PST and Sun Spots?

Yesterday I had a chance to actually see the sun here in N. Calif.,
although somewhat briefly--Almost the first time in a month since buying
the scope. I noticed a dark spot and dismissed it as some oddity--maybe
dust on the lens. However, I noticed just before posting this that there is
mention of a huge sun spot visible. Is it in fact possible to observe
sunspots with the PST?
--
Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA)
(121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet

Web Page: home.earthlink.net/~mtnviews

"W. Watson" wrote in message
ink.net...
Yesterday I had a chance to actually see the sun here in N. Calif.,
although somewhat briefly--Almost the first time in a month since buying
the scope. I noticed a dark spot and dismissed it as some oddity--maybe
dust on the lens. However, I noticed just before posting this that there
is mention of a huge sun spot visible. Is it in fact possible to observe
sunspots with the PST?

Yes, it is - two ways:

If the tuner is slightly detuned the sunspots appear much as they would in
white light. Secondly, sunspots usually have some related activity which is
visible in the Ha bandpass.

Ed T.

W. Watson wrote:

Yesterday I had a chance to actually see the sun here in N. Calif.,
although somewhat briefly--Almost the first time in a month since buying
the scope. I noticed a dark spot and dismissed it as some oddity--maybe
dust on the lens. However, I noticed just before posting this that there
is mention of a huge sun spot visible. Is it in fact possible to observe
sunspots with the PST?

In looking over the Coronado site, they do claim sunspots. I'm pretty sure
I asked them about it a few months ago, and they said the opposite. Odd.
What's the difference in viewing between a whitelight filter and H-a? Is it
still useful to buy a whitelight filter?

Is there some reason the Coronado site doesn't have any solar images from
the PST? Where can I find some?

--
Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA)
(121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet

Most vehicle/deer accidents occur at sunset.
Vehicle deer whistles are ineffective.

Web Page: home.earthlink.net/~mtnviews

W. Watson wrote:
In looking over the Coronado site, they do claim sunspots. I'm pretty sure
I asked them about it a few months ago, and they said the opposite. Odd.
What's the difference in viewing between a whitelight filter and H-a? Is it
still useful to buy a whitelight filter?

It depends on the aperture of the hydrogen-alpha filter compared to the
telescope you're using it on.

I have a SolarMax 40 filter on a Televue Ranger (a 70 mm refractor). The
filter can be detuned from the center of the hydrogen-alpha band, and in
one direction, that detuning yields a view that is superficially very
much like that of a white-light filter, except of course that the image
is still hydrogen-alpha red. You just see the sunspots instead of other
solar detail.

However, that view is limited by the 40 mm aperture of the filter. A
full-aperture white-light filter for the Ranger, such as I had made from
Baader film before my son poked holes in it with his grubby little hands,
would yield better resolution. (It's all right, though. My principal
white-light solar scope is the C5+, so little harm done.)

Sunspots are more interesting at high magnification, so if you have
decent seeing and a larger aperture, it makes sense to buy or build a
white-light filter for it. It's so inexpensive by comparison with
hydrogen- alpha filters and scopes that it hardly makes sense not to.

Is there some reason the Coronado site doesn't have any solar images from
the PST? Where can I find some?

I thought I saw a couple; if I can find them, I'll forward pointers.

Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt

W Watty wrote:


In looking over the Coronado site, they do claim sunspots. I'm pretty sure I asked them about it a few months ago, and they said the opposite. Odd. What's the difference in viewing between a whitelight filter and H-a? Is it still useful to buy a whitelight filter?

Is there some reason the Coronado site doesn't have any solar images from the PST? Where can I find some?

Yes, it is possible to see sunpots with the PST. When on-band, the penumbrae
tend to get obscured by the mass of fine chromospheric detail (and the smaller
sunspots get very difficult to see), but you can still see the sunspot umbrae
fairly easily. The PST can also be de-tuned out of the H-alpha range giving
you a view which is very much like that using a white-light filter. The
resolution may be somewhat low due to the limited aperture of the PST, but it
still will show a surprising amount of detail. As for photography with the
PST, it is done but is not often as good as through the larger aperture
filters like the SM60 or SM90. In some of the older postings in the Solar
Observing section of the Forums on Cloudynights.com you will find some images
taken throught the PST. If you want to know what you might see in the PST, I
can generally see about as much with that scope as is shown by the wide-field
patrol "live" images on the Big Bear Solar Observatory web site when their
telescope is operating. Clear skies to you.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

You need to turn the tuning ring while looking through the scope to
explore the full range of it's capabilities. The PST is fully capable
of showing sunspots similar to what you'd see through an ordinary
"white light" filter.

On Mon, 17 Jan 2005 15:42:11 GMT, "W. Watson"
wrote:

Yesterday I had a chance to actually see the sun here in N. Calif.,
although somewhat briefly--Almost the first time in a month since buying
the scope. I noticed a dark spot and dismissed it as some oddity--maybe
dust on the lens. However, I noticed just before posting this that there is
mention of a huge sun spot visible. Is it in fact possible to observe
sunspots with the PST?



Robin Baker
Oregon City, OR USA

On Tue, 18 Jan 2005 11:02:16 GMT, "W. Watty"
wrote:

In looking over the Coronado site, they do claim sunspots. I'm pretty sure
I asked them about it a few months ago, and they said the opposite. Odd.
What's the difference in viewing between a whitelight filter and H-a? Is it
still useful to buy a whitelight filter?

There is a range of etalon adjustment using the tuning ring on the PST
where sunspots are most visible, somewhat similar to the view you get
with a white light filter. However, you do not see the same level of
surface structure surrounding the spots that you see in a white light
filter.

Is there some reason the Coronado site doesn't have any solar images from
the PST? Where can I find some?

There's a whole section of the Coronado Gallery devoted to PST images:

http://www.coronadofilters.com/cgi/d...gi?gallery=pst

---
Michael McCulloch

Michael McCullogh wrote:

However, you do not see the same level of
surface structure surrounding the spots that you see in a white light
filter.

The view with the PST "detuned" shows all the disk detail which a 40mm
white-light filter should show, with the exception of some faculae contrast,
which is better in a broad-band filter which has greater blue transmission.
Certainly, sunspots look just the same, with pretty much the same level of
detail as you would see with a 40mm diameter white light filter. That having
been said, a much less expensive and larger aperture white-light filter on a
larger scope would show more detail in the spots, as well as things like
granulation (visible in apertures larger than about 3.5 inches). Clear skies
to you.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

W. Watty wrote:

In looking over the Coronado site, they do claim sunspots. I'm pretty
sure I asked them about it a few months ago, and they said the opposite.
Odd. What's the difference in viewing between a whitelight filter and
H-a? Is it still useful to buy a whitelight filter?


I do see sunspots with my PST.

Is there some reason the Coronado site doesn't have any solar images
from the PST? Where can I find some?


There is a PST group on Yahoo with many PST images.

Likely sunspots are not featured because there are far more interesing
things to see with a PST.

Phil