Solar Prominence Viewing
Derk Drukker
Friday December 30 1994 03:12, Kevin D. Conod wrote to All:
>> cheapest) is a coronograph, as sold by Astrophysics in Illinois. The time
>> needed to record a prominence is 1/250th sec with the device. Detail is
>> very high even with a 80mm refractor, since you use the scope full
>> aperture.
KDC> Is this the same one as was reviewed in Sky & Telescope earlier this
KDC> year?
It is. It's a device from Baader Planetarium from Munich, Germany. I don't
like the owner very much, but they're extremely reliable and have developed
many accys for Celestron: Binocular viewer, Micro Guide eyepiece etc etc.
The prominence viewer costs DM 2000 for openings till 100MM. If you have a
bigger refractor, you need a red filter. The filters are measured by the Max
Planck Institute and are temperature stabilized: you don't need a filter
oven!
It's much better for prominences than other devices, but tyou can only see
prominences with them and the scope has to be polar aligned and operate at
solar speed, since the disk should be kept exactly behind the cone.
Greetings, Derk
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Derk Drukker
Friday December 30 1994 06:00, Jack Schmidling wrote to All:
JS> I called them today but no one was there who knew anything so I left a
JS> message. Would you mind explaining how it works and how cheap is
cheap?
In Germany, where mr. Wolfgang Lille fabricates them for Baader Planetarium,
Munich, they cost DM 2000. which is about $1200 Each device is hand made for
a specific wave length.If you want to use high magnifications you'll need an
off-axis viewing device that costs an extra Dm 250 or so.
JS> Maybe I put too much emphasis on photography. I have never even seen a
JS> preminence so I would settle for somthing visual till I get bored with
JS> it.
Since you use the refractor full aperture, you have much more detail in
prominences and the image is far brighter. 65% transmission I think. DayStar
has much less transmission, but is ideal for non-driven scopes and ideal for
people who want to study the surface of the sun.
JS> Is there any possible validity in Criterion claiming they do not need
JS> juice?
It's posssible, but the non-heated filters only work well when outside
temperatures are between certain specifications. Contrast is absolutely less.
Read the articles that Don Trombino wrote in Sky and Telescope magazine! He
tested the prominence viewer and wrote some articles on the DayStar device.
BTW: I have very postive experiences with DayStar!
JS> Forgot to call but I will tomorrow. How much is a filter like you
have?
I fear it will cost around $2500, not including a prefilter and mounting
accessories. They have a device called a T-Scanner that costs much less and
is not heated either.
JS> Finally, why does there seem to be no interest in this on the net or in
JS> the magazines?
First of all the cost of the filters. In Holland and Germany, there are
traditionally many solar observers, due to light pollution that keeps us from
observing deep sky objects well. There is a german magazine called "Sonne"
that is solely devoted to solar observers. Articles are in German, but the
most important pieces are also in english.
BTW: Baader also sells a Herschel wedge for around $600, that ets you study
the
surface of the sun in white light.