February 2005 Club Meeting Report

The meeting started promptly at 7pm. 18 people were in attendance. It was noted that the "pre-meeting" gathering at the Parker Food Court had 6 people in attendance, and was a nice way to start the evening. We'll continue to do this as a regular tradition of the club. The only first-time attendee was Greg Wirth of Keck Observatory. The meeting was full of familiar faces.

During the Gear Talk Show and Tell part of the meeting, a pair of red tinted "AstroGoggles" was shared. These can be used to create and preserve night vision. A person can wear these prior to observing to build up their dark adaptation. Also, these can be donned when needing to go indoors for a moment. They are available through Orion for $19.95. More information at Orion Telescopes. Craig Combes shared a 2" lightweight focuser by KineOptics. The focuser is a helical type and is designed for Dobsonian telescopes. More information can be found at: kineoptics. A green laser pointer was demonstrated. The consensus is that green laser pointers are presently about $100 and prices may continue to fall. Finally, Doug Summers demonstrated the planetarium software "Where the Stars Are". This simple, powerful program is able to do all the main tasks that most planetarium program is asked to do. It's deceptively simple & yet very powerful. And, the price is right...Free! Doug will provide a copy to anyone who volunteers to help the club. Suggested items would be giving a short talk, helping organize a star party, etc. Doug has verified there is no current copyright on the program. Both Orion Telescopes and Software Bisque have cleared distribution of the program for educational purposes. Given that the program is the pregenitor of "TheSky" (TM), if folks like this program, they will love newer Software Bisque offerings....check them out!

Scott Hartman then took to the stage to introduce a few featured web sites for the month. The first site is a seeing predictor for Hawaii. This can be used to estimate what the seeing of the night sky will be. It is available on the Mauna Kea Weather Center site, "Mauna Kea Seeing". The second site Scott introduced was are the Astro League Observing clubs. Go to www.astroleague.org and click on "League Info" at the top center of the page. From there, select "Observing Clubs". Or, to go there directly --> "Astro League". An individual can join the Astronomical League for $30/year, or clubs can join as a whole giving the members individual access. (note: WHAC is not an AL member) Regardless if you are an AL member or not, they have several observing clubs that are free to use as excellent observing aids. As a specific example, Scott opened the Messier Club. It has a write up about Charles Messier and the Messier list. Near the bottom of the page you can click on "The Messier List" and it gives you a list of the object sorted by season. The Lunar Club is similar, but for lunar objects. The Moon is an excellent object for beginners to start with. The Moon is easy to find and get started with. Observing the Moon requires the same observing skills as are required for all other night sky objects. It was mentioned that on the WHAC web site under Astronomy Links is a link that creates a calendar of the phases of the Moon.

Laura Kraft then presented "The Sky This Month" Laura used Starry Night Backyard, an outstanding planetarium program. Starry Night planetarium programs are available through "Starry Night". (Note: it appears that Starry Night Backyard which Laura used is no longer offered by Starry Night. They presently offer Starry Night Enthusiast 5.0 which is close to Backyard in terms of capability and features. SNE is available for $80. They also offer Starry Night Pro for $150. Pro appears to be the top of their software line. On their web site Starry Night also sells upgrade packages from their older versions, such as Backyard, to the latest releases. And remember, Doug can set you up with a nice, FREE planetarium program for helping with the club!). Laura showed that the Moon is very near the Pleiades on February 15. Saturn will be prominent all month. Jupiter is prominent in the morning sky, rising at ~10pm in mid-February. The Moon and Jupiter pass within 2-degrees on February 27. Comet Machholz is approaching the north star and growing steadily fainter. Venus remains a remarkable "Morning Star". Throughout the discussion Laura gave a planetarium view of the prominent constellations.

Doug Summers then facilitated several pieces of club business.

Mark your calendars -- The first-ever WHAC star party is firmly set for March 12, 2005 at the "Waikoloa Obelisk" parking lot, which is at the junction of Waikoloa Road and Mamalahoa Highway. Contact a club officer if you are unclear where this is. We will have a "hotdog cookout" social well prior to sunset. Club funds will be used to pay for hot dogs and chips (BYO other stuff). At the next club meeting we will discuss the details of the star party/social. For now, Doug asks for people to volunteer in helping clean up the site prior to March 12. Again, details next month.

We still have some fantastic Canada-France-Hawaii Telescope calendars for sale. These were given to the club by CFHT to support our efforts. You can support the club by purchasing one or more. See Doug to buy one. For details about the calendar go to: "CFHT Calendar"

We also wish to sell the remaining copies of various Symantec products that were given to the club. These are 2005 versions of Norton Antivirus, System Works, and Internet Security. The price is "half off the lowest internet price you can find". Both the calendars & Symantec products are "perishable" (2005); See Doug if you are interested. Thanks to those who have supported the club fundraising by purchasing one of these products!

Laura announced that there are several interesting lectures upcoming at Keck Observatory. On February 17 at 7pm Dr. Jim Fanson will talk on the Galaxy Evolution Explorer, for which he was the project manager. On March 11 at 7pm, Dr. Alex Filippenko will give a talk. The topic has yet to be announced. Dr. Filippenko is a regular observer at Keck and one of the world's leading astronomers.

For more information about the Keck Lecture Series, see "Keck Lecture Series"

The next WHAC meeting will be at the Canada-France-Hawaii telescope headquarters in Waimea. Reminder that anyone wanting to gather for a pre-meeting snack/dinner, rendezvous in the Parker Ranch Food Court at 6pm. We'll gather at the tables in front of the big fireplace.

Doug Summers was the featured speaker of the night. He spoke about the construction of his DGT telescope - Doug's Giant Telescope. It is a 22" f/3.745 and required one full year of effort from the start of construction to first-light. First light occurred on June 8, 2003.

Doug built DGT due to "Aperture Fever!" He wanted a telescope as large as practical within four main objectives:

1. Low eyepiece height (i.e., no ladder)
2. Top of the line optics
3. Manageable by one person
4. Transportable

Several factors were considered including aperture, focuser height versus aperture and focal length, manufacturing/testing of fast optics of large size, the weight of telescopes versus aperture, etc.. Doug's bottom line conclusion is that the largest telescope manageable for one person is 22". No vendor sells fast telescopes of 22" aperture, so DGT became a custom telescope project. The RFPs for optics went out on June 9, 2002.

For those considering building their own telescope, or even to just understand telescopes better, he recommends two books:

Telescope Building by Jean Texeraux
The Dobsonian Telescope by Kriege/Berry (see the Willam Bell link on our links page)

Ultra light design concepts were considered, such as flex rocker telescopes, but ultimately flexure, holding collimation, and the unprotected state of the mirror in these styles of telescopes concerned him such that he opted for a more conventional design. Doug decided to build a telescope heavily influenced by the Obsession Telescopes design. The final specifications of the telescope are 22" f/3.74 with a 6'6" eyepiece height at zenith. It has 6372x the light gathering power of the unaided human eye. The DGT has a telescope weight of 185#, uses a 4.5" minor-axis diagonal mirror, and produces a 5-micron Airy disk. A mirror cell design program called PLOP was used to design an 18-point cell that introduces a miniscule 1/65 wave of mirror cell error. PLOP is available at: Plop Mirror Cells. Many design considerations were presented, such as interferometry testing of the optics and Foucault testing. Looking back on creating the DGT, several observations/experiences are of note:

- Distant vendors are harder to work with. Being in Hawaii, all vendors are distant
- Hardware stores on the Big Island -- not enough of them
- Once metal and/or wood are removed, they are hard to replace
- Build a small telescope first before taking on a monster telescope project
- When building a big, fast telescope get the best focuser possible
- It is hard to stop building and fussing with the telescope and start using it
- The telescope performs very nicely on-sky, which was the goal

The formal part of the talk and meeting ended at ~8:45pm. We then took a closer look at the DGT (it was at the meeting). Then, it was relocated outside to give everyone a view of the Orion Nebula. Unfortunately, we only got a relatively poor view of the nebula...lots of water vapor in the air above Waimea. We'll repeat that view during the star party in March for a better look!.

That's it folks....see you next month at the pre-meeting food court gathering, and then at the meeting (remember CFHT this time!). And, start thinking about our Spring Star Party....it's Messier Marathon time too!