The Role of Small Telescopes in Modern Astronomy

October 14-October 15, 1996

Talk Abstracts

The Role of Small Telescopes in the Study of Young Stellar Clusters, Star Formation, etc.

Lynne Hillenbrand
University of California, Berkeley

The origin of stellar masses (and the initial mass function) and the origin of stellar angular momenta (and the distribution with mass of initial angular momenta) represent two fundamental, unsolved problems in stellar astronomy. Progress toward their solution requires developing a census of stellar populations in young clusters characterized by a range of initial conditions and environments. To derive stellar properties (masses, ages, rotational velocities), both photometric and spectroscopic observations of large samples of stars are needed. This necessitates the synthesis of information collected from a variety of telescopes with apertures in the 1m-4m range. I will illustrate the importance of access to such a complement of facilities by discussing the results of a recent investigation of the stellar population in the Orion Nebula Cluster (ONC). This study makes use of optical photometry, infrared photometry, and both high- and low- resolution optical spectroscopy for stars spanning a dynamic range in apparent magnitude of ~20 mag. The ONC has formed stars of all masses from < 0.1-50M and is < 1 Myr in age; the ability to derive individual stellar masses, ages, and rotational velocities, for a statistically significant sample of stars, allows direct measurement of initial mass, age, and rotational velocity distributions. In turn, the statistics provided by the ONC database allow us to use this region to inform our similarly motivated studies of stellar populations in young clusters spanning wide ranges in size, stellar density, environmental conditions, and eventually age. Small telescopes are critical to enabling these types of fundamental investigations.

A more detailed outline of this talk is available.

The Macho Project: Revealing Galactic Dark Matter and Surveying the Time Domain in Astronomy with a 50" Telescope

Kem H. Cook

C. Alcock, D. Alves, S. Marshall, D. Minniti

R. A. Allsman

T. S. Axelrod, K. C. Freeman, B. A. Peterson, A. W. Rodgers

A. C. Becker, C. W. Stubbs
CfPA/U Washington

D. P. Bennett

K. Griest, J. Guern, M. J. Lehner

M. R. Pratt

P. J. Quinn

W. Sutherland

D. L. Welch
McMaster (The MACHO Collaboration)

The Macho Project is using both Magellanic Cloud and Milky Way bulge stars as sources to search for the gravitational microlensing signature of baryonic dark matter in the Milky Way's halo. These fields provide millions of relatively bright, resolved stars with lines of sight through much of the halo. This project requires a wide field system, and only a moderate aperture. The MACHO Project has the dedicated use of the Mt. Stromlo 1.27-m telescope. A prime focus corrector with an integrated beam splitter produces simultaneous, two color images on two 4096x4096 CCD arrays. In the past four years, we have collected about 50,000 0.5 square degree, dual color CCD images. A preliminary analysis of a photometry database spanning our first two years for about 10 million stars in the LMC and 12 million stars in the bulge has been been completed. We have detected about 10 microlensing events toward the LMC, and 100 microlensing events toward the bulge. These discoveries suggest a significant fraction of the Milky Way's halo is composed of Massive Compact Halo Objects (Machos) and that the Milky Way is a barred spiral with the bar oriented close to the line of sight to the galactic center. We have also cataloged about 40,000 variables stars in each of these directions. The combination of wide area coverage, dense temporal sampling, and uniformity of data product found in the Macho survey is yielding a new perspective on stellar pulsation physics, chemical and dynamical evolution of the observed populations, and may solve the discrepant RR Lyrae and Cepheid distance scales.

Amateurs and Mentors

Leif J. Robinson
Sky & Telescope

Hundreds of amateurs have telescopes 0.2-m to 0.5-m in aperture that are equipped with CCDs and other high-sensitivity, low-noise accessories. They also have the computing power to carry out thorough data analysis.

In the near future, small telescopes may disappear from national facilities and, because of poor job prospects, fewer students may choose astronomy as a career. Knowledgeable, equipment-rich amateurs could make excellent collaborators with professionals. In fact, many amateurs may desire to work directly with a professional, one-on-one. Such interaction is now exceedingly easy thanks to modern communications.

Except for photon starvation, amateurs doing ordinary science are not badly limited by technology. However, they are limited by a dearth of fresh ideas. Many amateurs are unable to choose a promising research road simply because they don't have enough background. So I propose that some organization, such as the AAS, AAVSO, ASP, or IAPPP, should begin a "Mentoring Connection." It's goal should simply be to put good scientists in touch with good amateurs. Philosophically, I believe any such program should be guided by the principle of true partnership. The professional should encourage the amateur to get as deeply involved as his or her inspiration, time, and ability permits.

Traditional fields of research include astrometry, imaging, and photometry. Yet there is no reason why polarimetry, spectroscopy, and spectrophotometry are beyond the capability of amateurs, especially if modestly supported by training and equipment.

The Role of the 0.6 m Telescope at Van Vleck Observatory in Astronomy Education at Wesleyan University

William Herbst (
Astronomy Dept., Wesleyan University

I review the variety of ways in which the 0.6 m telescope on the campus of Wesleyan University contributes to astronomy education. Wesleyan is representative of smaller institutions with only one or a few astronomers and an emphasis on undergraduate education. Institutions like Wesleyan are important contributors to the pool of applicants for graduate study in astronomy. The value of this telescope to our programs may be summarized as follows: 1) enhancing general interest, knowledge and support of astronomy by providing opportunity for many students, some of whom will rise to leadership positions in society, to share the excitement of the field, 2) teaching science to undergraduates in an exciting way using actual measurements for lab purposes, 3) attracting talented new people into the field, 4) training our advanced students to be able to use telescopes at any observaotry, and 5) supporting some research programs (monitoring T Tauri stars and supernovae, in our case) that cannot be carried out with shared facilities because of the time demands. A brief review of results obtained from the T Tauri monitoring program over five years is given. The important discovery of a bimodal distribution of rotation periods in the Orion Nebula Cluster is discussed. Smaller institutions need at least two things to continue to be effective members of the astronomical community. They are: 1) some support for instrumntation (e.g. CCDs) for the campus telescopes, such as is provided by the NSF-ILI program, and 2) the possibility to compete for observing time at world-class facilities, on a science-first basis. The latter item has been provided for many decades by NOIRLab at optical wavelengths. It is now threatened, and its loss would prove disastrous to Wesleyan and institutions like ours without the resources to provide alternate observational capabilities to our staff and students.

Back to the Future: The Southeastern Association for Research in Astronomy (SARA) Observatory at Kitt Peak and the Future of Small Telescopes at National Sites

Terry D. Oswalt
Florida Tech / SARA

In 1995 the Southeastern Association for Research in Astronomy (SARA), a consortium of the Florida Institute of Technology, East Tennessee State University, University of Georgia, Valdosta State College and Florida International University recommissioned a 0.9-m telescope formerly operated by NOAO. The SARA Observatory (below) is located at a new site on Kitt Peak near Mercedes Point, just west of the Burrell Schmidt telescope. In this talk we outline the status of our project, and the benefits such university collaborations offer in these times of declining numbers of publicly available small research telescopes and reduced employment expectations in astronomy.


Eighteen Ph.D. astronomers at the five SARA institutions now use our facility at Kitt Peak and bring students to the observatory on a regular basis. Current SARA research interests span all areas of observational astronomy (see individual departments' homepages for details). Each institution is guaranteed a fraction of the available observing time proportional to its financial investment. Observing time is available to non-SARA astronomers either by direct collaboration or on a contractual basis. This research facility has had an unexpected but welcome side effect: each SARA member institution has hired at least one new astronomer since the consortium was formed, a non-trivial contribution to the astronomical employment picture.

The SARA telescope is equipped with a four-port instrument selector which allows use of several instruments during a given night of observation. It is already fully computer-controlled. Over the next several months we will begin experimenting with remote robotic scheduling of the telescope via the Internet, with a goal of making the data gathered by it available to classroom students, as well as to on-site observers. Through optimized and queued scheduling we hope to achieve a much higher level of productivity and telescope access than could be achieved by the traditional scheduling methods used at most observatories. This is particularly important to faculty like ours, who have heavy teaching responsibilities and cannot travel to the Observatory more than a few times per year. Mostly because the telescope is not yet fully subscribed, but also to provide a sound financial base for instrument improvements and the inevitable gradual increase in operating and maintenance costs, SARA plans to add one or two new institutional members in the near future.

Undergraduate student involvement in research is one of SARA's primary interests. With funding provided by the NSF in 1995, SARA established the first multi-institution Research Experiences for Undergraduates site. SARA recruits student interns from around the U.S.; each spends the summer working with a faculty mentor at one of the SARA institutions. In addition to two multi-day workshops which bring all participants together at one of the SARA schools, each intern plans and executes an observing run at the SARA Observatory in Arizona. At summer's end, each student submits a summary of his/her research results, which is published in the IAPPP Communications.

SARA intends to take an increasing role in helping to represent the interests of astronomers who need the smaller telescopes to conduct their research. As a first step, we have recently agreed to be host institution for the North American Small Telescope Cooperative (NASTeC). The purpose of NASTeC is to call the general astronomical community's attention to the wide distribution and availability of small-to-intermediate research telescopes and to foster collaborative observational projects. This effort is currently facilitated by a website database and bulletin board administered by SARA.

The diminishing availability of small (1-2m) telescopes at national facilities requires that new models for operating such facilities must be developed if they are to be preserved for the next generation of astronomers. Their users, typically faculty at small universities, must achieve an equitable voice in policy decisions affecting those facilities which support their research. In exchange, they must assume a larger role in the facilities' operation, management and funding. Consortia of small universities such as SARA are one model for meeting these goals.

We gratefully acknowledge support from the National Science Foundation (AST-9423922), the Research Corporation and the State of Florida Technological Research and Development Authority. Special thanks is extended to the National Optical Astronomy Observatories and Astronomical Consultants & Equipment, Inc.

Additional information can be found at the following websites:

 SARA Observatory:
 SARA REU Program:
 SARA NASTeC site:
 Florida Tech:
 East Tennessee State U.:
 University of Georgia:
 Valdosta State University:
 Florida International U.:

Unattended Automation as an Option for the Operation of Small Telescopes

Kent Honeycutt
Indiana University

Our experiences with six years of operation of a 0.41-m telescope for unattended CCD photometry of cataclysmic variables and quasars is described, as well as the newly installed 1.25-m telescope for stellar spectroscopy and fainter CCD imaging. For both telescopes all pertinent functions are automated for unattended automation, including open-up and close-down decisions, scheduling the observations, liquid nitrogen fills, focus, flat fields, finding the stars in the images, field identification, and updating the lightcurves. Typically a new data point appears on the lightcurve within 5-min of the completion of the exposure. On the 0.41-m telescope the effective magnitude range is 12 to 18.

Unattended automation has proven to quite effective in increasing the efficiency of observations and in reducing the cost of operations. However, the major motivating factor for our automation is the new kinds of science permitted by examining time scales that are otherwise unavailable under conventional scheduling policies at most observatories. Examples are presented from our long-term monitoring programs of CVs and blazars. Because of the strong science drivers we think that unattended automation should be a part of the mix of styles of operation of smaller US research telescopes, a viewpoint that we urge be kept in mind as the community continues to deliberate the future of NOAO's smaller telescopes.

IR on Small NOAO Telescopes: Science Programs and User Profiles

Ron Probst

I surveyed two years' scheduled programs for IR imaging on the KPNO 2.1-m telescope to determine the level of use of this capability, who uses it, and for what science. I suggest some implications for the future based on both science and technology.

The period surveyed is CY1995 and 1996. Effectively three IR cameras with differing capability were available at various times: IRIM, a 1-2.4 micron camera with 1.1" pixels, 4.5 arcmin FOV, and a very limited filter complement; COB, a 1-5 micron camera with 0.55" pixels, 2.3 armin FOV, and a very extensive spatial and spectral filtering capability; and DLIRIM, a modification of COB which gave 0.2" pixels. IRIM was available continuously, COB for one semester, DLIRIM for two semesters over this period. Normalized by availability, COB was most heavily used.

There were 37 scheduled proposals for 31 distinct scientific programs assigned a total of 181 nights. Since the least "popular" instrument, IRIM, was the only one available for one semester, this is a conservative estimator of demand. (COB was temporarily withdrawn for a detector upgrade.) Optical imaging and spectroscopy and IR spectroscopy are also done with this oversubscribed telescope; in this competitive environment, IR imaging science accounts for about 30% of available science time.

How big and how broad a community does this serve? Counting only listed investigators on the proposals, there are 89 PhD's and 7 graduate students, with 85 U.S. and 11 foreign affiliations. Institutionally, they come from 22 U.S. research institutions, 4 undergraduate colleges, 3 industrial R&D firms, and 9 foreign universities. Table 1 gives a listing, and notes when other IR imaging facilities were indicated to be available to the proposers. About 1/3 of the proposers or 1/2 of the proposals indicated such availability, typically small-field, high-resolution instrumentation on 4-m class telescopes totally unsuited to the proposed science. The few U.S. institutions with both strong IR instrumentation programs and small telescope access (e.g. Ohio State, Arizona, UCLA, Hawaii) are absent from Table 1. NOAO/KPNO is effectively a unique resource for widefield IR imaging for the rest of the U.S. community.

A review of the science programs indicates that, 10 years into the IR array revolution, IR imaging has taken its proper place as another observational tool to be used as appropriate. In summary, there were 21 galactic and 16 extragalactic programs. Most popular topics are star formation (7 proposals), structure and physics of nearby galaxies (7), late stages of stellar evolution (5), cosmological sources (4), statistics and flows of galaxies at moderate redshift (3). Many of these programs support or extend work with 4m and larger telescopes. Frequently near-IR imaging complements data obtained at other wavelengths, often greatly aiding the understanding of the physics. There were 18 explicit references to space experiments, including IRAS, ROSAT, ISO, HST, and UV platforms; and 13 references to large ground based facilities including the VLA, mm-wave dishes, and the Keck telescopes.

Could the science have been done on a smaller telescope, say 1-1.5m? I judged this to be feasible for only 20% of these programs. Only two proposals would be satisfied by the 2MASS database (which is targeted at different kinds of science). A similar review of IR imaging science done on the CTIO 1.5-m yields a science mix very similar to that described above, and indicates that on this smaller telescope the observations are frequently photon-hungry. The advent of numerous 8-m telescopes will increase the need for complementary IR imaging on faint targets with subarcsecond resolution.

This workshop is exploring alternatives for community access. For widefield IR imaging in the north, KPNO provides 100 nights/year PLUS instrument development time, allocated to a large number of individuals at many institutions--a management problem in itself. Judging from other presentations here, the competitive telescope size may be beyond the capability of many institutions or small consortia to acquire and support. The instrumentation is relatively complex, there are few vendors and no identifiable off-the-shelf products (unlike, say, simple CCD imagers), and the number of research groups with instrumentation expertise and appropriate telescope access is very small. Due to the way instrument projects hve been funded and carried out, even intra-institutional arrangements for access can be restrictive. These are resource availability problems which we must face.

What instrumental capability is needed to meet the science needs? Widefield IR imaging programs carried out at the national centers show a decreasing emphasis on continuum sources and exploratory imaging (broadband 1-2 microns with arcsec or larger pixels) and growing application to physical processes characterized by line emission which varies with high spatial frequency over extended regions. This demands 1% or better spectral resolution and subarcsecond pixel scale over a wide field. Sources of interest are getting fainter, typically K>15. There is increasing interest in the 3-4 micron range which will likely be further fueled by the 2MASS survey, Gemini capabilities, and long-wave space-based facilities. The historical tension between field of view and spatial resolution, due to the small size of IR arrays, is being relieved with the advent of 1-5 micron, 1024x1024 devices. A single such device, on a 2.5-m telescope with 0.5" pixels, will provide greater sensitivity at higher resolution over a larger field than ever before for "small" telescopes.

I have just exceeded the aperture limitation of this workshop! But for IR imaging science, "small" is getting bigger.

Table 1. Institutional users of widefield IR imaging at KPNO.
 Institution   # proposers*  other IR imaging access
 =< 2m  >2m
 CfA  18 X  
 NOAO  10   X 
 Vanderbilt  5     
 STScI  5     
 MIT  4    
 JPL  3    
 Maryland  3     
 North Carolina  3    
 Wisconsin  3    
 NASA, all centers  3    X
 Alabama  2    
 U. Seoul, S. Korea  2    
 Vassar  2    
 New Mexico State  2    X
 U. Cardiff, Wales  2    X
 Lawrence Livermore Lab  2  X  X
 DAO, Canada  2    X
 SUNY Stony Brook  2    
 Northwestern  2    
 Florida Inst. Tech  2    
 Texas  2    X
 Colorado  2    X
Carnegie Observatories  1    X
 Kapteyn, Netherlands  1    
 NRAO  1    
 IBM Watson Labs  1    
 U. Koln, Germany  1    X
 U. Crete, Greece  1    
 Carnegie Inst. Wash.  1    
 Indiana  1    
 IAUNAM, Mexico  1    X
 Hughes  1    
 Lowell Obs.  1  X  
 Valparaiso U.  1    
 U. Calgary, Canada  1    
 Drake U.  1    
 U. Bamberg, Germany  1    X
 Southwest Res. Inst.  1    
# proposers is not corrected for duplication of individuals. The CfA number derives from a team of several individuals carrying out a long term project with repeat proposals. The NOAO number represents five individual staff members.

The New 0.8-m Telescope at Vassar College

Debra Elmegreen
Dept. of Physics & Astronomy, Vassar College
Poughkeepsie, NY

Astronomy has a long tradition at Vassar, beginning with the college's opening in 1861. Maria Mitchell, America's first woman astronomer and one of Vassar's first professors, firmly believed that the best way to learn astronomy was to do astronomy; we adhere to that policy today. Her observatory, housed in a brick building in the middle of a tree-studded, brightly illuminated campus, no longer serves the needs of our astronomy department. We are building a new observatory at the edge of campus, and expect completion in spring '97. Known as the Class of 1951 Observatory after our primary donors, it will house a 32" f/6 telescope made by DFM, a 20" telescope made by Optomechanics, an 8" Alvan Clark refractor, and an 8" coelostat. We will have a 1024x1024 back-illuminated CCD and spectrographic capabilities. We expect to reach about 17th magnitude in V for 1% differential photometry at the new site, which is 3 magnitudes fainter than at the old observatory. The sky is about 18.5 mag, which is one mag fainter than at the old site, and the seeing is expected to be about 2.5" compared with the old 4.5". The new observatory will serve a variety of purposes, from public viewing at the Alvan Clark, to intro course observing and student training at the 20", to independent work, senior theses, and faculty research at the 32". Typically we have 10 senior majors per year, with about half in astronomy going on to graduate school. Long-term monitoring of variable objects, such as our study of SN 1993J in collaboration with our Keck consortium members (Colgate, Haverford, Middlebury, Swarthmore, Vassar, Wellesley, Wesleyan, and Williams) is ideal for small dedicated telescopes such as ours.

The Importance of Small Telescopes to Research and to Future Generations of Astronomers

John Huchra
Center for Astrophysics

There is a long and glorious history of important and fundamental research with small telescopes. Even in cosmology, small telescopes have been key in recent work on the Hubble constant and on mapping large scale structure. The IRTF relation was ``discovered'' on the KPNO 0.9-m and calibrated on the mighty KPNO 0.1-m; large surveys such as the CfA Redshift Survey were done on small telescopes (the FLWO 1.5-m) and it is not possible to assess the great contribution to astronomy made by the Palomar Sky Survey, which was done on a 1.2-m telescope. Small telescopes are absolutely necessary for key projects, trying out novel ideas, testing instrumentation, teaching and just the general practice of astronomy.

However, there is no doubt that ``times are a changing.'' There are numerous issues that need to be addressed in assessing the need for small telescopes in general and the need for small telescopes at the National Observatories. A short list includes the need for access, amateur astronomers, Federal versus state versus private funding, the synergy of small telescopes feeding large telescopes, and last but not least, budgets --- operations, site costs, moderan instrumentation, peripherals.

The good news is that, despite all this, many new small telescopes are being built. And, amateurs now run 1-m class telescopes. The bad news is that with fixed budgets, the National Observatories can no longer *easily* provide access to every type of telescope and instrument. There is no right of access to facilities of every kind for every scientist; the NSF exists to enable science in general. A more positive way of thinking about our current problem at NOIRLab, is that it's really an opportunity. I once said ``the 4-m is the 60-inch of the future.'' The astronomical commnunity *is* getting Gemini plus new access to 4-m telescopes like WIYN and SOAR, so in reality our national facilities are just getting bigger by a factor of two! We're redefining small.

If the community wants to push for more or continued support for small telescopes, the issues to address *must* be science based. We must take the high road. Individual key projects like the Sloan DSS, training and education, the development of special purpose consortia (not Federally funded) are all good arguments. It is absolutely clear that small telescopes are needed and indeed are a National treasure. New small telescopes are being built right now, like the 2MASS telescopes, justified by important scientific programs best done on small telescopes. It is also clear that the community will need some creativity in finding funding sources and will likely need to find new ways of operating them.