Lasers and binoculars

[Charlie in Dayton]

Saturday evening August 19 was the second-to-last Camper Stargaze at John Bryan State Park for the 2006 season (the final one is Labor Day weekend, Saturday September 2...and I'll be at my 35th high school reunion...). We had a relatively small turnout of campers (things kinda trickle to a halt by the end of the summer), but the three telescopes and binoculars we had did get a workout.
I've been telling myself I've got to get a laser pointer to make things a bit easier for my binocular astronomy demo at these events. Turns out that MVAS has one out at JBSPO, so I got permission to borrow it for some of our show'n'tells. Now I am convinced I need one of my own...it works so well to point out things to beginnning stargazers.
Once an object is selected, everyone can gather around the laser holder, who points it into the sky while everyone is looking thru their binos. Everyone is close enough to the center that it's like they are the ones doing the pointing, and it's easy for them to track the beam. We were able to successfully pick out Mizar/Alcor (and demonstrate that Mizar itself is a double), the Double-Double in Lyra (and the story that each double was itself a double got some ooh's), the Coathanger (Collinder 399 -- that drew some laughs), and M31 (I have a schtick about gazing 2 1/2 million years into the past, and welcoming the stargazers into the ranks of time travelers). With a steady hand, the laser holder can look thru their binoculars (my pair is 7x50's, everyone else has 7x35's...rank hath its privileges) and actually draw out the object in the sky for others to pick out. It works nicely.
If you're teaching binocular astronomy, a laser pointer is a good tool.

This post has been printed in a modified form as part of an article in the September 2006 edition of the Miami Valley Astronomical Society newsletter "The Amateur Astronomer"

[Dave Mitsky]

Charlie,

I uinderstand very well the potential advantages of using green laser pointers in amateur astronomy. However, amateur astronomers have been teaching folks the night sky for a long time without their use. IMO, children who see them in operation are far more fascinated by the lasers than whatever celestial object they are highlighting. Will they be able to find that object again without a laser shining at it? Not if they aren't taught rudimentary star hopping and chart reading.

GLPs have become a controversial subject in amateur circles. A number of major star parties forbid them. Astrophotographers/imagers hate them since they can ruin their painstaking work. It is easy nowadays to purchase GLPs with outputs far above the legal 5mw limit, thus increasing the chances of tragic accidents.

I've seen too many cases of misuse to condone the use of GLPs. One of my star party friends was flashblinded by a laser at the 2004 Black Forest Star Party. He suffered vision problems for months afterwards.

I've had close calls personally at Stellafane several years ago and at the 2005 Green Bank Star Quest and have had words with a fellow astronomy club member who is very irresponsible with his laser on more than one occasion.

Dave MItsky

[Charlie in Dayton]

Your concerns are well noted and understood, Dave. As someone who has some (not much, but some) experience in optics and laser light, I exercise extreme caution.

Nobody uses it but me.
At a new site, I ask if it's permissible to use it before it comes out of the box.
If I'm not using it at the moment, it's in my pocket.
It gets pointed at stars -- period.

And I rely on it solely for the occasional assist. not a be-all-to-end-all in itself.


Between you'n'me, common sense oughtta take care of all concerns...