Second choice of target - M97

[Ant]

I bought myself a 28mm wide field camera lense - not expensive - but with the correct thread to connect to the H9. I thought that it would make some nice wide field shots... I have also got a male to male T adapter to connect the H9 directly to the filter wheel. Last night was supposed to be a test of the H9 and camera lens.

But after connecting the H9 to the filter wheel with the new adapter the other day - I couldn't remove it last night to attach the camera lens. So decided to go for M97 instead, I've never attempted M97 before.

Then I found that I'd made such a difference to the camera/filterwheel/focuser setup that I couldn't acheive focus! So had to have a rummage through the spare parts case to see what I had lying around.

Is it me or is M97 NOT the best target to image in Ha(7nm)..? Even with 10 minute subs, there's not a lot there! There is also a distinct lack of guide stars in the area as well. I managed to get a guide star, but I was using a 4 second exposure and it was still saying a low SNR... I think that's why the guiding was shot to peices...

The image attached is 5 x 10 minute subs. I lost 5 subs due to trailing - according to SAT24 a layer of high cloud came in, I couldn't see it visually, but I think it affected the guide star.

I've learn that I really need to do Dark Frames. Never needed them before with sub 300 second subs... but 600 seconds and up they are quite apparent (as you'll see).

So I'll have another process at this tonight, but I'll take Darks (at roughly the same temp) and Bias frames.

I'll also try for some OIII and Hb data the next night that I'm out. You neer know I might get more than 5 subs...

I do have a question though... PHD was working well. When PHD loses a guide star and then finds it again, does it return the guide star to it's original position or start guiding from where it found it?

Depending on the answer to the question above, I may still have some flexure in the system. You can see from the hot pixels the extent of the movement - that's around 2 hours, so I can live with that but I'd still like to sort it if I can.

The attached image will be reprocessed with some Darks and Bias. This image was processed last night at around 1am - it was very rushed as I should have been in bed!

The really annoying thing is that after trying - and I did really try to get the T adapter off using plumbers plyers and giving up... I was stood talkign to Jane in the kitchen and it just unscrewed - I wasn't even trying!!!

So I'll be going back to the original method of attaching the camera/filterwheel.

Cheers

Ant

[SteveL]

I do have a question though... PHD was working well. When PHD loses a guide star and then finds it again, does it return the guide star to it's original position or start guiding from where it found it?

PHD will guide on a star within the bounding box area. It starts with the one you selected. If there is a star within that box when it can start to see them again, I am pretty sure it will try to return that star to the middle of the box. It may or may not be the same star it started guiding on before it lost visual (depending on any polar alignment and tracking issues that would make the system drift whilst unguided).... it has no way of really knowing if its the same star or not, its just looking for a star.

I had PHD lock onto a plane that passed right through the guidebox, it got REALLY upset for a few frames.

[Ant]

The ISS went through one of my frames last night - that was amazing bright!

Here's another image, this time with 50xBIAS and 5x Darks.

This is an improvement, but still not great - I suppose I was hoping for more with 10m subs - but maybe I just need more of them.

Ant

[barkis]

A faint little blighter Ant, so I suspect it needs loads of subs.

There are three stars embedded in the Owl, and I can't see one.

Did you have a filter in there perhaps?

Apparently the light from M97 is emitted in the green spectral line, but it will take a wiser person than me to decide if that affects this Mono Image in any way.

Anyway, it's good enough to see something from you after the headaches you've had with guiding of late.

A bit more volcanic ash would keep the planes at bay at least.

Ron.

[Ant]

Cheers Ron, yes it was taken with a 7nm Ha filter. I do get the impression that m97 is stronger in the OIII line (which is on the green side) than the Ha ...

Ant

[Tim]

The 3 stars Ron mentions hardly show with the 7nm filter, even on very long subs they are faint.

The OIII will combine nicely with this Ant.