On the night/morning of May 12/13th, 1998, I participated in Kitt Peak National Observatory's Advanced Amateur Observing Program. I spent an entire night working with a staff astronomer, a Meade 16" Schmidt-Cassegrain telescope, and SBIG (Santa Barbara Instrument Group) ST7 CCD (Charge-Coupled Device) camera. The wind was howling and the seeing (clarity/stability of the atmosphere) was awful, making precise focus difficult and variable. The telescope was not mounted to a pier isolated from the building, so it shook with the building in the wind. To make conditions even worse, there was the tremendous light of a full moon drowning out all the interesting stuff we wanted to look at.
Exposures were necessarily very short because of the wind's tendency to make the telescope lose its guide stars. This means that the images do not contain nearly as much information/clarity as we would like. The longest exposures were only about five minutes. Nevertheless, it is positively amazing what a CCD can do. No conventional camera/film could have recorded anything on that night.
The Facility
This is the dome housing the telescope with which I worked.
It is attached to the Visitor Center on Kitt Peak. The telescope
was being prepared for a public viewing prior to my work when the photo
on the right was taken, so it is seen here with a conventional eyepiece
rather than the CCD attached.
b Cygni
This is the binary star b-Cygni
or Albireo. It is along the Milky Way path and I originally envisioned
a really exciting (and larger) shot with lots of background stars.
They don't appear, however because the subject is so bright. We did
manage to capture the dramatic color difference between the two stars.
To get a color image, exposures were made through each of three colored
filters: 0.11 seconds in red, 0.13 seconds in green, and 0.33 seconds
in blue. The different exposure times compensate for the varying
sensitivity of the detector at each respective wavelength of light.
b Lyrae
This is a multiple star system, b Lyrae.
The exposure was 5 seconds. On a better night, these images would
appear much smaller.
Planetary Nebula M57
This is the famous "Ring Nebula" M57 in Lyra.
It is an expanding shell of gas that was once the atmosphere of a star.
The faint dot in the middle is a white dwarf star. It is the remnant
of the (former) star's core. It is about the size of the earth, but
has a mass of about half the sun. A thimbleful of its material would
weigh about a ton on Earth. This is a lovely object in color.
We were unable to make sufficiently long exposures to get a decent shot
in color. Exposure time was 5 minutes.
Globular Cluster M4 in Scorpio
This is one of a glut of globular clusters we imaged.
These are bright and spectacular... easy to get decent images of in short
exposures (this one was just five minutes long). This shot does not
do the cluster justice. The fuzzy stuff in the middle is the underexposed
image of thousands of stars. The cluster contains nearly half a million
stars.
Globular Cluster M3 in Canes Venatici
Another five minute exposure. This shot looks
especially fuzzy because of the bad seeing. Globulars are typically
more exciting to look at through the eyepiece than in their photographs
(not the case for most deep-sky objects).
Globular Cluster M22 in Sagittarius
Like the two preceding clusters, this one would look
better with a longer exposure in black & white. (It has lots
more stars than are evident here). I wanted to try a color picture
of a globular just to confirm my suspicion that its stars would have a
noticeable orange appearance (because these clusters are thought to be
much older than any energetic blue-white main sequence star could be).
Exposure times were 5, 6, and 10 minutes in red, green and blue light,
respectively.
Spiral Galaxy M83 in Hydra
I had high hopes of imaging several galaxies (and
could have expected a much better image of this one on a still night).
This is the "Southern Pinwheel" galaxy in Hydra. Its declination
is -30 degrees, so it would be virtually impossible to get a good look
at from up here in da great white nort den.
Lunar Highlands
All right, if you can't beat it then target it.
The background light of the full moon was substantially responsible for
our inability to see fainter features of clusters and galaxies. So
here's a look at the extreme southeastern limb of the full moon.
Exposure time 0.11 second.
Mare Crisium
This is the "Sea of Crises" on the moon's northeastern
limb. Another 0.11 second exposure.
To give you an idea of just how debilitating the
conditions were on the night I was there, here's a link to a site
full of images far superior to those that I have obtained with the
very same equipment. There are numerous pages, so you can stop when
ever you get tired of all the splendor. Thanks for dropping in on
this page. You are invited to email me with questions, comments,
additions or corrections.
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