Ca-H SHG full disk image with 90mm refractor -- Nov 25

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thesmiths
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Ca-H SHG full disk image with 90mm refractor -- Nov 25

Post by thesmiths »

There was a glimmer of unobstructed Sun through my upstairs window between 13:40 and 13:50 today. I took a small number of videos, from which I decided to stack three frames. This was the first time that I tried my 90mm aperture 910mm focal length Sky-Watcher refractor (with foam board SHG) for a wavelength other than H-alpha. Since the telescope is already around f10, I decided not to mask the aperture any further. It seems to have produced quite good resolution, despite not perfect conditions. It's not as good as what I've achieved previously with my more permanent setup using a 72mm aperture mask (and 720mm focal length), but that was shooting outdoors in the summer (and with more time to acquire data).

Ca-H SHG. 90mm aperture, 910mm focal length. 2400 l/mm grating. 9 micron x 12mm chrome on fused quartz slit. L1 UV/IR filter as ERF. ZWO 183MM camera, 2x2 binning. 8ms exposure, gain 111 (24%). 121 fps, scan 8X sidereal rate. FC2.7, AS!3, ImPPG, PS Elements.
Ca-H SHG. 90mm aperture, 910mm focal length. 2400 l/mm grating. 9 micron x 12mm chrome on fused quartz slit. L1 UV/IR filter as ERF. ZWO 183MM camera, 2x2 binning. 8ms exposure, gain 111 (24%). 121 fps, scan 8X sidereal rate. FC2.7, AS!3, ImPPG, PS Elements.
251122-CaH-910mm-2400g-stack-3.jpg (333.18 KiB) Viewed 1483 times

The tree-shaped protuberance on the left side is quite impressive. See some nice full disks from Pedro taken on the same day using traditional methods: viewtopic.php?t=38879

Ca-H protuberances. Single frame SHG, cropped and rotated.
Ca-H protuberances. Single frame SHG, cropped and rotated.
251122_134923_crop.jpg (80.82 KiB) Viewed 1476 times
Last edited by thesmiths on Sat Nov 26, 2022 2:04 am, edited 3 times in total.


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Re: Ca-H SHG full disk image with 90mm refractor -- Nov 25

Post by thesmiths »

Looking back at my Ca-H images from the summer, the image below is probably my best result, taken on a day with very good seeing:

Image
Ca-H SHG image. 720mm focal length, 72mm aperture. 2400 l/mm grating. 13x sidereal scan rate. Stack of 9 frames (out of 24).

The image comes from this post: viewtopic.php?t=37438.


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Re: Ca-H SHG full disk image with 90mm refractor -- Nov 25

Post by Alun_H »

Nice detail in the disk and in the prominences,you have given me the incentive to try my 90mm 900 focal length achromat with the Sol'Ex next clear sky I get.

Alun


Lunt 50THa solar scope
Lunt CaK B12 module
SW Evostar 72ED for full disk imaging
Sol'Ex SHG
80mm f/7 achromat used with pressure tune module off the Lunt with Lunt 100mm ERF
Bresser 90 f/10 achromat used for CaK & white light imaging & PST mod with Lunt 100mm ERF
Coronado SM40 (pre Meade) and BF10 filter set + SMII 60 richview DS etalon
Skywatcher EQ6 Pro and Ioptron CEM60
Then there is all the night kit which is far too long a list to write up here! :lol:
More images on view on my Flickr page...https://www.flickr.com/photos/alun_h/
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Re: Ca-H SHG full disk image with 90mm refractor -- Nov 25

Post by thesmiths »

The 90mm f10 works pretty well. I'm using it now because it's actually quite light so easy to move around indoors (!).


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Re: Ca-H SHG full disk image with 90mm refractor -- Nov 25

Post by marktownley »

This is an excellent set Douglas!


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http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
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Re: Ca-H SHG full disk image with 90mm refractor -- Nov 25

Post by Montana »

Incredible images Douglas, not only filaments but now prominences as well :bow :hamster:

I bought my first beginner hand held spectrometer last week. I have been looking at every light bulb with it and this weekend at the cloudy sky. I could see clearly the sodium doublet, hydrogen beta and iron. I was struggling to see the Halpha line but I did see it for a moment when the Sun came out a little, the sky does seem to need to be brighter to see this one. It is absolutely fascinating little toy, an early Christmas present.

Alexandra


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Re: Ca-H SHG full disk image with 90mm refractor -- Nov 25

Post by thesmiths »

Montana wrote: Sun Nov 27, 2022 7:50 pm I bought my first beginner hand held spectrometer last week. I have been looking at every light bulb with it and this weekend at the cloudy sky. I could see clearly the sodium doublet, hydrogen beta and iron. I was struggling to see the H-alpha line but I did see it for a moment when the Sun came out a little, the sky does seem to need to be brighter to see this one.
The handheld spectrometers are great. As I recall, you can point directly at the Sun and the lines really jump out. If you have one of the fisheye lenses that come with the ZWO cameras, I think you can put this lens right up to the eyepiece of the spectrometer and record the spectrum with the camera (monochrome is easier).

Another cute spectrometer experiment is to drop some salt (sodium chloride) onto a candle or the gas hob and the sodium doublet is super bright. Kitchen science!


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Re: Ca-H SHG full disk image with 90mm refractor -- Nov 25

Post by Montana »

Thanks for that tip, I didn't realise you could shine it at the Sun (don't want to blind myself). I'll definitely try the salt on the gas hob tonight, the Hubby already thinks I am weird so it won't come as a surprise :lol:

Alexandra


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Re: Ca-H SHG full disk image with 90mm refractor -- Nov 25

Post by Montana »

I had great fun this evening while the Hubby was cooking tea, it was fabulous, the sodium line is amazing!! I really enjoyed myself until I got told off by the Hubby for making a mess. Tea was lovely so I can't complain :)

Alexandra


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Re: Ca-H SHG full disk image with 90mm refractor -- Nov 25

Post by Montana »

I tried the spectrometer on our candles the other night, we noticed that the advent candle had a really strong sodium line in it but the other candles were all an even spectrum. Intrigued a looked up on google 'salt in candles' and found that adding salt to candles makes them non drip. Interestingly, we had already noticed that the advent candle doesn't drip like the other candles. It is so educational, I feel I have made quite a discovery :hamster: I wouldn't have recognised the sodium line if I hadn't done the messy salt on the hob experiment :) Thank you!

Alexandra


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