When you want to see the stars, find someplace dark
A few years back I posted the design of a Sun finder. With the eclipse looming it is time to highlight that post again. Aiming your telescope or camera at the Sun can be a nuisance. A problem with a really simple solution.
I would suggest light cardboard, the type used in a cereal box, and some masking tape that will peel clean off your telescope or camera. Just line up the telescope once and mark the dot of light’s position with a pen… Done.
In the end it is a Celestron C8 telescope drive and forks containing custom electronics, a Meade heavy duty wedge from an LX-90, a hand-made tripod, holding a Televue 76mm APO telescope, using a Vixen style dovetail base, with a Baader film solar filter.
It is tempting to call it Frankenscope after the similarities with the classic monster.
To further add the the Mary Shelley plot similarities, much of this was revived from the junk pile. I very nearly decided to toss the drive and fork, they were that bad, peeling paint and rusty bolts. A great deal of work was necessary to re-animate these components.
The wedge came from a telescope that was killed in an unfortunate incident with an aquarium heater. The heater was used to de-humidify the OTA and prevent fungus on the optics. Note: Aquarium heaters are not made to operate out of water.
Several new aluminum parts were machined from scraps, some of which were scavenged when the observatory shop was being cleaned out and a lot of metal stock was tossed.
Many of the electronic components used to build the drive corrector were also scavenged parts from dead electronics, this includes the 1.8432MHz crystal that forms it’s beating heart. This heartbeat keeps the mount turning at exactly sidereal rate.
Yeah, you could call it Frankenscope.
But I will call it Hodgepodge.
A few days ago I looked at the solar imagery from the spacecraft and ground observatories and feared that our Sun would be completely spotless for next week’s solar eclipse. The one sunspot visible had just rotated out of view, not to return until well after the eclipse. There were no other sunspots apparent.
Sunspot group AR2671 formed on the eastern limb of the Sun over the last couple days. It has even produced a few c-class solar flares to show it has some vigor.
Better yet… This sunspot group will be a boon to eclipse photographers across the US. The pattern of dark spots will make the difficult task of focusing a telescope on the Sun far easier. These spots will provide a focus target to untold telescopes.
The only question now is will the group last for five more days? Will is grow or shrink.
What will the Sun look like when eclipse day arrives on August 21st?
Very quiet!
I observed this spot several times while training some folks at the observatory to use a solar setup and while testing my eclipse telescope.
AR2670 is now disappearing from sight as it rotates over the limb, maybe it will be back in another couple weeks for a third appearance.
Checking the SOHO image archive and the GONG farside maps shows there is nothing else, no significant solar activity that will appear before the total eclipse in eight days. Nothing hiding on the farside to rotate into sight.
There is a slim chance of something new developing over the next week. However, we are approaching solar minimum, a quiet Sun is to be expected. Indeed, I expect we will have an almost featureless solar disk on eclipse day.
Update 14 Aug 2017: With one week to go a new spot has appeared! I do not see that is has an AR designation yet, but this new spot should be in the middle of the Sun on eclipse day if it lasts for the week. It may not be big or pretty, but it will at least give everyone something to focus cameras on in preparation for the main event.
Update 15 Aug 2017: The new sunspot has been designated AR2671 and has already produced some C class flares. Looks like has the energy to develop a bit more. At least one small sunspot for the eclipse?
When travelling to an eclipse, one solar filter is not enough. I need a backup!
Having the two filters available for use mean I must choose between them when the moment is critical. Which is better? Some testing is in order to find out.
The two filters appear very different, the thin silver film of the Baader quite different than the thicker black polymer film of the Orion filter. Both filters are safe to use and provide decent solar viewing. Both provided pleasing solar images using my Televue 76mm APO telescope at low and medium power.
Stepping beyond basic use I do find that they perform quite differently. So differently I felt some notes are in order.
For this solar eclipse I will be in the middle of central Oregon, a long way from any stores, much less an astronomy equipment store. I will have to have everything I need on-hand, nothing forgotten, nothing overlooked.
A checklist is certainly in order!
The checklist below was compiled as much for myself as anyone who might read this posting. Actually writing the checklist out is quite useful as a personal double check. I need to consider that we will be camping for several days prior to the eclipse, that time will be spent hiking, stargazing, or simply relaxing in the forest with family.
A tricky shot, taking very precise timing and navigation. I can not claim credit, Sean Goebel did the planning. I just supplied scouting information and came along for the ride.
Given that this only involved a fifteen minute drive from the house for me… Why not? Give it a try. Besides, I already had a suitable telescope loaded in the vehicle.
Yes, it is a telescope on a beach…
