Milt Hull, our energetic president, took the microphone at the June meeting to talk about telescopes and some software that controls them. Planned speaker Chris Cowen from Star Safari did not show up, but Milt, ever at the ready, took over since he has "always been kind of involved in looking at the stars," he explained. He particularly likes to go camping, lie under the night sky for hours, and watch for shooting stars, try to spot satellites as they pass, and note the occasional airplane as it passes. Out away from the lights of the cities, he can work on identifying the constellations "and all that stuff, and it is pretty interesting, " he says.
He started out when he was a very small kid when he could not afford a really good telescope. His dad bought him a little refractor, about 11/2 to 2 inches, which did not show very much. About ten years ago he bought a 41/2-inch scope from a friend. "That was a pretty good scope for a long time," he said, and he "could see the craters of the moon and all that stuff," including some of the moons of Jupiter and the rings of Saturn. But, like all things technological, good wasn't good enough, and about a year ago he had enough money, about $3100, as it turns out, to get the new scope. Since then, he has added more and more features and now has "about ten grand into it," he reports. It seems that several scopes have come down in price since then, as is the case with many things technological these days. A number of options are available for those who want to acquire a scope and its peripherals, Milt reports. Milt has joined the Sacramento Valley Astronomers Association (www.skywatchers.org), a fun group to join, he said.
After his preliminary remarks, Milt had on hand some software programs to demonstrate and a couple of copies to give away later in the evening, thanks to Chris Cowen.
Software and Telescopes
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| Milt discusses what the telescope could see if it was outside. |
| Click the thumbnail for full image. (53K) |
The program that Milt demonstrated is "The Sky," (level 4, version 5, top of the line, about $200.00) from Celestron, a maker of telescopes of various kinds and some software programs that control them (www.celestron.com). It is possible to run the software without connecting to the scope. It contains a computerized map of the skies with a database of 10,000 objects; it will also print charts of the sky. However, in the field, the most important thing to do is to tell The Sky where you are: longitude and latitude, elevation (about 50 feet at Sacramento), the time zone (minus 8 hours from GMT: Greenwich Mean Time). At Blue Canyon, where the club meets, elevation is 5200 feet and the longitude and latitude are a bit different as well.
Second, the software needs to know what kind of telescope is being used. Many telescopes have numerous controls that allow them to follow stars automatically, for example; and the more features the scope has, the less the software has to do to control the scope. Filters are also something to play with: you can filter out the stars and leave only the galaxies, or set them to show only the planets or the Messier Objects (Milt explained that Charles Messier found the 110 brightest objects in the sky in the 16th and 17th centuries, labeled them; and they are now known as the Messier Objects).
Much of Milt's demonstration was showing how the program works and moving parts of the program and the telescope to show their possibilities, a clearly visual demonstration that can't be reproduced well here. However, Milt explained that the amount of light and darkness have a lot to do with the various settings of both; he had set the brightness control at a rather high level so that it would be visible in the auditorium. He was able to show how the Northern sky would look late at night, and how the stars move around Polaris, the North Star, which itself does not move. Milt demonstrated how the program can present the sky in different directions: South or West, for example, as it also emulates little mountains.
He next wanted to show the sun. Clicking on the sun caused the program to bring up a lot of information on the sun: when it rises and sets on a given date, when it transits, size, declination, altitude: all the information that astronomers look for about the sun. You need to be very careful scoping the sun without using special sun filters. Without the filters, you could blind yourself instantly and damage the scope; it would get hot enough to melt the mirror. The Sky will also give similar information about other objects in the sky-Venus, for example-when it rises and sets, its size in relation to the sun, and numerous other details. The information that Milt brought up relates to our position in Sacramento, but you can get the same information related to places like Mexico City or Australia. In each case, the program has to be set according to longitude and latitude; it automatically compensates for different speeds of the turning Earth according to latitudes. For example, at the equator, the Earth turns at 1038 miles per hour; at Sacramento the speed is less due to the reduced circumference. The program controls the telescope according to these parameters.
Milt then focused on Orion and its star Betelgeuse and obtained information appropriate to it. To see the entire nebula of Orion, one of the most popular since it is so big, he says that he has to use an eyepiece with a wider field. He showed a number of different pictures, and indicated that the Sacramento Valley Astronomers Association "has a ton of links to get pictures." [How many links to the ton? -Ed.] The "field of view indicators" show the different views you get depending on the type of eyepiece or camera you use.
The program has a few multimedia features that present pictures of many of the objects in the sky. The version that Milt demonstrated comes with two CDs, with images of the many Messier Objects and pictures from the Hubble space telescope. These can be enlarged and printed, as well.
In addition, it has a number of other features: a planet report that gives general information about where you are and general information about every planet in the solar system; a Moon-faced calendar that tells you the best time to take your telescope out; and when there is no Moon so that you can see nebulae in the deep sky; there is an eclipse finder that tells when one will occur, among other fantastic things, including loading many of the data on to a CE device.
Milt is impressed with this program; he said that it "is phenomenal." It used to be shareware in the '80s and has come a long way, which is why it is so expensive now. The version he gave away, though, is level 1, which does not control most scopes and has only about 64,000 objects in its database, still a good many more than you can ever find, he says. Version 5, however, has 281,000 objects.
Milt then talked about what we see when we look through the telescope. Naturally, we see things in black and white, not in the colors that we can see on the screen of the computer, but there are color filters that enhance the images, and you can then combine pictures taken with different filters to get pictures of Orion, say, in full color. He demonstrated a CCD digital camera (SBIG, Santa Barbara Instruments) along with a filter wheel that changes automatically as it shifts from one filter to the next to take pictures at different exposures. This system uses a program called Maximum DL ($350) that controls everything: camera, filter wheel, telescope; there is a water line to the camera to keep it cool, since with exposures as long as 12 minutes it can get quite hot; it also includes a dew shield to keep the dew off the lens on cold nights and mornings.
An interesting anecdote: A man who lives in Colorado has his telescope somewhere in New Mexico. He runs the scope with his software linked through the Internet and can control everything. It's also possible to buy time on some of the big research scopes around the globe.
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| Milt and his telescope. |
| Click the thumbnail for full image. (51K) |
For the astronomer, Milt points out, the first thing, obviously, is to get a telescope; however, the software can be run without one, which is what he did for his demonstration. To look at the stars, you need to go away from Sacramento, a place "lousy for looking at the stars because of the light pollution." When you get to where you want to go, you must not run headlights, your flashlights must be red, and the computer screen can't be too bright; it has a night vision mode.
At the end of the meeting, Milt gave away two copies of The Sky, level 1, provided by Chris Cowen (Chico 800-870-3616) of Star Safari for which Milt was grateful as he did not want to give away his telescope.
