The Admiral

That's good news, hope you don't have any hitches! But more importantly, I can't help noticing how clean and clear your desk is . Ian

Not at all, I'm perfectly aware of my and my equipment's limitations. It does rank as one of my better achievments though . And having been made aware of what my image contained, I was both surprised and pleased! But then I think the "No EQ" thread is a bit of a niche one, and doesn't have the broader appeal! I did post my image on the DSO imaging thread as well. Ian

Well Herzy, I don't know anything really about variable star monitoring, but I guess it will all come down to its magnitude as to whether it is accessible to amateurs. I can't help thinking that the brighter ones have already been studied in depth, so I'm not sure what can be added to our scientific understanding by amateurs with basic gear. Equally, I could be totally wrong! Ian

Thanks for all your work SA, this is all very fascinating. Just look at those point-like stars from the 2.5m Newtonian! But then, there's a world of difference between a 2.5m Newtonian and an 'umble 102mm . Still, I think I must have been very lucky with the seeing that night. A bit of digging around and I came across the attached paper by the American Association of Variable Star Observers, AASVO, which I guess you've already seen, which makes for interesting reading. I see that the magnitude varied between about 18.3 and 19.5. The outreach program was quite demanding of observing, I quote: "Such observations would be non-trivial to plan at a ground-based observatory; an adequate ephemeris would require at least two cycles be observed with good signal to noise, and a sufficient number of observations per cycle to adequately detail the light curve. For this star, that would require at least 60 days of coverage, with observations every 2-3 nights at least. For this reason, the AAVSO observer community was asked to provide coverage of M31-V1 for several months prior to the planned HST visit in December 2010 and January 2011." Still, they got 11 participating observers. So yes, it does seem that there is a role for us amateurs, but given our weather conditions and the multiple sessions needed using an Alt-Az mount, trying to get data on variables which have periods of days does look distinctly difficult. Mind you, if you've got enough aperture and a sensitive camera I guess it might be feasible. But then, folks with that sort of investment wouldn't dream of using an Alt-Az mount! Thanks again, Ian Hubbles Cepheid in M31.pdf

That's a lovely image Ken, a lovely star field with small tight stars. Thanks for the cropped version! Actually, on my PC screen it it's not so essential because I can see sufficient detail, but on my tablet it helps these tired old eyes. I think I prefer the un-cropped image for colour though. Ian

To be perfectly honest, I don't really take too much notice. I don't have a lot of leeway on the dovetail anyway, and I know roughly where the balance point is and aim to put it close to the alt axis. It's not as though you can release a clutch on a Nexstar and see exactly where the balance point is. To my mind, it's better to be slightly out of balance than exactly balanced, because then the load will be carried on just one or other part of the cog tooth, if you see what I mean, but so long as it's consistent I can't see that it matters which. Other views may differ! Ian

Hmm indeed! Ian

That's a nice image there Steve, that nebula really has substance (if that's not a contradiction in terms!). Ian

Thank you sir, you're too kind. I've gone back to the StarTools output TIFF, and I think I'd have to say the optical aberrations would probably limit the observation of V1, never mind its magnitude! Still, it's a thought. It would be interesting to know what magnitudes those globs were, just for reference, though. I've attached two TIFFs, the first a heavily cropped up-rezed image of the region in question, and one where I've just applied a heavy contrast enhancement using curves. Make of them what you will Ian ST v2 crop2 rezup annot.TIF ST v2 crop2 rezup contrast.TIF

Thanks for that very interesting reply SA, though I confess to liking my globulars resolvable (that sounds rude, I don't know why!). And as to V1, I think your brain is deceiving you! It would indeed be remarkable to see it, though when I've more time later today I will just check out the tiff and see what gives. Pointless may be, but leave no stone unturned! Ian

Nige, StarTools expressly doesn't want any colour correction performed by DSS. See p18 of the ST Manual. I think aligning channels is akin to colour balancing, so should be OFF. These 2 vastly different backgrounds reminds me of when I was trying to sort out the the channel balance parameters for my non-supported, by DSS, Fuji RAWs. Ian

I find my Nexstar to be nice and stable with very little shake, and I'm putting 6-7kg of refractor/camera on it. I think though it is important to use the spreader and tighten well, and I don't extend the legs more than about 30cm/1 ft. Ian

Welcome Jon, I'm glad that you've come over to the 'dark' side! It is true that clusters tend to be easier because you are not dealing with feint nebulosity and you can get away with a shorter total exposure, but there are many clusters and only one M31 . My advice would be to give it a go while you have the chance; it is big and fairly bright, so in that respect it is probably one of the easier galaxies. And of course, provided that you get your subs, then you can re-visit as your processing skills improve. After a while you may feel that you can do better, so the next time it comes around you can be fully prepared. Cheers, Ian

Better still Ken, well done! A little brighter, which brings out the nebulous bits somewhat better. Given that you've scaled it to 300dpi on A3, does that mean that it'll end up on your wall? Ian

Yes! Ian

Very nice Ken. I prefer the LR tweaked version, but then I'm a sucker for vibrant images! I like the very fine blue stars you've captured. If it was mine I think I would crop it down a bit so as to give the galaxy greater impact and allow the structure to be more easily seen. I think you've got ample detail to allow that. Ian

For one who can't do late nights, very welcome! I couldn't image last night, but M33 is on my list to do. I am looking forward to seeing what you get in 2 hours. I'm also keen to see what you can conjure up on a red emitting nebula. By the way, if memory serves me correctly, weren't you in Somerset not long ago, or have I got that totally wrong? Ian

I'm sure, and there are micro-pc's which run Windows which are available for a modest sum these days. I had thought about the possibility of attaching that to the mount. As to your new camera, it strikes me that you about to enter another league with your images! Ian

Thanks SA, but it was more trying to avoid messing about with laptops and all the wires rather than mono vs colour. That's what I like about dslr's, you have a single package that you attach to the scope and away you go. Ian

Nige, have you seen this thread re. DSS alignment? May be pertinent to your situation? I don't wish to rub salt into the wound, but interested to know if have you managed to get your camera back up and working? Ian

Thanks Ken, a full and useful summary. Ian

I think Ken we might have been at cross purposes. I was referring to my first thoughts on your original offering, but I see that you are likely to be correct, a bit of both, and your revised image does look better to my eye. I just wasn't sure how much was down to gradient and how much to nebulosity. I also think the dark patch near HIP17692 is genuine, subtle, but it's there, and so I agree it's important not to push the black point too hard. How do you find the noise levels with the ASI? It certainly seems to have taken the community by storm. I wish though that they could produce a self-contained unit, like a dslr, but with such a device as the ASI, and a processor loaded with firmware which will do the astrophotography essentials. Clearly, though, it'd need a cable for cooling. Ian

To be honest Ken, my first reaction was that if it had been my image, I'd have probably made the background darker. But then, on looking closer I reckoned that actually the top LH corner looked OK, but also came to the conclusion that the rest of was lightened due to nebulosity. The prospect of gradients hadn't entered my head. Gradients? Nebulosity? Your call! Your resulting image does look good though, but it would be a pity if you removed some of its character. Ian PS. Having looked here, you are probably right though! http://www.messier-objects.com/messier-45-pleiades/ PPS. But then, looking here I'm not so sure! http://dso-browser.com/picture/view/1033/deep_sky/pleiades/M/45/bright-nebula/by-reptux?0=&from=dso&dso_id=859

Thanks Nige, bit of a curate's egg that one! Can't help with you query, I've not used an astro cam. Ian