Amateur solar imaging and technique discussion

[davenn]

07 Feb 2018, The Sun in Ha ...
Lunt LS60THa, ASI 1600MM camera and SharpCap software.
These are single frame images (no stacking)

https://www.facebook.com/photo.php?fbid=152900435412664&set=pcb.152900485412659&type=3
finally a reasonable spot group. The best for many months

cheers
Dave

 

[davenn]

10 Feb 2018, The Sun in Ha ... The very respectable sunspot group ( largest for at least 4 months) has moved further onto the disk and is displaying some good details. Lunt LS60THa, ASI 1600MM camera and SharpCap software. These are single frame images (no stacking)

the second image is closeup of the active region, the best for some months, the black sunspots can be seen along with the bright areas of flaring between them

cheers
Dave

 

[davenn]

The Sun in Ha, 3 March 2018

Been a couple of weeks since I last got a chance to do some solar observing/imaging some Ha images from today. One very large prominence and some filaments ... Lunt LS60THa and a ASI1600MM camera

Dave

 

[Stavros Kiri]

Awesome!
Some colour next time? (I like both)

 

[davenn]

hi guys and gals

for those interested in solar observations and imaging, I have found a very useful tool for determining the size of
features on the sun eg. sunspots, filaments and prominences etc

I present the Solar Ruler, available here ...
https://samuelastronomy.wordpress.com/tag/solar-ruler/

there is an English version here ...
http://thesolarexplorer.net/index.php/tutorial/article2/article2/the-solar-ruler
the download link is right at the bottom of the page

This is a PDF file that you load into your fav image processing program that is able to support the manipulation of layers when combined

For me, I use Photoshop (PS). I load in my solar image and I load in this PDF file they are in separate tabs at the top of the image viewing area

I resize the solar ruler image to equal the size of my solar image as close as possible, then I copy it and paste it over the top of the solar image.
I then use the move function to move the solar ruler image around so I can align it with the solar image to produce this result

Solar image is the first image from my previous post ...

NOTE: the image is seriously reduced in size and quality to be able to post on this forum

You can see I managed to get the solar and ruler image sizes to match reasonably well

I can now quickly determine the approx. size of that big prominence ... ~ 60,000 - 65,000 km in height above the suns disk !

Quite impressive
hope some finds this useful

Dave

 

[Stavros Kiri]

for those interested in solar observations and imaging, I have found a very useful tool for determining the size of
features on the sun eg. sunspots, filaments and prominences etc

hope some finds this useful

Some day I hope (for me) ... . Sounds like great tool!

65,000 km

Ah, a bit less than twice the perimeter of the earth! ... Ok, No big deal! ...

 

[davenn]

Ah, a bit less than twice the perimeter of the earth! ... Ok, No big deal! ...

perimeter isn't the important measurement, it is almost 5x the diameter ... that's the important value

remember we are looking at length of prominence say 60,000km round figures
diameter of the Earth 12,700 km round figures. The Earth fits INTO that prominence 4.7x ( 5x if you go out to the 65,000km measurement)

Three Earths side by side will fit through that dark centre part of the loop...

now that is significant

Dave

 

[Stavros Kiri]

now that is significant

I think it's significant anyway! Also it's ~ 1/6 of the distance Earth-Moon ! ...
[The "no big deal" was a joke ...]

(+ light takes about 1/5sec to travel it! ... That means relatively HUGE distance! ...)

 

[davenn]

Haven't been able to do any solar imaging for a bit over a month, mainly due to cloudy skies and or lack of activity on the sun
I could have imaged last Saturday 7th April very clear sky and some good prominences.
Only problem was that it was 35C outside and the heat was unbearable to be in for more than a few minutes,
let alone the amount of time to set up the scope and computer and do imaging. That would have taken at least 30mins,
28 - 29 mins more than I was prepared to endure

How does an astronomer overcome bad condition "blues" ... buy some more gear

So here is my new scope ... A Skywatcher EVOSTAR120 Black Diamond refractor
120mm objective lens and a 1000mm focal length giving a f-stop of 8.3
f-stop (ratio) = FL / aperture = 1000 / 120 = 8.33333...

It's been around 45 years since I last owned a refractor scope (discounting finder scopes)
This scope will get used for visual observing and imaging of solar, planetary, lunar and deep space
The camera in the photos below is the ZWO ASI 1600MM

Visual observing setup ... eyepiece and diagonal...

visible light imaging...

Solar Ha imaging through a Daystar Chromospheric filter...

close-up of the filter and imaging setup...

cheers
Dave

 

[sophiecentaur]

Hi @davenn Nice stuff. Sorry to hear about the weather. It would be nice to have a bit of Sun 'up here' too.
How easy is it to shift that 120mm refractor about? I have a lumpy 8" Newtonian and it's a pain to get it up and onto the mount. No wonder I tend to use my 80mm Equinox nearly all the time. I look around me and 'everyone' seems to be buying or making garden observatories which solve the lifting problem. But the only suitable site for one in my garden is too much in the faces of people using the garden for non astronomical purposes.

 

[davenn]

Hi @davenn Nice stuff.

cheers

Nice stuff. Sorry to hear about the weather. It would be nice to have a bit of Sun 'up here' too.

lots of sun, but it's been mainly during the week days when I am at work and now that we are getting well into autumn, the days are getting shorter and daylight saving ended easter weekend so the sun is too low in the west for me to observe by the time I get home from work.
Weekends are my only chances for solar observing now.

How easy is it to shift that 120mm refractor about?

quite light the tube, mounting rings and that green mounting bar total around 5.5kg

I have a lumpy 8" Newtonian and it's a pain to get it up and onto the mount. No wonder I tend to use my 80mm Equinox nearly all the time

yeah, I know that feeling with my Celestron 9.25" Schmitt-cass ... It's quite heavy

But the only suitable site for one in my garden is too much in the faces of people using the garden for non astronomical purposes.

a home observatory is out of the question for me
1... primary reason ... I'm renting the property
2... I'm deep in the red zone of light pollution for doing nite time astronomy

Back in NZ, I had a 2.5 x 2.5m garden shed obs. that I made the roof roll off

use my 80mm Equinox

just googled it, nice looking scope does your one have the 10:1 Crayford fine focuser ?
http://www.skyatnightmagazine.com/review/telescopes/sky-watcher-equinox-80-ed-apocheers
Dave

 

[sophiecentaur]

2... I'm deep in the red zone of light pollution for doing nite time astronomy

Can't win 'em all. It's not too bad here as there are no street lamps and the only pollution is from some garden lighting next door (she is security mad). My astrophotography efforts are put to shame by some club members who live close into London. The worse the conditions, the more nerdy you have to be. My problem is I have problems with the cold and laziness, limited budget and some other spending priorities. Some of your solar pictures are good justification for your spending, though.
BTW, what sort of solar energy rejection filter can you use with your 120mm? I thought there were limits to objective sizes for 'rear end' filtering. I have a shiny Baader filter for my 80mm objective but that is a poor man's solution to solar, I think.

 

[Stavros Kiri]

How does an astronomer overcome bad condition "blues" ... buy some more gear

Lol ... That always works, doesn't it?

 

[NFuller]

So here is my new scope ... A Skywatcher EVOSTAR120 Black Diamond refractor

Nice choice, Skywatcher has been known to put out some good equipment for a reasonable price. I actually just purchased my first refractor a few weeks ago: a Skywatcher esprit 80mm. But of course, I haven't had a clear night since I bought it!

 

[davenn]

Skywatcher esprit 80mm

this one ?

http://www.skywatcherusa.com/product/esprit-80mm-ed-triplet-apo-refractor/

But of course, I haven't had a clear night since I bought it!

haha yeah, that is pretty typical and every astronomer within a couple of 100 km's can blame you for the cloudy skies

Don't know if you read @sophiecentaur 's post #130, he has the 80mm Equinox
Dave

 

[davenn]

Can't win 'em all. It's not too bad here as there are no street lamps and the only pollution is from some garden lighting next door (she is security mad).

grrrr ... been there too in days gone by

My astrophotography efforts are put to shame by some club members who live close into London. The worse the conditions, the more nerdy you have to be.

yup, that's where you can use some of narrow band filters ... they give weird colours but still give awesome results in heavily light polluted areas
I haven't gone that path as yet. I just travel around an hour out of the city area to get to darker areas.

Some of your solar pictures are good justification for your spending, though.

cheers

BTW, what sort of solar energy rejection filter can you use with your 120mm? I thought there were limits to objective sizes for 'rear end' filtering.

For the Daystar Quark as shown in my photo above, it can handle up to 150mm objective before a ERF is needed
I bought the 120mm scope rather than the 102mm with the thought that I can always stop it down to ~ 100mm. This would still give a 40mm improvement over the Lunt 60mm scope and it would also kick the f-ratio up a bit to improve image sharpness over it's f8.3 @ 120mm

I have a shiny Baader filter for my 80mm objective but that is a poor man's solution to solar, I think.

The Baader filters are good white light filters and I will still use my one for sunspot imaging ( not that there are many of them lately ... solar minimum)Dave

 

[NFuller]

this one ?

http://www.skywatcherusa.com/product/esprit-80mm-ed-triplet-apo-refractor/

Yep, that's it.

Don't know if you read @sophiecentaur 's post #130, he has the 80mm Equinox

Yes. I don't know much about those scopes, but I'm sure they are of good quality. I believe it is a FPL53 doublet...

 

[davenn]

Yep, that's it.

sweet ! ... really nice looking scope and quite compact
What sort of mount do you have for it ?

Yes. I don't know much about those scopes, but I'm sure they are of good quality. I believe it is a FPL53 doublet...

I'm assuming, awaiting confirmation from @sophiecentaur , that it is this one ...
https://www.teleskop-express.de//sh...ox-80---80-500mm-Apo-with-aluminium-case.html

a good looking scope

 

[davenn]

The Sun in Ha 13 Apr 2018

Been off work all week with a not nice case of bronchitis, am feeling very unwell
but did decide to haul the gear out today and do some solar imaging
Reasonably quiet, 4 or 5 small filaments across lower part of disk, 2 groups of prominences on opposite limbs.
The new active region has moved further onto the disk and is showing an associated filament ...
The seeing conditions were better than yesterday
Lunt LS60THa, ZWO ASI1600MM and SharpCap capture software

Cheers
Dave

 

[sophiecentaur]

I'm assuming, awaiting confirmation from @sophiecentaur , that it is this one ...

Yes. That one looks like mine. It'svery nice. A great (some might say too blingy) finish and focuses well. The rotatable focuser could be better, though. A lot of manual filter changing and suchlike could perhaps make it come loose.

 

[NFuller]

What sort of mount do you have for it ?

I have a celestron cgx mount I use for this as well as another scope.

 

[davenn]

I have a celestron cgx mount I use for this as well as another scope.

nice mount

that now begs the question ... what is the other scope ?

 

[NFuller]

nice mount

Thanks, I've been happy with it so far.

that now begs the question ... what is the other scope ?

The other scope is a celestron EdgeHD 800. I use this one for smaller objects like planets and galaxies.

 

[davenn]

I have a celestron cgx mount I use for this as well as another scope.

Thanks, I've been happy with it so far.

the one you see in my posts #102 and #129 is the Skywatcher HEQ5 PRO, also a good solid mount :)

The other scope is a celestron EdgeHD 800.

Sweet !

My main scope is the Celestron CPC925, bought that at the beginning of 2012, it's a fork mount scope on an Al/Az mount

without going back through pages of posts, I can't remember if you have any sort of solar filter

I commented to Sophicentaur a few posts ago that the Baader filters are good white light filters for sunspots, and some other visible light surface features. It can be purchased as a roll or sheet of film
quite cheaply. I bought a roll of it, enough to make several filters for scopes and camera lenses etc.

eg ...
https://www.ozscopes.com.au/baader-astrosolar-safety-film-large-100cm-x-50cm.html
https://www.ozscopes.com.au/accessories/eyepieces/filters?p=3

the first link is the one I got ... will do many filters

dunno where you live, probably some where with sales closer to you
Dave

 

[NFuller]

without going back through pages of posts, I can't remember if you have any sort of solar filter

Currently, I don't, but I have been thinking about getting an Ha setup for my 80mm and a white light filter for the 8" from 1000 oaks optical. I've heard many good things about their products. Here are the links below.

http://thousandoaksoptical.com/shop/solar-filters/full-aperture-solarlite/
http://thousandoaksoptical.com/shop/h-alpha/h-alpha-9-angstrom-complete-system/

 

[davenn]

The Baader filters are good white light filters and I will still use my one for sunspot imaging

and a white light filter for the 8" from 1000 oaks optical. I've heard many good things about their products.

yup, the 1000 Oaks W/L filters are good, I have 2 of them one for the CPC925 and one for the 100-400mm Canon camera lenshadn't seen this system before ...
http://thousandoaksoptical.com/shop/h-alpha/h-alpha-9-angstrom-complete-system/

just be aware that at 0.9A you are not likely to see the filaments on the face of the disk ( at minimum only a hint of the very largest ones)
as you can see from their supplied images ... the surface features are very blurred
0.9A is quite a broadband bandwidth. for every 0.1A you drop in bandwidth, the features become sharper and sharper
so dropping from the 0.9A down to the 0.65 - 0.7A of my Lunt system lots more details appear.
Dropping to the 0.45 - 0.5A, of my Daystar Chromospheric filter, is even better for surface/disk face features

I would suggest you do some research on the different filters and spent the most your budget can afford ...
it will possibly save disappointment and having to pend a whole bunch more money later on

when buying expensive gear, I'm a firm believer in the saying "do it once, do it right"

you have spent good money on excellent scopes ... DON'T skimp on a lesser quality a Ha solar filter

hope that all makes sense ?

Dave

 

[NFuller]

just be aware that at 0.9A you are not likely to see the filaments on the face of the disk ( at minimum only a hint of the very largest ones)
as you can see from their supplied images ... the surface features are very blurred
0.9A is quite a broadband bandwidth. for every 0.1A you drop in bandwidth, the features become sharper and sharper
so dropping from the 0.9A down to the 65 - 0.7A of my Lunt system lots more details appear.
Dropping to the 0.45 - 0.5A, of my Daystar Chromospheric filter, is even better for surface/disk face features

Thanks for the advice. I just started looking at Ha solar filters so I haven't really decided what to go with. The daystar filters look very nice, but you definitely pay a premium on them... $10000 for 0.3A

 

[davenn]

Thanks for the advice. I just started looking at Ha solar filters so I haven't really decided what to go with. The daystar filters look very nice, but you definitely pay a premium on them... $10000 for 0.3A

Take your time, wouldn't want you to have any regrets
it took me 25+ years to finally be able to afford a Ha filter/scope, their prices have dropped considerably ( also their quality has probably improved in that time)
It was only last August (2017) that I finally lashed out on the Lunt LS60Tha ... AU$2599.
The Daystar Quark Chromosphere one came a month later at around AU$1600 (~US$1295)

My wish list for another filter, if I could afford it, a Calcium-K filter. It gives a very different view of the disk features

Photo credit: Guilherme Grassmann

he is one of the member s of the
Uk Solar Imaging & Observations. on facebook

a good group to see what people are up to with solar observing
Dave‎

 

[davenn]

The Sun in Ha 21 Apr 2018
Absolutely crap seeing conditions... even the "blue" parts of the sky between the cloud gaps had a high haze.
Nice new active region with spots and a nice prominence showing a large detached section
Lunt LS60THa, ASI 1600MM camera and Sharpcap capture software

Full Disk

AR2706

large detached prominence

Dave

 

[Zeke_D]

Thermal flows imaged with Baader Astrosolar 5.0