Search found 953 matches

by p_zetner
Thu Sep 19, 2019 12:09 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: 14May2019 Spectroheliograms: H alpha
Replies: 9
Views: 169

Re: 14May2019 Spectroheliograms: H alpha

Thanks for your comment and kind wishes, Bart! The optics train is long but pretty sturdy. One thing about this type of spectroheliograph is that, generally, it doesn’t need to track. It remains stationary as the Sun “sweeps past”. I think, because of that, there’s more tolerance of flexure and othe...
by p_zetner
Wed Sep 18, 2019 8:42 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: 14May2019 Spectroheliograms: H alpha
Replies: 9
Views: 169

Re: 14May2019 Spectroheliograms: H alpha

Hi Alexandra. Thanks for the kind comment. I've attached a picture which gives a brief idea of how the dopplergram is constructed and what it shows. The explanation is a bit sparse but, hopefully, the idea comes through. Unlike a regular image in which the grayscale variations are due to the brightn...
by p_zetner
Mon Sep 16, 2019 1:57 pm
Forum: This is SolarChat !!
Topic: 14 May 2019 Spectroheliograms
Replies: 15
Views: 232

Re: 14 May 2019 Spectroheliograms

Thanks very much, Alexandra!

All the best to you.
Peter
by p_zetner
Sun Sep 15, 2019 3:22 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: 14May2019 Spectroheliograms: H alpha
Replies: 9
Views: 169

Re: 14May2019 Spectroheliograms: H alpha

Hi Mark. So far, I haven’t used any front filtering on the C4 but I’m thinking about it. In the previous incarnation of this SHG, I used a Rubinar 100mm f/10 which had some cemented field correcting lenses at the back end. I used a 100mm x 100mm Schneider IR-UV cut filter to try and reduce the therm...
by p_zetner
Thu Sep 12, 2019 9:31 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: 14May2019 Spectroheliograms: H alpha
Replies: 9
Views: 169

14May2019 Spectroheliograms: H alpha

Hi Everyone. I've posted a teaser collage of the Sun in four wavelengths in the main forum. https://solarchatforum.com/viewtopic.php?f=4&t=26584&p=239629#p239629 I thought I would add some more images here and start with H alpha. The first three images are, in order, full disk H alpha spectroheliogr...
by p_zetner
Thu Sep 12, 2019 9:09 pm
Forum: This is SolarChat !!
Topic: 14 May 2019 Spectroheliograms
Replies: 15
Views: 232

Re: 14 May 2019 Spectroheliograms

Dear Frank, Phil, Valery, Mark, Stu, Eric and Maurits; Thanks all for your kind thoughts and supportive words. Eric, you may be right about the healing power of solar astronomy! Stu, I'll do my best to stick around for a few more solar cycles. I have projects I have to finish! Thanks again and all t...
by p_zetner
Wed Sep 11, 2019 8:37 pm
Forum: This is SolarChat !!
Topic: 14 May 2019 Spectroheliograms
Replies: 15
Views: 232

Re: 14 May 2019 Spectroheliograms

Marty, Franco and Pedro; Thanks for the very kind wishes.
It’s good to be among the living, hopefully long enough to outlast solar minimum!
by p_zetner
Wed Sep 11, 2019 6:40 pm
Forum: This is SolarChat !!
Topic: 14 May 2019 Spectroheliograms
Replies: 15
Views: 232

14 May 2019 Spectroheliograms

Greetings Everyone. These spectroheliograms are a bit late in coming . They were taken in May when we had the rare pleasure of the large sunspot and active region AR2741. The disk orientation is wrong - probably inverted left to right. In the intervening time, I had the opportunity to do some travel...
by p_zetner
Sun Aug 25, 2019 12:55 pm
Forum: This is SolarChat !!
Topic: Saturday Sun Aug 24th
Replies: 13
Views: 210

Re: Saturday Sun Aug 24th

Very nice views, Stu.
Superb work on the granulation images.
Cheers.
Peter
by p_zetner
Sun Aug 25, 2019 12:53 pm
Forum: This is SolarChat !!
Topic: Descending Prominence Knots and Coronal Rain - 23rd August
Replies: 20
Views: 278

Re: Descending Prominence Knots and Coronal Rain - 23rd August

Superb animation and terrific post, Mark.
Cheers.
Peter
by p_zetner
Wed Jun 12, 2019 5:29 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: can someone explain double reversal?
Replies: 3
Views: 324

Re: can someone explain double reversal?

Hi John.

I replied to your question here:
https://www.cloudynights.com/topic/6645 ... nd-k-line/

I also addressed the nature of the double reversal on the SolarChat forum:
viewtopic.php?f=8&t=12329
(Near the end of the thread.)

Cheers.
Peter
by p_zetner
Tue May 21, 2019 4:26 pm
Forum: This is SolarChat !!
Topic: May 17: AR2741 and proms in H alpha
Replies: 6
Views: 340

May 17: AR2741 and proms in H alpha

Hi Everyone. Saying goodbye to AR2741! High resolution image: Aries ERF, Celestron C8 Edge, Moonlite CHL focuser, ~f/46 Telecentric, Daystar QPE 0.6A, PGR USB3 Grasshopper IMX174 Mosaic (4 panels): Aries ERF, Celestron C8 Edge, Moonlite CHL focuser, ~f/46 Telecentric, Daystar QPE 0.6A, ~f/30 FR, PGR...
by p_zetner
Fri May 17, 2019 2:21 am
Forum: This is SolarChat !!
Topic: AR12741 at it's full opening in H-a and CaK high resolution with C11 and C8 scopes.
Replies: 7
Views: 454

Re: AR12741 at it's full opening in H-a and CaK high resolution with C11 and C8 scopes.

Astonishing imaging, Valery.

Look at the details in the light bridge! You give adaptive optics a run for its money.
I can’t believe you were able to stack 3000 / 4000 frames! Were these “real time” quality selected by SSM?

Cheers.
Peter
by p_zetner
Fri May 17, 2019 1:56 am
Forum: This is SolarChat !!
Topic: AR2741 High Res, Proms | HA, WL, CaK | May 15th 2019
Replies: 7
Views: 421

Re: AR2741 High Res, Proms | HA, WL, CaK | May 15th 2019

Another nice collection, Marty.
You really manage to get the most out of a session!

Cheers.
Peter
by p_zetner
Fri May 17, 2019 1:48 am
Forum: This is SolarChat !!
Topic: AR2741 2019/5/16
Replies: 5
Views: 351

Re: AR2741 2019/5/16

Another excellent view of the AR, Pepe.
The prom shot looks good too.

Cheers.
Peter
by p_zetner
Fri May 17, 2019 1:44 am
Forum: This is SolarChat !!
Topic: Close to AR2741 ... Quark Prominence ... UPDATE
Replies: 13
Views: 659

Re: Close to AR2741

Beautiful shots, Maurits.

I love inverted disk views. I don’t know whether it’s psychological but they seem to reveal more detail.

Cheers.
Peter
by p_zetner
Fri May 17, 2019 1:41 am
Forum: This is SolarChat !!
Topic: May 15 H alpha and May 10 CaK
Replies: 11
Views: 550

Re: May 15 H alpha and May 10 CaK

Thanks everyone. Here I thought the gods of meteorology were just picking on me! A hazard of the hobby, clearly! (Hmmm....”clearly”...) Bart: I’ve been very lazy about recording my exposure settings lately. The CaK shots are probably around 5ms. I try to keep it as short as possible without boosting...
by p_zetner
Thu May 16, 2019 11:14 pm
Forum: This is SolarChat !!
Topic: Thursdays Hazy Start to the Day - 16th May
Replies: 11
Views: 544

Re: Thursdays Hazy Start to the Day - 16th May

Nice shots, Mark. They do stand up well under magnification.
@RodAstro: I wonder if a little haze is beneficial. It does seem to be associated with less turbulence. In the end, though, I guess there is some sacrifice of fine detail.
Cheers.
Peter
by p_zetner
Wed May 15, 2019 5:23 pm
Forum: This is SolarChat !!
Topic: May 15 H alpha and May 10 CaK
Replies: 11
Views: 550

May 15 H alpha and May 10 CaK

Hi Everyone. I should have paid more attention to the weather forecast. The day began with beautiful clear skies (not a cloud in sight) so I began the process of gearing up for an imaging session. I set up the C8 scope and, as the Daystar came to temperature and the Sun cleared the neighbour's tree,...
by p_zetner
Wed May 15, 2019 5:08 pm
Forum: This is SolarChat !!
Topic: AR2741 2019/5/15
Replies: 5
Views: 303

Re: AR2741 2019/5/15

Beautiful images, Pepe.
I like your idea of showing the increased exposure image to reveal structures in the spot.
Cheers.
Peter
by p_zetner
Wed May 15, 2019 1:12 pm
Forum: This is SolarChat !!
Topic: Sunday sunshine 12th May
Replies: 10
Views: 459

Re: Sunday sunshine 12th May

Wow, the H alpha closeups are terrific, Alexandra.
The double stacking really produces a nice result.
Hope your little Grasshopper returns home soon!
Cheers.
Peter
by p_zetner
Wed May 15, 2019 2:05 am
Forum: This is SolarChat !!
Topic: Always to see something ...
Replies: 9
Views: 427

Re: Always to see something ...

Very nice image, Maurits.
Cheers.
Peter
by p_zetner
Wed May 15, 2019 1:55 am
Forum: This is SolarChat !!
Topic: AR2741 & AR2740, Large Prominence | HA & CaK | May 14th 2019
Replies: 5
Views: 328

Re: AR2741 & AR2740, Large Prominence | HA & CaK | May 14th 2019

Lovely set, Marty.
Lots of detail in the closeup even though it’s “only” 120mm aperture!
Cheers.
Peter
by p_zetner
Tue May 14, 2019 5:58 pm
Forum: This is SolarChat !!
Topic: AR2741 with 250mm RCT
Replies: 14
Views: 611

Re: AR2741 with 250mm RCT

Excellent image, Stu.
Looks like great potential for hi-res images with that scope.
Cheers.
Peter
by p_zetner
Tue May 14, 2019 1:31 am
Forum: This is SolarChat !!
Topic: Sol from the 13th of May 2019.
Replies: 8
Views: 343

Re: Sol from the 13th of May 2019.

52 years! Wow!! Congratulations, Eric. That’s quite something.
(You really managed to produce some beautiful disks also, despite the conditions.)
Cheers.
Peter