................... 10

1.4 Outreach Activities .......................................................................................... 10

2 JOURNAL PUBLICATIONS ............................................................................................. 11

3 WEB/INTERNET SITE ...................................................................................................... 12

4 OTHER SPECIFIC PRODUCTS ....................................................................................... 12

5 CONTRIBUTIONS .............................................................................................................. 13

5.1 Contributions within Discipline ....................................................................... 13

5.2 Contributions to Human Resource Development............................................. 13

5.3 Contributions to Resources for Research and Education ................................. 14

5.4 Contributions beyond Science and Engineering .............................................. 14

Research Experiences for Undergraduates in Astronomy at

Cerro Tololo Inter-American Observatory

Annual Project Report (Year 1)

1 October 2011 – 30 September 2012

Nicole S. van der Bliek, Principal Investigator

David J. James, Co-Principal Investigator

For submission to the National Science Foundation

Pursuant to Cooperative Support Agreement No. AST-1062976

30 June 2012

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1 ACTIVITIES AND FINDINGS

1.1 RESEARCH AND EDUCATION ACTIVITIES

1.1.1 Overview of Program Award

The 2012 National Optical Astronomy Observatory (NOAO) Research Experiences for

Undergraduates (REU) Program at Cerro Tololo Inter-American Observatory (CTIO) provided an

opportunity for six US undergraduate students to participate in independent, supervised research

activities in astronomy in collaboration with members of the scientific staff. The program is

supported by the rich scientific environment and research facilities of CTIO’s La Serena offices, as

well as ready access to the national observatory facilities on Cerro Tololo itself. Together, these

facilities provide a framework that introduces students to both the operations of a major observatory

and the capabilities of a variety of instruments while they are actively engaged in current

astronomical research. Building upon these resources, the program includes an introduction to

observational techniques and provides observing experiences for the participants. Furthermore, the

program offers a unique cultural opportunity for participants to live in a foreign country and work

alongside Chilean students who are doing similar research projects.

Six undergraduate students from the US, selected from a total of 17 qualified applicants from

US institutions, participated in the 2012 REU program at CTIO. Announcements were sent to over

800 college and university science and mathematics departments and career placement offices in the

US and Puerto Rico. This promotional campaign targeted the Hispanic Association of Colleges and

Universities (HACU) as well as Historically Black Colleges and Universities (HBCU). The program

was advertised on the CTIO REU program website (http://www.ctio.noao.edu/REU/reu.html) and in

the NOAO Newsletter. Advertising for the 2012 program was accomplished in August 2011, as

planned; promotional activities for the proposed 2013 program will start in July 2012.

Each student pursued a research project guided by a staff astronomer as a mentor. The REU Site

Director and Student Coordinator solicited volunteers among the CTIO, Gemini Observatory, and

SOAR Observatory scientific staff, looking for people who were willing to invest their time and

expertise to work with a student and who had projects suitable for undergraduate students carrying

out research in a 10-week program. As in previous years, there were more than enough volunteers

and projects. This year four REU mentors were CTIO staff members; SOAR and Gemini Scientists

mentored the remaining two students. In addition, one CTIO staff member and one Gemini staff

member served as mentors for the CTIO Práctica de Investigaciónes en Astronomía (PIA) program,

a CTIO-funded program for Chilean students, which is run concurrently with the CTIO REU

program.

1.1.2 Science Program

An essential component of the CTIO REU program is the opportunity students have for interaction

with scientists, not only with the observatory staff, but also with the flow of visiting astronomers

who pass through on their way to the observatory. The generally informal atmosphere at CTIO

provides a climate that promotes these interactions, which take place naturally at “Staff Tea” (every

Friday morning at 11 am the CTIO and SOAR scientific staff gather to discuss science, observatory

matters, and other topics of interest), at regular scientific colloquia, and in the public computer area

that the students share with visiting astronomers and other interns. Informal meetings with various

CTIO staff members and visiting astronomers while students were on the mountain typically

resulted in an on-the-spot introduction to an instrument or research specialty. This year during the

http://www.ctio.noao.edu/REU/reu.html

CTIO REU Award AST-1062976

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REU observing run on the 1.0-m telescope, two of the students and the REU Student Coordinator

met one of the world’s experts in exoplanets, Dr. Debra Fischer, while having dinner in the Cerro

Tololo cafeteria. This chance encounter led to a student seminar on the search for exoplanets by Dr.

Fischer when she returned to La Serena after her observing run.

Research Projects

The students’ primary focus while in Chile was to work on their individual research projects,

supervised by their respective scientific mentors, the REU Site Director, and the REU Student

Coordinator. Based on the backgrounds of the students and the suite of available projects proposed,

each student was assigned to a project and mentor that were well-matched to the student’s individual

experience level and research interests. At the end of the program, the students were asked to write a

final report on their project (precursor to a future publication). Abstracts of these papers, written by

the students and their mentors, are included in the “Findings” section. The students were encouraged

to work independently and to develop the skills and expertise to define the direction and scope of

their projects. Students who lacked research experience were given more direct guidance when

necessary. In addition, the REU Student Coordinator was available to any of the students who had

procedural, administrative, or scientific questions. The students attended weekly research group

meetings. At these meetings, the students presented their projects, their progress during the previous

week, and their plans for the upcoming week. These presentations helped them to track their

research progress and discuss issues encountered with their REU peers and mentors. These group

meetings were an excellent way to ensure that substantial and steady progress was made, while at

the same time allowing the students to practice their presentation skills. Over the course of the 10-

week program, their presentations improved dramatically, and their confidence grew equally fast.

At the end of the program, the students presented their work in a mini symposium. Each student

gave a 10–15 minute talk, which was followed by 5 minutes for questions from the audience. The

symposium took place in the AURA auditorium, on the AURA compound in La Serena, and was

attended by the CTIO, Gemini, and SOAR scientific staff and visitors. The REU and PIA students

also will present their work in the form of a poster paper at the 217th meeting of the American

Astronomical Society (AAS), scheduled for 6–10 January 2013 in Long Beach, California.

Participant support costs were provided for the students listed below. The 2012 CTIO REU

Program student research project titles are listed along with the student’s name, university

affiliation, and mentor.

Melissa Butner (Austin Peay State University)

Research Intern to Dr. Eric Mamajek (CTIO)

Project Title: “Spectral Classification of Members of a Candidate Cluster in Telescopium”

Kimberly Emig (University of Hawai’i at Hilo)

Research Intern to Dr. Catherine Kaleida (CTIO)

Project Title: “Simulated Star Clusters with MASSCLEAN: Testing a Stellar Grouping Selection

Method”

Christine Gilfrich (St. Mary’s College of Maryland)

Research Intern to Dr. Tiago Ribeiro (SOAR)

Project Title: “Orbital Period of WD + M Binaries”

FY12 Annual Project Report (Yr 1)

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Bezia Laderman (New York University)

Research Intern to Dr. Timothy Abbott (CTIO)

Project Title: “Finding Periodicities CP Eri”

Samuel Meyer (Harvard College)

Research Intern to Dr. Peter Pessev (Gemini)

Project Title: “Expanding Integrated-Light Photometry of LMC Star Clusters in the NIR to

Extremely Young Ages”

Clara Thomann (Macalester College)

Research Intern to Dr. David James (CTIO)

Project Title: “A Photometric and Spectroscopic Survey of Solar-type Stars in Open Cluster

Collinder 70”

Weekly Student Seminars

Apart from the official CTIO colloquia, the students attended a seminar series especially designed to

reflect their needs and interests. The seminars covered a broad range of topics, both observational

(“Intro to Observational Astronomy”) as well as more theoretical (“Tutorial on Adaptive Optics”).

Additionally, several general seminars and discussions were scheduled for the students. For

example, CTIO Director Dr. Chris Smith welcomed the students to Chile with a presentation on

CTIO, NOAO, and AURA, and Deputy Director Dr. Nicole van der Bliek gave an introduction to

life in La Serena. The seminars were given from 16 January through 22 March 2012 by the CTIO

and Gemini scientific staff—and one by visiting astronomer Dr. Fischer—once a week, usually on

Mondays from 2:00–3:00 pm The list of topics and speakers from the 2012 Student Seminar Series

follows below:

Dr. Chris Smith (CTIO Director): “Welcome to CTIO”

Dr. Nicole van der Bliek (CTIO Deputy Director): “Welcome to Chile”

Dr. Alistair Walker (CTIO): ”RR Lyrae Stars”

Dr. Karianne Holhjem (SOAR): “Image Reduction”

Dr. David James (CTIO): “Intro to Observational Astronomy”

Dr. Debra Fischer (Yale University): “Searching for Earths around Alpha Centauri”

Owen Boberg (New Mexico State Univ./CTIO): “Creating Color Images: Making Astronomy

Pretty”

Dr. Malcolm Smith (CTIO): “The UNESCO World Heritage ‘Windows to the Universe’: A

Multidisciplinary Concept to Help Control Light Pollution”

Dr. Andrei Tokovinin (CTIO): “Challenges of Multiple Stars”

Dr. Andrei Tokovinin (CTIO): “Tutorial on Adaptive Optics at CTIO”

Dr. Mischa Schirmer (Gemini): “Data Reduction with Theli”

Dr. Peter Pessev (Gemini): “Gemini Observatory”

Guillermo Cabrera (Universidad de Chile/LSST): “Astroinformatics”

Dr. Catherine Kaleida (CTIO): “Applying for Graduate School”


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Observing on Cerro Tololo

As part of the CTIO REU program, the students observed on Cerro Tololo using the SMARTS

Consortium 1.0-m telescope (Figure 1). The objective of the observing run was to introduce the

students to observing techniques and allow them to sample different methods of observing. The

observing time, eight nights in total, was requested via the regular NOAO Time Allocation

procedure (program ID: 2012A-0594). This proposal was ranked highly by the Telescope Allocation

Committee, receiving a grade of 9 out of 10, where 10 was the highest grade achievable. These eight

nights corresponded to two observing nights for each group of two students.

For the 2012 program, the student observing plan included observations of RR Lyrae variable

stars and Lyman Alpha Blob (LAB) candidates (objects important to understanding galaxy

evolution), in collaboration with Dr. Andrew Layden and Tyler Anderson of Bowling Green State

University, and Dr. Rolf Jansen and Paul Hegel of Arizona State University, respectively. A portion

of the observing time was also left open for the students to observe objects of their own choosing.

The students imaged Southern Hemisphere galaxies, star clusters, and nebulae, as well as confirming

a supernovae candidate (published in an online supernova circular at:

http://www.cbat.eps.harvard.edu/iau/cbet/003000/CBET003014.txt).

Figure 1: Group photo of the 2012 CTIO REU/PIA program students with Cerro Tololo in the background taken from Cerro Pachón. From left to right: Melissa Butner, Kimberly Emig, Samuel Meyer, Catherine Kaleida (REU Student Coordinator), Christine Gilfrich, Mayte Alfaro (PIA student), Bezia Laderman, Odette Toloza (PIA student), and Clara Thomann. Photo by Peter Pessev (Gemini).

http://www.cbat.eps.harvard.edu/iau/cbet/003000/CBET003014.txt


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Observatory Field Trips

The REU grant provides funding for a three-day field trip to a site of astronomical significance,

which allows the students to get a taste of other observatories and get acquainted with their unique

telescopes, instruments, and operations. For the 2012 CTIO REU program, the students visited

observatories on Cerro Paranal, Cerro Pachón, Cerro Las Campanas, and Cerro La Silla.

Cerro Paranal is the site of the European Southern Observatory (ESO), one of the premier

astronomical sites in the world, and home to the Very Large Telescope (VLT). The VLT is an array

of four 8.2-m telescopes that operate either as stand-alone telescopes or combined through an

interferometric network to act as one large aperture. The observatory is a three-hour drive from

Antofagasta in Northern Chile, through some of the most arid (and beautiful!) terrain on Earth.

While at Cerro Paranal, the students toured the telescopes and observatory facilities, and over lunch

they met a former CTIO REU student Dr. Gabriel Brammer (2001 CTIO REU program alumnus).

Dr. Brammer is currently a postdoctoral research fellow at ESO Chile, working at Paranal

Observatory. He shared the story of his journey from being a CTIO REU student to an ESO Fellow,

and told the students how the REU program helped him to get to where he is today.

Cerro Pachón is home to two telescopes: the 8.0-m Gemini Telescope, and the 4.2-m SOAR

Telescope. Proximity to CTIO, both geographic and institutional, allowed for easy arrangement of a

site tour for the 2012 REU students. Dr. Peter Pessev (Gemini) and Dr. Tiago Ribeiro (SOAR) led

exciting tours for the REU/PIA students, the REU Student Coordinator, and one Gemini student,

introducing the various instruments and modes of observing at each telescope (Figure 2).

Figure 2: The 2012 CTIO REU/PIA program students in front of the Gemini 8-m mirror. From left to right, front row: Felipe Et (Gemini student), Bezia Laderman, Samuel Meyer; back row: Odette Toloza (PIA student), Mayte Alfaro (PIA student), Clara Thomann, Kimberly Emig, Melissa Butner, Catherine Kaleida (REU Student Coordinator), and Christine Gilfrich.


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This year’s REU and PIA students were very interested to see as many of the major

observatories in Chile as possible during their time here. Thus, the REU Student Coordinator also

arranged for tours of the observatory facilities on Cerro Las Campanas (Las Campanas Observatory)

and Cerro La Silla (ESO’s La Silla Observatory) with sack lunches and transportation paid for by

the students. As La Silla and Las Campanas are relatively near (~2 hours driving) La Serena, this

was an affordable expense and seven of the eight REU/PIA students chose to attend.

Through visiting many different observatories, the students were able to learn about the various

types of telescope designs and their benefits and detriments.

Other Field Trips

Maintaining dark skies for astronomical research and for the general public is an important issue for

future astronomers, as the increase of inefficient lighting and light-emitting diode (LED) billboards

threatens the night skies more every year. To illustrate this point, the students visited the summit of

Cerro Grande, the highest peak near the city of La Serena. On Cerro Grande, they measured the light

pollution from the city, and they honed their astrophotography skills under the guidance of Dr.

Malcolm Smith (CTIO). Using a Sky Quality Meter, they measured the sky brightness and

quantified the difference between the sky brightness in the direction of La Serena and the opposite

direction. Former CTIO Director Dr. Malcolm Smith is a skilled amateur astrophotographer, and he

taught the students how best to use their cameras to capture images of the night sky. The students

took many beautiful shots of the southern sky that evening (Figure 3).

During their time in Chile, the students visited two universities in the La Serena/Coquimbo area:

Universidad de La Serena (ULS), and Universidad Católica de Norte. The purpose of these visits

was to facilitate more interactions between the US students and Chilean students and professors, as

Figure 3: From atop Cerro Grande, REU/PIA students observe the planet Venus and measure the light pollution from the cities of La Serena and Coquimbo. Photo by REU student Clara Thomann.


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well as to supplement their cultural and environmental education while in Chile. Mayte Alfaro, a

2012 CTIO PIA participant and ULS student, arranged a meeting with the astrophysics research

group at ULS. The students learned about the research being conducted at the university and

attended an astronomy seminar, “Stars Outside Galaxies,” by Dr. Sergio Torres Flores.

The REU/PIA students also paid a visit to the Marina Biology department at the Universidad

Católica de Norte in Coquimbo, a neighboring city to La Serena. At the Marine Biology department,

Professor Martin Thiel introduced the group to the “stars of the sea,” giving everyone a tour of the

fish and marine life research facilities and the university’s public aquarium. The students then rolled

up their pant legs and explored the rocky coastline next to the university, using the knowledge they

had just gained to find and identify the organisms. In return, Professor Thiel and his Marine Biology

students were invited to the La Cancha Summer Star Party, organized by CTIO, to see the stars in

the sky. The students enjoyed this exchange tremendously, and there will be a similar visit with next

year’s students.

1.1.3 Student Activities & Local Arrangements

The six US REU students, together with the two Chilean PIA students, shared a fully furnished

house on CTIO’s La Serena compound, for which they were charged a modest rent. This

arrangement maximized the cross-cultural interaction for all of them. The students have consistently

rated this cultural component of the CTIO REU/PIA program to be a successful and important part

of their overall experience. The students were provided with a workspace and a computer in the

public computer area of CTIO’s La Serena facility. Each student had a reserved place in the

computer room and was guaranteed access to a computer previously purchased through this REU

grant. The use of the public computer room promoted the opportunity to interact with visiting

astronomers, several of the technical staff, and other interns. As a result, the students were well

integrated in the daily work and social activities of the Observatory.

The REU and PIA students and the REU/PIA program in general received excellent

administrative support from the staff in Chile and the NOAO Central Administrative Services (CAS)

staff in Tucson. The students encountered no problems with the logistical arrangements during their

time in La Serena.

Program Travel

For travel to/from Chile, and for the domestic flight to Antofagasta for the trip to Cerro Paranal, in-

house personnel were used to coordinate all REU logistics with a local, Chilean travel agency. In the

past, this has proven to be the most reliable and often cheapest option. The on-site availability of this

logistical support enables easy troubleshooting should any problems arise. A travel agent in Tucson

with institutional ties to NOAO was used for 2011 REU student travel to the January 2012 AAS

conference. The travel arrangements for that 2012 AAS meeting were done in a timely and

organized manner, and the plan is to continue this relationship for the 2013 AAS conference and in

the future.

Student travel to Chile this year was subject to a delayed flight in Dallas that resulted in having

to spend the night in hotels in Dallas and Santiago before finally arriving in La Serena. This

situation reconfirmed that it is important that the REU Student Coordinator (who was returning from

the 219th AAS meeting) accompany the REU students on their flight from the US to Chile. The

travel to Chile is often the first international flight for the majority of the students and is an

unfamiliar experience for all of them. Support for transportation and accommodation in La Serena

by local CTIO employees was outstanding.


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1.1.4 Conclusions

After 17 years of successful operations, the CTIO REU program continues to provide a positive

educational experience for all participants, not only in learning about astronomy, but also about the

nature and operation of a national observatory, the future and function of the national and

international astronomy facilities, and how one lives and works in a multicultural setting. Each year,

an evaluation questionnaire is distributed to the REU and PIA students by email. They are asked to

complete the questionnaire and are assured that the results will be considered anonymously. An

online form was created that ensures the anonymity of the students. The main purpose of this

evaluation process is to help determine what parts of the REU program curriculum worked well or

poorly, in order to improve the program in following years. It also provides a measure of the impact

of the program on the students and the degree to which they enjoyed their Chilean REU experience.

When asked, “How do you think the REU/PIA experience has changed you and your outlook on

astronomy and astronomical research?” in the online evaluation, one student answered, “[M]y #1

choice for grad school will be an astrophysics department.” The 2012 program was a positive

educational experience for all of the students, not only in learning about astronomy, but also about

the nature of a national observatory, about the future of the national and international astronomy

facilities, and about how one lives and works in a multicultural setting. The students’ impressions of

the program and their reactions to the experience were extremely positive.

1.2 FINDINGS

At the end of the program, each student presented the results of their 10 weeks of research at a

Student Symposium held in the AURA Lecture Hall on the AURA campus in La Serena. Scientific

staff members of CTIO, SOAR, and Gemini attended this symposium. Each student gave a 10- to

15-minute presentation followed by 5 minutes of questions from the audience. The following are

abstracts of the REU/PIA students’ research projects, written by the students and their mentors:

Melissa Butner: “Spectral Classification of Members of a Candidate Cluster in Telescopium”

We characterize whether the spectral types, colors, magnitudes and astrometry for a sample of

stars in the constellation Telescopium are consistent with constituting a true star cluster. The

candidate cluster was first noticed by E. Mamajek as an excess of A-type stars with similar proper

motions in the HD catalog. Based on the number of A-type stars seen, the candidate cluster could be

surprisingly rich, and hence it would surprising that it had remained undetected until now. We

derived accurate spectral types for these stars using optical spectra from the SMARTS 1.5-m

telescope at Cerro Tololo and comparing them to a grid of MK spectral standards. Our initial

analysis is suggestive that a real group may exist, at distance 400 pc and age 630 Myr (similar to the

Hyades).

Kimberly Emig: “Simulated Star Clusters with MASSCLEAN: Testing a Stellar Grouping

Selection Method”

An accurate selection method for identifying and characterizing stellar groupings in nearby

galaxies is essential for determining the size scales of stellar clustering. By generating fields of

simulated star clusters with known ages, masses, sizes and metallicities, the accuracy of such a

selection algorithm can be analyzed. Using code developed in IDL, the Massive Cluster Evolution

and Analysis Package (MASSCLEAN) and SkyMaker have been used to simulate clusters of

varying ages, masses, and sizes with properties tuned to mimic stellar groupings found in Hubble

Space Telescope, Wide Field Camera 3, and F336W images of the dwarf irregular galaxy NGC


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4214. The point spread function (PSF) has been modeled using Tiny Tim. An archive of simulated

star cluster fields with varying numbers of clusters (∼10–200) and randomly selected positions

within the field has been created. Primarily we examine the number of clusters generated versus the

number retained and discuss the limitations of the selection algorithm in light of these results. A

reliable selection method is imperative for studying the size scales and disruption time of stellar

groupings in nearby galaxies and the relationship between the properties of stellar groupings and

their host galaxies.

Christine Gilfrich: “Orbital Period of WD + M Binaries”

Studying WD + M binaries can give insight into the evolution of cataclysmic variables because

of their presence in CVs’ evolutionary process. SDSSJ0256 is a WD + M binary found in the

SLOAN Digital Sky Survey which has not previously been studied; the SLOAN data does not

include an orbital period. I used spectroscopic data from the Goodman Spectrograph on SOAR

collected at various dates to find the changes in H-α emission lines from the main sequence star

throughout its orbit. From these wavelengths, I calculated the velocities, which were analyzed using

a Lomb-Scargle periodogram to find SDSSJ0256’s orbital period to be 2.6 hours (with a false-

positive probability of 10%), its radial velocity semi-amplitude to be 32 ± 5 km/s, and its gamma

velocity to be 19 ± 4 km/s. We compared this to other possible periods from the Lomb-Scargle

periodogram using their power, false-positive probability as outlined by Frescura et al (2008), and χ2

testing. Although the fit to our data is far from perfect, the phase diagram shows a reasonably close

trend. As such, this study points to an orbital period of approximately 2.6 hours for SDSSJ0256, to

be made more certain by additional observations.

Bezia Laderman: “Finding Periodicities CP Eri”

Between January 27 and January 29 the IBWD (interacting binary white dwarf) CP Eri was

observed from the CTIO 0.9m during a period of quiescence. The data was reduced, light curves

were created by comparing CP Eri to other non-variable stars in the field, and periodograms where

generated from the light curves. An unexpected signal corresponding to a 32-minute periodicity was

found, but the expected signal from previous studies at about 29 minutes was not seen, prompting

the need for follow up observations during periods of quiescence.

Samuel Meyer: “Expanding Integrated-Light Photometry of LMC Star Clusters in the NIR to

Extremely Young Ages”

The goal of this project is to extend the sample of LMC clusters with integrated-light

photometry available to the limits set by the depth of the 2MASS Atlas Images. Using recently

published new catalogs of Magellanic Clouds clusters ages, we are focusing mainly on the clusters

populating the parameter space between 250 and 800 Myr. Such clusters are severely under-

represented in the samples available so far. There are two main reasons for this: (i) samples so far

were focused on clusters with reliable age and metallicity determinations; (ii) the masses (hence

luminosities) of the Magellanic Clouds clusters are decreasing with decreasing age. Clusters

younger than ~1 Gyr are much more challenging from an observational point of view and more

difficult for analysis. To tackle the problem we are adopting a statistical approach, analyzing

hundreds of objects populating the selected age interval. Our data reduction and analysis were

focused on obtaining reliable integrated-light magnitudes and error estimates in J, H, and Ks

2MASS filters. The final sample consisted of 30 objects, effectively tripling the number of objects

with integrated-light measurements available in this age interval. The depth of the imaging data

turned out to be the main limitation. We found that particular care needed to be taken in order to


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mitigate the effects of the stochastic fluctuations in the stellar population. The results of the present

study are crucial for our understanding of the LMC star clusters system. They are paving the road

for the deeper Magellanic Clouds surveys that are going to be available in the future. Considering

that the Magellanic Clouds are invaluable astrophysical laboratory affecting many fields of the

modern astronomy, surely this new dataset will play an important role beyond its original purpose.

We are also considering expanding the dataset using dedicated observations in the future.

Clara Thomann: “A Photometric and Spectroscopic Survey of Solar-type Stars in Open Cluster

Collinder 70”

Presented in this review are preliminary results regarding cluster membership and age via

photometry and fiber spectroscopy observations of 70 low-mass stars in open cluster Collinder 70.

The targets were originally selected from color-magnitude diagrams, and subsequently refined by

using low-resolution spectroscopy to determine the presence of H-alpha and Li I. The members of

Collinder 70 were finalized by a measurement of lithium equivalent widths via Gaussian fitting and

direct integration, concluding with a list of 23 probable members. Model isochrones from Baraffe et

al. (2002) evolutionary models are overlaid on a lithium equivalent width and color plot with target

stars, suggesting that Collinder 70 is less than 50 million years old. Other lines of evidence—low

mass stars with un-depleted levels of lithium, indications of giant-like pre-main sequence stars, and

infrared excess—indicate that the cluster is younger, but the age cannot be constrained without

further observations and more lithium-rich members.

1.3 TRAINING AND DEVELOPMENT

The main goal of the CTIO REU program is to provide an opportunity for students to carry out a

research project, supervised by one of the staff astronomers at CTIO, SOAR, or Gemini and by the

REU Student Coordinator. At the end of the program, the students report on their work in the form

of a written report and short presentation. The students were encouraged to work independently, but

those who lacked research experience were given more direct guidance when necessary by their

mentor or the REU Student Coordinator. The CTIO summer students also had the opportunity to

observe on Cerro Tololo, using the CTIO/SMARTS 1.0-m telescope. The objective of the observing

run was to introduce the students to observing techniques and to allow them to sample different

methods of observing, as dictated by various projects that had different scientific objectives. Thus,

the students experienced the three main tasks of a professional observational astronomer:

observation, analysis of results, and subsequent reporting and publication.

Furthermore, the student selection committee aims to select not only the best students, but also

the students who will benefit the most from the CTIO REU program. For example, the committee

ensures that the students come from a mix of large and small astronomy departments. In addition,

the students are selected to have a wide range of abilities and experience to encourage peer

mentoring. The students obtain teaching skills from answering one another’s questions in their area

of expertise (i.e., computing, telescope operations, etc.), and they gain useful tools and information

from the knowledge of their fellow students.

1.4 OUTREACH ACTIVITIES

One of the highlights of this year’s program was the students’ participation in the Summer Star Party

organized by the Education and Public Outreach (EPO) team at CTIO. The Summer Star Party is a

free event offering sky tours of the night sky, viewing of astronomical objects with small telescopes,


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and astronomy-related activities for children. The Star Party is open to the families and friends of all

observatory staff members (including custodians, human resource staff, mechanical shop employees,

etc.). It is held at a dark-sky site called “La Cancha” that is along the road to Cerro Tololo and Cerro

Pachón and away from the city lights of La Serena. The telescopes on Cerro Tololo are clearly

visible from the La Cancha site, and provide a spectacular setting to observe the Southern skies. The

students were each given a small telescope, called a Galileoscope, which they assembled themselves

and learned to use in a mini-workshop given by the EPO team a few days before the event. With

these Galileoscopes, the students assisted the CTIO EPO team with showing stars, planets, and star

clusters to the attendees of the event. At the end of the event, the students experimented with the

night photography skills they obtained while on Cerro Grande and posed for a photo taken by a

fellow Star Party participant, Hérnan Stockebrand (Figure 4).

2 JOURNAL PUBLICATIONS

Over 100 publications have resulted from collaborations with the REU students since the beginning

of the CTIO program in 1995. An updated list of publications is available at a webpage on the REU

CTIO website (http://www.ctio.noao.edu/noao/content/publications-related-ctio-reu-projects). The

following is a list of recent publications by CTIO REU students. These include publications by the

2011 REU cohorts. The 2012 REU students will present their work at the January 2013 meeting of

the AAS. Students’ names are in boldface text.

Figure 4: The CTIO REU and PIA students pose for a photo with the night sky above Cerro Tololo after participating in a Star Party event for the observatory families and friends at the La Cancha site. From left to right, front row: Bezia Laderman, Catherine Kaleida (REU Student Coordinator), and Clara Thomann; back row: Samuel Meyer, Melissa Butner, Christine Gilfrich, Odette Toloza (PIA student), Mayte Alfaro (PIA student), and Felipe Et (Gemini student). Photo by Hernán Stockebrand.

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Accetta, K. & Kunder, A. 2011, BAAS, 43, #150.01, “RR Lyrae as Structural Tracers for the

LMC”

Banados, E., Hung, L.W., De Propris, R., West, M. 2011, BAAS, 43, #149.17, “The Faint End

of the Galaxy Luminosity Function in A1689: A steep Red Faint End Upturn at z = 0.18”

Basarab, B. 2012, BAAS, 44, #145.04, “The Lick Index Calibration of the Gemini Multi-

Object Spectrographs”

Carney, M.T. 2011, BAAS, 43, #338.03, “Phase-Resolved Cyclotron Spectroscopy and

Polarimetry of HU Aquarii”

Gifford, D., Miller, C., Harrison, C., Kao, M. 2011, BAAS, 43, #408.16, “The Caustic Mass—

Optical Richness Relation for C4 Galaxy Clusters”

Goldwell, G., Salois, A., Soechting, I., Smith, M. 2011, BAAS, 43, #335.29, “Sampling Studies

of Quasars, Radio-loud Galaxies, & Radio-quiet Galaxies—Searching for the Cause of Radio

Emission”

Hung, L.W., Banados, E., de Propris, R., West, M. J. 2011, BAAS, 43, #149.02, “The Galaxy

Alignment Effect in Abel l 1689”

Kao, M., Harrison, C. 2011, BAAS, 43, #149.16, “Caustic Mass Estimate of Abel l 370”

Sayres, C.C., Subasavage, J.P., Bergeron, P., Davenport, J.R.A., AlSayyad, Y., and Tofflemire,

B. M. 2012 AJ, 143,103, “A Multi-survey Approach to White Dwarf Discovery”

Sayres, C.C., Subasavage, J.P., Bergeron, P., Davenport, J.R.A., AlSayyad, Y. 2011, BAAS,

43, #341.01, “Multi-survey and LDA Techniques for Cool White Dwarf Discovery”

3 WEB/INTERNET SITE

The CTIO REU Program website can be found at http://www.ctio.noao.edu/REU/reu.html. On this

website, potential students can find information about the program, and current and past students can

post the results of the research they worked on while at CTIO. The website also contains a page that

lists the publications related to work carried out during the CTIO REU summer student programs,

going back to the start of the CTIO REU program in 1995. Furthermore, the website has various

photo-galleries, which give a good impression of the programs, and the start of an English-Spanish

Astronomy Dictionary, developed by the 2012 REU/PIA group.

4 OTHER SPECIFIC PRODUCTS

As part of the Weekly Research Meeting, the REU and PIA students participated in an Astronomy

Language Exchange. At the beginning of each meeting the students came up with astronomy-related

technical terms in English to translate to Spanish, and from these suggestions compiled the

beginnings of an English-Spanish Astronomy Dictionary. The intent is to continue this practice in

future year’s REU and PIA programs with the aim of creating a comprehensive English-Spanish

Astronomy Dictionary to post on the Web for public use.

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5 CONTRIBUTIONS

5.1 CONTRIBUTIONS WITHIN DISCIPLINE

The main goal of this program is to allow students, mainly astronomy and physics majors, but also

the occasional math major, to participate in research, get hands-on experience in observing, work in

a research institute (non-university based, for a different perspective), experience the international

nature of astronomy (working in Chile, at an international observatory) alongside Chilean students.

The students directly contribute to making new discoveries in the field of astronomy and frequently

publish these results in peer-reviewed journals. A summary of the specific astronomical discoveries

of the 2012 REU students can be found in the “Findings” section of this document.

5.2 CONTRIBUTIONS TO HUMAN RESOURCE DEVELOPMENT

The goal of this program is the development of young astronomers who will be the future scientists.

Seventeen applications for the 2012 CTIO REU program were received. Of these applicants, 71%

(12 out of 17) were women and 29% (5 out of 17) were men. As the majority of our applicants were

women, 67% (4 out of 6) of the students selected for the 2012 program were women and 33% (2 out

of 6) were men. As this year’s applicants were not asked to disclose their race/ethnicity, there can be

no report on the racial diversity of the applicant pool.

Of the six selected students, five where White/Caucasian (not Hispanic/Latino) and one was

White/Caucasian and Hispanic/Latino (note that as of the 2010 US Census, Hispanic/Latino is no

longer considered a race, but continues to be a group underrepresented in the sciences (for more

information, see http://2010.census.gov/2010census/about/interactive-form.php, and

http://www.nap.edu/catalog.php?record_id=12984). Clearly, the underrepresentation of minorities

in the sciences is reflected in the 2012 REU cohort. We will continue our efforts to advertise heavily

at historically minority-serving institutions and conferences in the US. One of the 2012 students,

Kimberly Emig, will be presenting her project from the CTIO REU program at the National

Conference of the Society for Advancement of Chicanos and Native Americans in Science in

October 2012, and there is hope that other students at this conference will be inspired to apply after

seeing her work and hearing her enthusiasm for the CTIO REU program.

Geographically, the applicants were from 13 states in the US: 6 from the South, 3 from the

Midwest, 2 from the Northeast, 1 from the West, and 1 from the Pacific (Hawai’i). In past years,

there has been a smaller proportion of applicants from the South and Midwest, and it is gratifying to

see that this year the advertising efforts for the program are reaching those parts of the country that

have been underrepresented in our program alumni.

The home institution size of the accepted applicants also was tabulated: 83% (5 out of 6) were

from schools with fewer than 10,000 enrolled undergraduates. The CTIO REU program continues to

be committed to providing astronomy research experiences to students whose home institutions

cannot provide them with the same opportunity.

The CTIO REU groups are chosen based on merit as well as how much they will benefit from

the program, however, an effort is made to have groups that are balanced in gender and include

students from underrepresented minorities. As such, the CTIO REU program is directly contributing

to broadening participation in the science, technology, engineering, and mathematics (STEM)

disciplines.

http://2010.census.gov/2010census/about/interactive-form.php

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5.3 CONTRIBUTIONS TO RESOURCES FOR RESEARCH AND EDUCATION

The 10-week REU program includes lectures by observatory staff who cover a range of topics. The

students visit neighboring observatories (SOAR and Gemini South) as well as the more northern

observatories (Las Campanas and ESO with the La Silla Observatory site and the Paranal

Observatory site).

5.4 CONTRIBUTIONS BEYOND SCIENCE AND ENGINEERING

One of the unique characteristics of the CTIO REU program is that it offers the opportunity to live

and work in an international setting at an observatory in a foreign country. The US students work

alongside Chilean students who participate in the parallel PIA program, and the cultural experience

these young astronomers obtain is as invaluable to their growth and maturation into successful

astronomers as the research projects themselves. When asked in the program evaluation to give

advice to future year’s students, one 2012 REU student stated, “…be prepared to learn things you

didn’t expect. I would say that I learned more about myself and how interact with others.”

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