Re: ATM Advise, please...

[Dwight Elvey <elvey@hal.com>]

Bob Prabowo <BOB@bahana.co.id> wrote:
> 
> Now I need your advise on the followings:
> 1. Can I use a Newtonion telescope on Dobsonian mount for solar
> observing? Will an equatorial platform work for this kind of set up (the
> scope will be left unattended for hours)? Or does the scope have to be
> equatorially mounted? 

Hi Bob
 I would think that it would be best to not use the same
telescope for both purposes. For night use, the 13 inch would be
best but there is no way to deal with the mounting.
A platform mount would be unusable because you'd need to tend
it regularly and re-align the telescope as well. Most
platforms are about one hour or so between adjusting.
You could make a EQ mount that the tube would clamp to
but a EQ mount for a 13 inch is vary large.
The scope size needed for solar observing could be a small
refractor of about 100-115mm. This would do well. I would
also suggest making a heliostat with a mirror to redirect
the solar image. This simplifies the entire arrangement
and leave room in the dome for a night time telescope for
other uses.
so:
1. Wouldn't recommend a Dobson for unattended use.
2. 4 inch would work well.
3. I remember him but would have to look thru back issues.
   It wouldn't be practical for a large telescope because
   of the cost of clear tube that size. 3 or 4 inch would
   be OK. You couldn't run the see thru demo at the same
   time as used for solar because all of the solar filters
   require a pre-filter. In the article, he had to use
   smoke to even make the beams visible. This would be
   much better as a demonstration scope in an exhibit.
4. I would recommend that the system have two filters.
 one a wide band prominence filter and a narrow one for
 surface detail. The prominence filter would require vary
 little attention but the surface filter needs regular
 tweaking to stay tuned. Prominence filters are about $500us
 and narrow band filters are $1500-$4000 someplace.
Dwight