Leander McCormick Observatory
26-inch Instrumentation: Student Spectrograph
The 26-inch has been equipped with an Opto-Mechanics Model
10-C spectrograph with a Santa Barbara Instruments ST-8 CCD as a
detector. Both instruments were designed for use with Meade
Schmidt-Cassegrain telescopes, but we have adapted them for use with
the LMO 26-inch refractor. Information on the ST-8 CCD is
available here.
The spectrograph is professional-grade with a CCD detector. With this
device, students can measure, among other things, the compositions and
Doppler motions of celestial objects. "It is very rare for
undergraduate students to have access to a telescope as large as the
26-inch, and even more rare to have access to one equipped
with such modern instrumentation," according to Steven Majewski,
who teaches both graduate and undergraduate labs. "This unique new
facility greatly enhances our ability to teach astrophysics to
undergraduate and graduate students and is a great complement to our
already strong pedagogical emphasis at UVa."
Sample Spectra
These are just a few examples of the types of observations that can be made with our new student spectrograph. We will be incorporating its use more and more in ASTR 130 (lab for non-majors), ASTR 313 (lab for majors), and ASTR 511 (lab for graduate students) in the coming semesters.
This is a spectrum taken with the LMO 26-inch refractor and the
Opto-mechanics spectrograph. The spectrum is of EN Aqr, an M3 giant
star in our galaxy. Note that the overall shape of the spectrum is like
that of a black body, but in addition there are a large number of deep,
broad absorption lines.
This spectrum is of M27, the Dumbbell Nebula, a planetary nebula in our
galaxy. Planetary nebulae glow brightly in the light of oxygen ions,
and the two large lines you see are the 4959/5007 Å doublet of
twice ionized oxygen.
