M101 and M51

[andyk74]

Hi all,

This is my first post on here, although I have read numerous topics previously for advice. I currently have a SW 150PDS mounted on a SW AZ-EQ6GT mount. I have an Altair Astro GPCAM mono and a Nikon D5200 SLR. I have been trying to obtain images of M101 and M51 using the SLR but have not had any luck. I polar align using EQMOD and perform alignment in EQMOD also, however, I am not entirely certain that M101 and/or M51 are in view. I took some quick 30 second images last night, but could see nothing that resembled them within the frame. I know they will be small but I was expecting to see some sign that they were in view.

My question is, would these be visible through the scope and an eyepiece so i can check visually first?

Any help would be greatly appreciated.

[Special K]

Visually, you will most likely see these, M101 being the more difficult; though it will depend on your local light pollution. If you are at a dark site then visually you should be cashing in!!  

[andyk74]

Thanks Special K, Its not overly dark here, especially at this time of the year, and LP, whilst there, is not usually too bad either. I was using a 17mm EP last night, would that be OK to see them? 

I have only been doing AP for about 6 months and although I have got some good images of Jupiter and the moon, have not had any real luck with DSO's.

 

[wimvb]

If you do a proper polar alignment followed by a 3 star alignment on the Synscan, you should get the targets in the cameras field of view, even if not centered. For first exposures, set a high ISO and try the longest exposure time that makes sense for your conditions.

GoTo works better if one of the alignment stars is near the target, in your case the handle of the big dipper. The synscan also has Pointing Accuracy Enhancement, and as a last option, you can first target a bright star near the target and use that to evaluate how far off the GoTo is.

 

Good luck

[andyk74]

Thanks for the info wimvb.

 

[Herzy]

M51 is small in the sky but M101 is not as small as you probably think. I can get hints of the spiral arms in my 30s exposures of M101, and M51 is blatantly obvious. I honestly think your goto alignment is off. 

Before you go to one of these targets you should move to the star Capella or Arcturus. They are both bright so you can check to see how good/bad your goto alignment is. If it's spot on then move to the galaxies and take many exposures. 

As long as your sure it's in the FOV you should get good results after stacking and processing. 

Hayden

[bruno]

Print a star map of the area you are trying to view/image from stellarium or C2C or just off the web & compare the stars with what you can see on your screen/eyepiece

[alacant]

First, focus on Arcturus, then sync on 2 nearby stars. In this case say Alioth and Alkaid. Nail them in the centre of your imaging scope with APT then hit sync in CDC. Now slew to M51. It should be dead centre. HTH.

[andyk74]

Thank you everyone for he advice.

I have tried the Goto test with brighter objects and all seems to be ok - aligned on Regulus and slewed to Jupiter in Stellarium and it was dead centre. Moved to M51/M101 and did another star align on Alkaid, moved to M51 and took a 30 second exposure but nothing visible. As Herzy said above, there should be evidence of them on the images....guess I will just have to keep on trying!

[alacant]

Make sure the telescope is 0º with RA and 90º with dec. I think it's called cone error. If not, always sync on the same side of the meridian. HTH.

[andyk74]

Thanks alacant, that is something else I need to check.