I tried to get some colour for M78 last night seeing as I never seem to get a chance at an Astrocamp. It's either just before dawn or just about to sink in the March time, so I am never at a dark site at the right time.
Apart from doing the Pleiades recently which is bright anyway, I haven't done much broadband for some time at home and have come to the conclusion that broadband is a complete waste of time now in Bromley. I couldn't even do 600sec luminance as the sensor was quite washed out. Even some of the 300sec results were also washed out. I know M78 is probably not a suitable target for LP location but I certainly expected better than I got last night. I am wondering whether it is due to the installation of LED lighting, as I don't recall having a problem to this degree previously.
Also had another strange experience last night. I could not shut the dome, it was getting stuck 3/4 of the way down. Could not fathom out what the problem was, but eventually realised that next door's fence was leaning over after Doris had done its worst, and was obstructing the dome, so had to close up the opposite way to how I normally do it and sort it out in the daylight. I have temporarily now put a wedge in between the walls of the obsy and the fence. Hopefully the neighbours will get it repaired this week.
Carole
M78 is very dim - you will find it all but impossible to get decent RGB data from a light polluted location. It is a challenging enough target even from where I am - it requires an above average night.
Are you using a light pollution filter? If so, which one? In the days of sodium street lighting it would certainly help but it wouldn't be a complete answer. Whether or not they are still helpful from an area lit with LED streetlights is an interesting question. It depends whether the main sky glow is caused by the new LED lighting or the existing sodium lights. I think only a spectral analysis would determine the answer to that - an interesting project :)
Mark
I was using my CCD camera, I must admit no LP filter on, but I don't remember the sky being as bad as this before. I think I probably suffer from both LED and Sodium as I don't think everywhere is converted yet. I was outside a few evenings ago and the whole sky looked visually red and I also don't remember ever seeing that before either, not with the naked eye.
I have a feeling things have just got worse where I live, things that I could see naked eye a few years ago are almost disappeared, like the Pleiades is really difficult to see now.
Carole
If the sky looked visually red then it sounds to me like sodium lighting is still the main problem and a light pollution filter will help. My guess is that it was just probably a "murkier than usual" night.
Mark
I'm afraid that is going to get worse - more people leads to more housing and more traffic, which leads to more pollution (both light as well as atmospheric - gasses and particulates) which in turn reflects the light back. That is killing our skies. I have a big problem with Tesco in Orpington (due south) - one has opened up near you in the last year or so hasn't it ? Does that coincide with the increase in LP you're experiencing?
I remember being able to see the Milky Way from Sidcup 'when I was a lad' but now Sevenoaks has roughly the equivalent sky.
Broadband is possible but you will need a lot of subs to increase the signal to noise ratio; either that or take pictures of stellar objects like Globulars and star clusters; of course there is also the 'nuclear' option of moving...
Robert
Unfortunately probably not in the part of Sevenoaks where we live, where the Sainsbury's retail park destroys our northern viewing, and due south is not an option due to the street lights. For some time I've been thinking about trying to make a crude spectrometer to try and identify the major wavelengths of the light pollution so as to choose the best light pollution filter (notwithstanding issues of colour balance).
Roy
I think it has got decidedly worse over the last few years. I can hardly see Pleiades now, and even the main asterisms are getting harder and harder to see.
I guess some of the brighter targets might still be doable, but don't want to keep repeating the same targets all the time.
I think I have to resign myself to narrowband only except at dark sites and even some of those are not doable in Bromley. For instance, some targets are just about doable in Ha, but not in Oiii or Sii, i.e. Pacman, Wizard which I have had to do at a dark site. Add to that all the lower Southern stuff I can't reach from home because of trees, its getting pretty depressing. Orion I can get most of it for some of the evening, but anything lower such as Sirius at best skims the top of trees.
Carole
Carole
I suspect a significant part of the problem comes from the new LED street lighting. It often seems to be run at a brighter level than the previous lighting, and the standards in use also seem to be rather less well controlled, at least along major roads. The ones along Crofton Road near the top of the hill by Orpington Station and in Locksbottom are prime bad examples.