Galaxy Hunting with 8" Failed... Help Please!

[PhotoGav]

So, I have a Celestron 8" EdgeHD on my HEQ5-Pro. I have failed in trying to photograph a galaxy tonight... Conditions were good, but I just struggled.

I aligned with EQMOD and Cartes Du Ciel, using a QHY5-II in the finder and my 60D on the scope. Everything seemed to be going well. Alignmaster got me to a good Polar Alignment. I slewed to Jupiter and it was near enough. I did a couple of videos of that, to process tomorrow, and generally I had a bit of a smile on my face.

Feeling quite confident that tonight was the night after so much waiting, I selected M81 in CdC, slewed to it and exposed a 60s sub at 6400ISO in APT. Stars, yes, any sign of a galaxy, no... I'm stuffed at that point as how do you go about finding your target when it's not even slightly in the field of view? Which way do you slew and how far? Quite...!

I then tried other galaxy targets M51, M101, M65... Each time stars, but no sign of a galaxy. I even shot some longer subs of 120s, but no sign of any swirly things.

I tried selecting and slewing to bright stars near my targets and syncing them in CdC, but this didn't seem to get me any closer to a galaxy.

Please help me.

I'm beginning to think that the 8" is just too much for little me to cope with and fear that I have spent my money unwisely........

[PhotoGav]

I fell asleep with one word going through my head....

"Astrotortilla"

Hopefully the next session will be more successful!

[RikM]

If I get 'in the general area' but not quite on the chip, I shoot 10sec subs through the guider using PHD, like an electronic finder. You can often see the smudge you're after and centre it that way. It does mean you need the guider and main scope well aligned, but it helps to have that alignment anyway.

[ronin]

Suspect the problem was: I slewed to Jupiter and it was near enough.

Near enough may not have been enough especially on a Celestron 8" EdgeHD, they are f/10 so a narrow field of view, the image is big so very dim.

I would also advise against going from a planet that was probably in the South to a galaxy that is in the North. Look at it like this if the goto was 1% out then as you have moved by close to 180 degrees across the sky there could be 1.8 degrees error and that is way over the field of view of the scope.

There is usually a precision option, the scope goes to a star close to what you want, you centre it accurately then it goes with a short hop to where you want. If there is no exact match on the HEQ5 Pro then do the same by going to Dubhe in the Plough, centre this accurately then ask the scope to goto M81. You could use Polaris as the star also as they are both close enough to M81.

If you are intending to image then near enough is not good enough, especially with a slow (f/10) long focal length scope.

[brantuk]

Hmmmm.... I think I would start the session with a bit of observing for half an hour to an hour first. Pop a diagonal and suitable eyepiece in and check the scope slews to targets accurately, paying close attention to object centering and finder centering. This would also confirm your polar alignment and star alignment. Pop in any corrections required for pointing accuracy.

Once you are satisfied all is well then take out the diag/ep and put the camera gear on. If you still don't see stuff on the screen then at least you'll know it's not the pointing that's causing your problem. With that potential problem eliminated you'll get a better start at diagnosis.

[PhotoGav]

Thank you for your comments Rik and ronin.

Yes, much to learn... As you say near enough is not actually near enough, especially when the other side of the sky...

I feel less frustrated now that I have slept and I can asign the session to 'taking a tiny step up that very steep learning curve'!

Bring on the next clear sky and a chance to get a little bit closer to those currently illusive galaxies - I know they're out there..........

[todd8137]

It would be great and easy if it all worked in one night it rarely. Goes right at that focal lenght any error s in any part of the kit will throw up these probs

Pat

[Luke]

I'm no expert but I would normally pick three aligment stars in a triangle around the target, and it would nail it every time. It costs an arm and a leg, but what about the 0.7 reducer for the Edge 8, to bring the focal length down to about 1.4m? I've also had fun using the reducer for lunar imaging.

[Russe]

+1 for AstroTortilla - you will have no more problems with finding stuff once that's up and running!

[PhotoGav]

Thanks Pat, Luke & Russe. Yes, another steep learning curve... Lots of problems that I am learning from, so not a wasted night, just astronomically frustrating. The focal reducer is on the shopping list, but I need to earn the money first as the bank balance has taken a massive drop since trying to take photographs in the dark! AT is on my hit list - hopefully will get the astro-laptop up to date with all the new files later today.

Clear skies, then at least we can make progress if not results!

[swag72]

A good point Gav about 'close enough' not being good enough. I find with the C9.25 that when I do a meridian flip I do need to resync to a nearby star to really nail the target. I also used to find that the backlash in the HEQ5 would often cause targets to be off and involve a little hunting about.

If when you slew to the target you keep the camera rolling on short exposures, you may see your target go past you so you can have an idea of where you need to go and hunt it down again

[Owmuchonomy]

Yep agree with all above.  My 9.25 SCT shows M81 and M82 beautifully.  SN is still visible too.  To ensure you get close to these elusive objects by GOTO or hopping make sure you do a star alignment the same side of the meridian as you wish to observe.  Last night I used Dubhe and Schedar or you could use Dubhe and Regulus for example.  I spent about an hour visual observing first (caught the occultation of Europa!).  Then I set up imaging.  I'm processing the Leo triplet lights right now!

Its a steep learning curve so don't be disheartened.

Regarding the focal reducer on a SCT be aware that for imaging it can cause anomalous flares off bright objects at the periphery so position your DSO carefully to avoid these.

[PhotoGav]

Thanks Sara & Owmuchonomy. This is all brilliant feedback that I look forward to putting into practice.

[Russe]

Astro laptop: I'm using a Dell mini 9 with 2GB RAM. You should be able to find a used one a bit cheaper - maybe on fleabay. You can't process your images with that though.

I'm running stellariumscope, Stellarium, APT, PHD, EQMOD, AstroTortilla and Comodo at the same time w/o problems.

[Russe]

Eg: http://bit.ly/1evPPan

I've put a 64GB SSD into mine as well and am running XP.

[cfpendock]

I agree that Astrotortilla is the way to go. 

Chris

[PorkyB]

There is no substitute for sticking in a nice widefield eyepiece and having a look around. I make mine parfocal with the camera by adding a home-made extension tube and a parfocal ring, so I can swap between the eyepiece and the camera without losing focus. After swapping the camera back in it's always a good idea to check the focus, but it is much easier to find a focus star in live view if the focus is already close to being right.

M81/82 is also really easy to find with an EQ mount without using goto. Line up on nu-UMa, start RA tracking and then just move up in Dec and they will appear in the eyepiece.

Last night I was imaging Markarian's Chain with my 130PDS on a non-goto EQ5 (ok, wider field of view than your Edge but there are some very nice low power widefield eyepieces that you could use). It was relatively easy to hop from Vindermatrix, through some of the brighter galaxies to get there. I managed it at the second attempt, so goto can help you but if it lets you down then you can certainly do without it.

[PhotoGav]

PorkyB - indeed, I should have just gone visual for a bit to suss things out. That's what I did the time before and did resolve goto inaccuracies. I guess I was caught up in trying to get it all to work from the laptop screen... Look forward to seeing the fruits of your labours posted once processed!

[PhotoGav]

Astro laptop: I'm using a Dell mini 9 with 2GB RAM. You should be able to find a used one a bit cheaper - maybe on fleabay. You can't process your images with that though.

I'm running stellariumscope, Stellarium, APT, PHD, EQMOD, AstroTortilla and Comodo at the same time w/o problems.

Wow - that's cheap! I currently use an old-ish IBM ThinkPad - it works perfectly with all the various apps open... It's the operator that doesn't work so well and needs upgrading...!

[PorkyB]

PorkyB ...Look forward to seeing the fruits of your labours posted once processed!

Oh go on then

http://stargazerslounge.com/topic/209477-galaxy-hunting-with-a-130pds/

[Astrosurf]

This thread's great as I have the same problems. I find my Telrad very helpful, but only for bright stars as I have poor night vision (crazy to take up this hobby then!) Plus the thing dews up easily and is bulky. I'm going to get a red dot finder as it should be easier for my poor old eyes - just need to find the best place to mount it. If you decide to use a red dot finder (or Telrad), it will need aligning up with your scope. Do that at a distant object in the daytime beforehand if you can. Or a very bright star.

Could someone post a safe link to AstroTortilla? I've had so much malware over the years, even with good ant-virus sw, I'm twtichy!

EDIT: it's ok, the link is on the tutorial!

[Russe]

http://sourceforge.net/p/astrotortilla/home/Home/

[Russe]

I suppose you could use AT to center your scope on an object and then remove the camera. But you'll [removed word] up your night vision every time you look at your comp...???

[PhotoGav]

SUCCESS!!!!

So, this is like one of Fox Talbot's prints - really the point is that it can be done, not the image itself!

After: setting-up, clouds rolling in, waiting, taking everything in, sky clearing as last item removed from garden, swearing, cursing, pondering, setting up again.... I used Astrotortilla to help bring the first alignment star in Alignmaster into the field of view of the scope and 60D and successfully Polar Align. GOTOs after that one use of AT were well within the camera FOV. I was quite excited at the idea of my first AT galaxy centering, but never needed to... I slewed to M81, exposed a sighter sub and there in the bottom right quadrant was a fuzzy. I skipped around the garden. I centred up and here it is in all it's very low res, 6400 ISO, one sub, unprocessed glory. Halleluliah!

Thank you all for your help, assistance, guidance and moral support. I now can't wait for a decent clear night and my first proper galaxy imaging session.

[Astrosurf]

Brilliant job! I can't wait to use the sw.