J-J Poupeau SHG from the 8th march

Post by **Merlin66** » Sun Mar 09, 2014 9:37 pm

Hello everyone,

Enjoying a clear view of the sky in Paris, I was able to obtain 4 spectroheliograms on lines H alpha, H beta, and CaK3 CaK1V and 1 dopplergramme Halpha.

http://img15.hostingpics.net/pics/99675 ... otuJPo.jpg

http://img15.hostingpics.net/pics/76763 ... Hb1JPo.jpg

http://img15.hostingpics.net/pics/74214 ... otuJPo.jpg

http://img15.hostingpics.net/pics/42273 ... 11VJPo.jpg

http://img15.hostingpics.net/pics/52312 ... lerJPo.jpg

Good transparency, moderate turbulence, moderate wind.

Image processing was carried out with the new software from Ph. Rousselle which provides quickly and easily spectroheliograms and dopplergrammes.

Here is the link: http://www.astrosurf.com/spectrohelio/d ... ncre_objet

Good day
J-J

Post by **marktownley** » Sun Mar 09, 2014 11:21 pm

Lovely shots!

That's what I want my CaK images to end up like...

Cschur · Post by **Cschur** » Mon Mar 10, 2014 2:04 am

Ken, I think the calcium bands are a good fit to the 2 Anstrom res of my unit. The difference between the two bands is exciting indeed.

Chris

Post by **Merlin66** » Mon Mar 10, 2014 6:01 am

Chris,
I believe J-J is using a 1200 l/mm grating and getting around 0.6A bandwidth.....

Post by **marktownley** » Mon Mar 10, 2014 6:45 am

Even if I triple stacked my CaK filters I can only get a FWHM of ~1.3a.

Here's an abstract question Ken, could a filter like this be used in conjunction with a spectroscope to reduce bandwidth still further?

Post by **Merlin66** » Mon Mar 10, 2014 6:50 am

Mark,
Good idea!
But the laws of physics are against you... the use of a CaK filter would just reduce the extent of the light into the slit but have no impact on the resolution....
SHG with longer focal length optics (larger plate scale= more mosaics...) would be required to reduce the resolution further.......

Post by **Merlin66** » Mon Mar 10, 2014 8:16 am

I just emailed J-J and he confirmed he's using a dispersion of 0.06A /pixel on his SHG!!!!!!!!!!!!!!
He also uses up to three pixel wide strips to "average" when preparing the SHG.
This effectively gives a bandwidth resolution of 0.2A.
Sounds like you still have some way to go Chris!

Post by **marktownley** » Mon Mar 10, 2014 10:22 am

Ahh fair enough Ken, i'm most definitely a noob in the field of spectroscopy

0.2a is pretty impressive, quite a way off from my 1.5a CaK setup though. Maybe one day i'll get into this spectroscopy lark. Is it possible to use them to take 'close up' images as well as full disks I take it?

Post by **Merlin66** » Mon Mar 10, 2014 6:54 pm

Yes.
It'd just a matter of scanning the slit over the area of interest and building the image....

Cschur · Post by **Cschur** » Mon Mar 10, 2014 9:14 pm

>>he's using a dispersion of 0.06A /pixel on his SHG!

You have to start somewhere!

Post by **Merlin66** » Mon Mar 10, 2014 9:17 pm

Agreed!
All journey's begin with the first step......

Cschur · Post by **Cschur** » Mon Mar 10, 2014 9:22 pm

Like Right Here:

: caACA.jpg (24.26 KiB) Viewed 2825 times

swisswalter · Post by **swisswalter** » Tue Mar 11, 2014 5:47 am

Hi Ken

thanks for the links, Yes fantastic discs, Filaments in CaK

J-J Poupeau SHG from the 8th march

J-J Poupeau SHG from the 8th march

Re: J-J Poupeau SHG from the 8th march

Re: J-J Poupeau SHG from the 8th march

Re: J-J Poupeau SHG from the 8th march

Re: J-J Poupeau SHG from the 8th march

Re: J-J Poupeau SHG from the 8th march

Re: J-J Poupeau SHG from the 8th march

Re: J-J Poupeau SHG from the 8th march

Re: J-J Poupeau SHG from the 8th march

Re: J-J Poupeau SHG from the 8th march

Re: J-J Poupeau SHG from the 8th march

Re: J-J Poupeau SHG from the 8th march

Re: J-J Poupeau SHG from the 8th march