What does the sun look like in Coronado?

[emadmoussa]

I've seen a lot of nice pictures taken through this solar telescope, and I saw a bunch of people huddled up around one at StroCamp. But still I don't know what the sun actually looks like ''visually'' in Coronado. How far off is it from the images?

Just curious...not thinking about solar imaging any time soon

[foundaplanet]

I can't answer the question about the Coronado, I did look through a Double stack Lunt 60 at EMS 2 though and to say I was blown away is an understatement. I think I would have to say it was equal to my first ever view of Saturn through a scope, if not better. Yes that was very close to the images though not as big. A day I will never forget..

[brantuk]

It's pretty much like the pics Emad. In fact depending on the magnification, and whether or not the scope is double stacked, the pics can reveal more detail. But basically you get an orange/red disk and the prominences on the limb are clear to see if it's well tuned and focused.

Some solar scopes will show considerable surface detail - it looks generally like a bubbling orange porridge with loads of dark fissures/cracks all over the place of varying lengths. Some of these are sun spots (often grouped) but when they come round to the limb you notice they are massive flares or solar ejections several times the size of Earth.

You really should get to a star party and have a look through one - the view can be awesome in the larger scopes (120mm, 150mm, etc) especially when there's a lot of activity. I could spend all day looking at the sun and often have done.

[emadmoussa]

Aha, I see. If you use a ''solar filter'' with a 6" refractor, will it produce enhanced images? And how is that compared to a custom built scope like the Coronado?

[JamesF]

Agreed.  The detail you can see is impressive even with the 40mm aperture of the PST.  Ha scopes restrict the view to a very narrow band of light centred on the first Hydrogen alpha emission line which is in the red part of the spectrum, so the image is effectively monochrome red.

There are also CaK solar scopes that show a different image because the emitted light originates from another part of the Sun's atmosphere.  Few people on SGL seem to have such scopes and images from them are not often posted.  I'm not even sure that it's possible to buy a CaK scope off the shelf any more.

James

[JamesF]

Aha, I see. If you use a ''solar filter'' with a 6" refractor, will it produce enhanced images? And how is that compared to a custom built scope like the Coronado?

A white light filter works completely differently.  You get a small percentage of all frequencies passing through the filter, so you see a white/grey image.  It is possible to pick up details in the sunspots, faculae and sometimes pick out "surface" granulation, but I'd say the detail doesn't come close to what you get in Ha.  You can't pick out proms with white light either.

James

[emadmoussa]

A white light filter works completely differently.  You get a small percentage of all frequencies passing through the filter, so you see a white/grey image.  It is possible to pick up details in the sunspots, faculae and sometimes pick out "surface" granulation, but I'd say the detail doesn't come close to what you get in Ha.  You can't pick out proms with white light either.

James

Thanks. This makes a lot of sense Maybe some day!

[Luke]

Some YouTube videos here "live" with a H-a scope, I think they give a rough idea:

http://www.youtube.com/watch?v=1C6L0upbZSA
http://www.youtube.com/watch?v=FzYnAXiaMzY

For me, the processed images never look quite the same as what you see at the eyepiece, I'm not sure why

When there are some good sunpots around, I enjoy white light viewing in my ED100 or ED120 plus Herschel wedge and solar continuum filter almost as much as hydrogen alpha viewing. H-a and white light complement each other really well. My Lunt 1.25 inch Herschel Wedge was a fraction the cost of my 60mm H-a scope, so if you already have a nice compatible refractor (best to check your scope is okay - some have correcting elements I believe that are not safe be used with a wedge), you can have a pretty awesome setup for solar viewing without busting the bank

I hope Montana doesn't mind me linking to her incredible white light photos on Flickr, taken I believe with a 140mm scope, Baader Herschel Wedge and continuum filter:

http://www.flickr.com/photos/alexandra4/sets/72157628535703357/

And of course, there's the Baader solar film, which is a bit less sharp than the Herschel Wedge and solar continuum filter, but is amazing value.

If you're tempted with solar, sooner might be better than later. Solar activity you can see in H-a or white light will really quieten down in a few years as we head towards the solar minimum. There could be weeks/months of no visible sun spots, though apparently you can still see facculae in white light, and get some good proms in H-a, during the quiet period (I've not been through the minimum yet as a solar observer).

[AndyWB]

I've seen a lot of nice pictures taken through this solar telescope, and I saw a bunch of people huddled up around one at StroCamp. But still I don't know what the sun actually looks like ''visually'' in Coronado. How far off is it from the images?

What, Astrocamp a few weeks ago? In the Brecon Beacons? That might've been me! I was curious too, never having seen the sun though one. My thoughts were:

- It's very red. I mean, we're talking monochrome; different shades of red. I gather many photos (the more orange ones) are actually false colour.

- I could see filaments, prominences, and a kind of swirly graininess on the surface. It was quite fascinating, and seemed to change nearly while you watched.

- It kinda looked like what's shown here: http://www.virtualcolony.com/sidewalk/

- The brightness light of the Sun was a problem when looking at the Sun - both glare generally (though not through the scope), and the need for some sort of dermally applied UV filter.

I was surprised - in a way I couldn't see the point of solar astronomy. I mean, you've only got one thing too look at, and it only has sunspots, right? Now, however, a solar scope is on my 'one day, if I get a bonus' list - and I didn't see any sunspots!

I also looked through a Lunt 60 solar scope that Neil from Tring Astro had brought along. It was gorgeous - a much better image than the PST to be honest - but much more expensive. Delphelis took some nice images through it (Note: false colour again) http://www.flickr.com/photos/dephelis/9724839084/

[JamesF]

- It's very red. I mean, we're talking monochrome; different shades of red. I gather many photos (the more orange ones) are actually false colour.

Indeed so.  Although the Ha emission line is in the red part of the spectrum (656.28Nm), most people are probably imaging with a monochrome camera and thus get a greyscale image.  In theory I guess one could render that greyscale image in tones of the original wavelength, but most people go for a more orange bias.

James

[AndyWB]

In theory I guess one could render that greyscale image in tones of the original wavelength, but most people go for a more orange bias.

Yup, that's my thought. It does look more 'natural' with the orange, even though it's completely wrong