Further report on a Public Night at Lick

by Jay Freeman

It is always interesting figuring out what to show the public, and how to go about it. They come in all ages, sizes, shapes, and levels of physical condition. Some already know a lot about astronomy -- one guest was an amateur astronomer from the east coast, on vacation. Some know almost nothing, such as the person who had to have it explained gently that we could not show very much in daylight because the sky was not yet dark. I am by no means an expert on supporting public programs, but I am beginning to have some tentative opinions on what to do.

A driven telescope certainly helps. I have worked without a drive, but it slows things down to have to keep checking that the object is still centered, it is hard to use high magnification on those objects that warrant it, and it is difficult to talk people through from bright stars to faint fuzzies, if the content and location of the field is always changing.

Long eye relief helps, too -- the Vixen Lanthanums are very nice in this regard -- if only because you don't have to worry about the need to refocus. I focus with my glasses on, and tell everybody else to leave theirs on, too.

There is no one correct eyepiece position for an audience that includes little kids and potential basketball players, but I would rather have an eyepiece on the high side, with a short ladder handy for people who need it. It is usually no problem for folks to step up, but elderly people may have difficulty bending to a low eyepiece position, and people dressed in expensive or constraining clothes may not want to kneel or stoop. It's also nice to have some way to rotate the eyepiece to an angle where users won't have to crane their necks too much -- either a rotating tube or a rotating star diagonal will accomplish that.

In the past, I have generally showed just "showpiece" objects that are handily placed, and I still do that if there are only a few telescopes present, but at occasions where there are lots of other folks presenting bright stuff, I have been using more difficult targets. I say, "Everybody else is showing you things that are easy -- I thought that maybe you'd like to see what it's like, pushing one of these telescopes close to its limits." People seem to find that intriguing. In July, 1998, at a public star party in a parking lot in Lassen National Park -- on a good night at 6000 feet, with everyone well dark-adapted -- I showed a 15th-magnitude planetary nebula in my Celestron 14, and with coaching about averted vision and careful explanation of exactly where in the field it was, about 80 percent of the newcomers got it.

The sky at Lick was not as dark, and I had only a five-inch refractor, so I chose a relatively easier target, the well-known galaxy NGC 7331, which was no problem at 92x. I had first chased down Stefan's Quintet, and was debating showing that, but decided not to -- the Moon had not quite set, and I was having trouble holding it myself.

Toward the end of the evening, I tried out a new eyepiece. I had recently gotten hold of one of University Optics's "7/70" Konig designs (that's "seven elements, seventy degree apparent field"), in 40 mm focal length and two-inch barrel, and was anxious to see how it worked. It was late, and I did not have time to make a careful comparison between it and the several similar eyepieces I have, but the 7/70 40 mm worked very well at the f/9 focal ratio of my Meade 127 ED refractor. At the 28x that it delivered, I could see a good deal of nebulosity in the Pleiades, not just the Merope Nebula. I also tried it with an Orion UltraBlock filter in the optical path, and was rewarded with lovely views of the east and west arcs of the Veil Nebula, and of the North American and Pelican Nebulae, too. I'll have to do an Enormous Eyepiece Evaluation Extravaganza at some future date.

Posted on sf-bay-tac Aug 31, 1998 20:23:04 PT
Converted by report.pm 1.4 Mar 21, 2006 20:45:31 PT