The Southeastern Association for Research in Astronomy (SARA) Consortium

Through the SARA Consortium, Ball State University has access to professional observatories that can observe the entire celestial sphere, and have nearly 24 hour access to northern hemisphere objects.  Access to these facilities grants Ball State University a total of 55-60 nights per year devoted to the scientific pursuits of the Faculty and students of the department.  The distribution of nights/year is as follows.

That amounts to approximately a night a week for the entire year. Institution observing nights for each observatory are distributed individually through out the year unless requested otherwise. As a consequence travel to the telescope becomes difficult for on-site access. Typical access is via remote desktop from the host institution. Remote access is a cost effective way to allow frequent access to the telescope at a minimal cost of time and effort. Even though the student misses the in-dome experience of controlling the telescope, the benefits gained from the frequency of nights available for science image acquisition with minimal interruption to normal academic activities–a student can observe at any of the SARA observatories for a night and attend classes the following day–is making remote access the standard at professional observatories. To give our students the in-dome observing experience we use the BSUO. On-site access is permitted but is rarely used for this reason.

Further details regarding each observatory can be found below.  These nights are frequently devoted to the research activities of both the undergraduate and graduate students of the Department of Physics & Astronomy.  Each astronomy student works closely with a faculty member of the department and receives a uniquely tailored education to learning the necessary skills to not only prepare for an observing run but also to control the telescopes.  Direct access to professional-quality observatories and a unique educational experience gives our students invaluable observing experience not frequently seen in other programs.

SARA-KP

The first telescope maintained by the SARA Consortium and located at the Kitt Peak National Observatory about an hour westward by car from Tucson, AZ.  The telescope began observations with the SARA consortium in 1990.  Initially observations were only performed by onsite observers, but regular and reliable remote internet control of the observatory began in 1995. The telescope is located atop Kitt Peak at +31º 59′ 26.1″ North latitude and 111º 35′ 58.0″ West longitude at an altitude of 2073 m.  SARA-KP has a focal length of 6858 mm and a clear aperture of 0.914-m results in an effective focal ratio of f/7.5.  The plate scale at the focal plane is 30.1 “/mm.

Several camera can be attached to SARA-KP, and characteristics are summarized in the section immediately following the observatory sections.  The main imaging instrument is the Astronomical Research Camera, Inc. (ARC) camera that contains an E2V CCD42-40 chip with a 2048 x 2048 array of 13.5 µm pixels.  The physical size of the chip is 27.6 x 27.6 mm.  The chip is thermoelectrically cooled to a temperature of -110 C. At the focal plane each pixel is 0.406 “/pixel which results in a field of view of 13.9′ x 13.9′.

On-site limiting magnitudes with a Signal-to-Noise ratio (S/N) = 10 for a 10 minute exposure are to 20.8 in B, 20.1 in V, and 20.1 in R.  An observer can expect typical seeing on an average night around 2”.

The image shows the SARA-KP Observatory (sliver dome) in the foreground atop Kitt Peak. The telescope in the background is the Bok telescope operated solely by the University of Arizona’s Steward Observatory. Normal operations cover approximately eleven months of the year with a mountain-wide shutdown of Kitt-Peak National observatory for the month of August to avoid the Arizona “Monsoon” Season.

SARA-CT

The telescope has a clear aperture of 0.61-m and a focal length of 8230 mm which results in an effective focal ratio of f/13.5.  This results in a plate scale of 25.1 “/mm at the focal plane.  The main imaging instrument is another ARC E2V CCD42-40 chip which is a 2048 x 2048 array of 13.5 µm pixels.  This results in a physical size of 27.6 x 27.6 mm.  At the telescope focal plane this yields a 0.338 “/pixel and a field of view of 11.5′ x 11.5′.

Despite its small size, on-site limiting magnitudes with a Signal-to-Noise ratio (S/N) = 10 for a 10 minute exposure are remarkably good and are down to 20.4 in B, 19.5 in V, and 19.4 in R.  This is a testament to the quality of the CTIO site.  An observer can expect typical seeing for an average night to be around 1.5”.

The image shows the SARA-CT Observatory with the main CTIO observing peak in the background. The SARA-CT telescope grants BSU faculty and students access to the southern hemisphere of the celestial sphere and compliments the aforementioned SARA-KP observatory by providing access to portions of the celestial sphere not visible to SARA-KP and SARA-RM. With this telescope BSU faculty and students can include a portion of the celestial sphere that historically has seen relatively little scientific exploration. The large telescope (silver dome) in the background is the Blanco 4-m telescope operated by the National Optical Astronomy Observatory (NOAO).

SARA-RM

The telescope has a clear aperture of 1.0-m and an effective focal ratio of f/8.  The primary imaging camera is an Andor Ikon-L CCD camera with a 2048 x 2048 array of 13.5 µm pixels. With a telescope focal length of 8000 mm, this produces a plate scale at the focal plane of the telescope of 25.8 “/mm or 0.335 “/pixel. The physical size of the chip is 27.6 x 27.6 mm, and produces a field width of 11.6′ x 11.6′. The chip is thermoelectrically cooled to a temperature of -50 C. Bessel and SDSS standard filters in addition to a narrow-band Hα filter are available to observers for imaging. A currently free instrument port exists allows for guest observers to attach an instrument for on-site observers.

On site limiting magnitudes with a Signal-to-Noise ratio (S/N) = 10 for a 10 minute exposure are to 21.4 in B, 21.6 in V, and 21.1 in R.  It is not uncommon for an observer at SARA-RM to experience seeing of >1”.

Image shows the SARA-RM telescope with the dome open during the daytime.  People shown in image are SARA board members in attendance at the rededication of the telescope in October 2015.  The 1-m Jacobus Kapteyn telescope is apparent in the open dome slit.  The telescope in the background is the Issac Newton Telescope.

CCD Cameras of the SARA Consortium

The Ball State University Observatory (BSUO)

16-inch (0.4-m) Schmidt-Cassegrain telescope

Telescope pointing is confirmed by determining astrometric solutions for each by the PinPoint Astrometric Engine by DC3 Dreams.  All images are saved in the Flexible Image Transport System (FITS).  For more information please see the Library of Congress page.  Telescope position, image acquisition date and time, read noise, gain, exposure length, and astrometric metric solutions for each image are stored in the headers of each fits file.

The telescope has a focal length of 4064 mm which results in a focal ratio of f/10.  The resulting plate scale is 50.75 “/mm.  The telescope can also be setup in an f/6 configuration which results in a focal length of 2438 mm and a plate scale of 84.59 “/mm.  The telescope mount is a fork mount which has the advantage that pier flips as an object passes through the meridian are not necessary.  This is often at the expense of telescope stability,  but we have not confirmed any oscillations in the telescope fork mount.

The telescope can use one of four Charged Coupled Device (CCD) cameras to acquire science images. These cameras are are listed in a table beneath the 20-inch telescope on this page.

For instructional purposes, we can force manual operation of the telescope.  This allows students the opportunity to gain invaluable experience similar to the experience gained by observing at a research-grade telescope at a professional observatory.

20-inch (0.5-m) Parallax Ritchey-Chrétien telescope

The 20-inch telescope has a 4114 mm effective focal length, and results in an effective focal ratio of f/8.1.  The telescope mount is a German equatorial mount (GEM).  The CCD camera most frequently used for imaging is a Finger Lakes Instrumentation (FLI) PL16801 camera.  The Proline 16801 contains a front illuminated Kodak KAF-16801 4k x 4k chip with 9 µm square pixels. The PL16801 camera is one of the few FLI cameras that lacks the anti-blooming feature that can compromise chip linearity. The physical dimensions of the chip is 36.8 mm x 36.8 mm.  At the f/8.1 telescope focal plane this results in a plate scale of 50.15 “/mm or 0.45 “/pixel, and a remarkably wide field size of 30.8′ x 30.8′.

Most science observations made with the 20-inch telescope are automated by the DC-3 Dreams ACP Observatory Control Software.  Evening and morning science calibration images and science images taken throughout each night are automated by an observer provided script. To generate these scripts requires careful planning and knowledge of the necessary data to be acquired each night. The generation of these scripts gives our students and observers invaluable experience in learning observing run preparation.  Telescope pointing and image plate solutions are determined with the PinPoint Astrometric Engine, and are automatically stored along with gain, read noise, and date and time of exposure in each image headers.

The telescope can use one of four Charged Coupled Devices (CCDs) to acquire science images. These cameras are are listed in a table immediately following this section.

For instructional purposes, we can force manual operation of the telescope.  This allows students the opportunity to gain invaluable experience similar to the experience gained by observing at a research-grade telescope at a professional observatory.

CCD Cameras for the telescopes of the BSUO

1. SBIG ST-8
2. SBIG ST-10
3. SBIG STL-6303e
4. Finger Lakes Instruments (FLI) PL16801

Typically the FLI camera finds its home on the 20-inch, and the STL-6303e camera on the 16-inch.  The CCD characteristics for both the 16-inch and 20-inch telescopes in the BSUO with each focal length configuration is given below in the following table.