Digital Art and Space Blog
Reflections on Art, Computer Graphics, Photography, Space and Astronomy

Last night was the first session of the “Astrophotography and Large Telescopes Workshop” class that I am taking at the Adler Planetarium. The class is being taught by astronomer Dr. Mark Hammergren and consists of three three hour sessions. The course description for the class reads as follows:

“Use research-caliber telescopes and specialized equipment to photograph your favorite deep-sky objects! Get hands-on access to the Adler’s 20-inch reflector in the Doane Observatory and remote control over the 150-inch reflector at the Apache Point Observatory in New Mexico. Learn to find and photograph faint asteroids, nebulae, galaxies, supermassive black holes and more.”

In last night’s class we discussed a variety of topics including:

• competition for observing time at the major observatories
• planning observing sessions at the major observatories
• characteristics of CCDs
• evaluating CCD performance
• quantifying CCD irregularities via bias frames, dark frames, etc.
• instrumentation (visual, IR, spectroscopy, etc.)
• discussion of the telescopes that we will be using
• elementary information on RGB and the creation of color images in Photoshop using the Hubble Space Telescope Eagle Nebula image as the example.

Following the lecture portion of the class we had the opportunity to go outside and see the Doane telescope in action. The Adler’s Doane Observatory is home to a 500-pound Cassegrain reflector with a 20-inch (0.5 meter) diameter mirror. The telescope uses a fork-style equatorial mount and its 0.5 meter diameter aperture and 4 meter focal length gives it a focal ratio of f/8 at prime focus. The mirror was created using the spin-cast technique. For instrumentation, there is a Finger Lakes Instrumentation 1024 x 1024 pixel CCD that has a 21 arcminute field of view.

According to Dr. Hammergren, in choosing targets for our Doane observing session we should focus on objects that are at least 30 degrees above the horizon; in the eastern part of the sky; and that are at least 15th magnitude for point sources or 13th magnitude for extended objects. Note that the Doane is open to the public during the planetarium’s Far Out Friday events. and for special observing events. Because this was a “Far Out Friday”, we had to be content to wait our turn to get a look through the telescope. The target this particular evening was our own Moon.

The picture at the top of this post was taken as I waited inside the dome for my turn to look through the telescope. Afterwards I headed outside to take some exterior shots of the observatory. One set that I was particularly pleased with was used to create the picture seen below. I dubbed it “Ghosts of Doane Observatory” because of the specter like appearance of the figures.

The second class in the series will be devoted to using the Adler’s Doane Observatory for making our telescopic observations, For this class, we will have exclusive use of the observatory. I can only hope that we will have a clear night for our class.

For the third and final class, we will get to use the Astrophysical Research Consortium 3.5-meter Telescope at Apache Point Observatory. In terms of instrumentation, we will be using either the SPICAM (Seaver Prototype Imaging camera) CCD camera or the DIS (Dual Imaging Spectrograph). SPIcam is a SITe 2048×2049 pixel CCD with a 4.78 x 4.78 arcminute field of view with 0.14 arcsecs per pixel. For details see Quick Guide to using Spicam. The Dual Imaging Spectrograph has a 4 x 6 arcminute field of view. Unfortunately I have no additional information about this instrument.

I am looking forward to the remainder of the class and with working on the images that we acquire doing our observing runs.

Ad Astra, Jim

Yesterday I received an email that contained some pictures of the relative sizes of the planets and some stars. One of the more impressive pictures was one that showed the relative sizes of Antares and Betelgeuse, two red giant stars, as compared to our own Sun. In the discussion of these images one person posed the question “so … How significant should we really be feeling, right about now?”
which set me to thinking.

I have seen statements to the effect that there are as many galaxies in the Universe as there are stars in our own Milky Way galaxy. I have seen estimates for the number of stars in the Milky Way that range from 100 billion up to 400 billion. For our purposes let’s suppose that the number is closer to 200 billion
and that all galaxies average the same number of stars, realizing that any average of this type could be off by literally astronomical proportions.

So we are talking about 200 billion galaxies that average 200 billion stars each. Simple multiplication reveals that there are on the order of 4 x 10²² stars in the Universe. In more traditional form, that is 40,000,000,000,000,000,000,000 stars.

Now that’s a lot of stars but consider this: I have seen estimates that a person who weighs 70 kilograms has about 7 x 10²⁷ atoms in their body. Again that’s 7,000,000,000,000,000,000,000,000,000 atoms, a whopping big number. That means that there are more atoms in my body than there are stars in the entire universe.

You can get a ballpark on the number of atoms in your body by first converting your weight from pounds into kilograms with 1 pound being equal to 0.4536 kilograms. Then all you have to do is plug your weight in kilograms into the following equation:

Atoms = (your weight in kilograms / 70) x (7 x 10²⁷)

And as a parting shot, realize that the latest estimates are that the atoms that make up all our bodies and all the stars and all the dust and gas of the universe represent only about four percent of the “stuff” that makes up the Universe. Kind of gives you the feeling of doing a Linda Blair head spin (couldn’t resist that since this is Halloween).

Ad Astra, Jim

This is easily the most impressive picture that I have ever seen of Saturn. The picture of Saturn shown above is one of two versions of this Cassini panorama of Saturn.

With respect to how this picture was made, quoting from the CICLOPS (Cassini Imaging Central Laboratory for Operations) web site:
“This marvelous panoramic view was created by combining a total of 165 images taken by the Cassini wide-angle camera over nearly three hours on Sept. 15, 2006. The full mosaic consists of three rows of nine wide-angle camera footprints; only a portion of the full mosaic is shown here. Color in the view was created by digitally compositing ultraviolet, infrared and clear filter images and was then adjusted to resemble natural color.”

I definitely encourage you to read the article In Saturn’s Shadow at the CICLOPS site and download the pictures of Saturn there. Another article about this unique panorama can be read at JPL Cassini-Huygens Mission to Saturn and Titan web site.

Looking back at the space and astronomical art that was being creating prior to the space age only goes to show that nature is more beautiful and varied than imagined by the mind of man.
Ad Astra, Jim