Telescopy from under orange murk

[VictordeHolland]

I've considered buying a telescope a few times now, but every time that there is a reasonably clear night I'm scared by the amount of light pollution in my neighbourhood. The city lights and in particular the lighting from greenhouses just makes it impossible to see any object (without assists) with Vmag bigger than 3.5 ish.

Attached a picture of Orion taken with my phone to demonstrate the light pollution (the orange glow on the horizon). Not much to see, apart from Sirius, Rigel, Betelgueze and Aldebaran and the 'belt' of Orion (Mintaka, Alnilam and Alnitak). And the view in Stellarium with Vmag set to approximately visibility with the naked eye and light polution.

[xilman]

Originally Posted by VictordeHolland

I've considered buying a telescope a few times now, but every time that there is a reasonably clear night I'm scared by the amount of light pollution in my neighbourhood. The city lights and in particular the lighting from greenhouses just makes it impossible to see any object (without assists) with Vmag bigger than 3.5 ish.

Attached a picture of Orion taken with my phone to demonstrate the light pollution (the orange glow on the horizon). Not much to see, apart from Sirius, Rigel, Betelgueze and Aldebaran and the 'belt' of Orion (Mintaka, Alnilam and Alnitak). And the view in Stellarium with Vmag set to approximately visibility with the naked eye and light polution.

Looks rather like what Tom sees. He has taken some good images from his site. See my M45 and M33 series of posts for examples.

I can see somewhat fainter from where I live, perhaps to V=5.0 -- 5.5, but (a) I've had a lot of practice (most people can see at least one magnitude fainter after enough practice) and (b) I caught measles when a small child which left me unusually photosensitive --- this has both advantages and disadvantages.

[Nick]

Originally Posted by VictordeHolland

I've considered buying a telescope a few times now, but every time that there is a reasonably clear night I'm scared by the amount of light pollution in my neighbourhood. The city lights and in particular the lighting from greenhouses just makes it impossible to see any object (without assists) with Vmag bigger than 3.5 ish.

In the UK, there are places with relatively little light pollution - we found Exmoor to be good, for example.
Here in the Netherlands, I would try the nature areas on the Waddeneilanden.

[xilman]

Originally Posted by Nick

In the UK, there are places with relatively little light pollution - we found Exmoor to be good, for example.
Here in the Netherlands, I would try the nature areas on the Waddeneilanden.

To a large extent the amount of irritation caused by light pollution is heavily dependent on what kind of astronomy you want to do. Visual observation of faint galaxies and other diffuse objects absolutely requires dark skies. For visual observations of planets, double stars and clusters having steady skies is rather more important because there are usually plenty of photons and what you require is resolution. Variable star observation (my speciality) falls somewhere in between. Dark skies help contrast but so do high magnifications, which require close-in comparison stars, well-driven good optics and at least average seeing.

If you're doing imaging, things change. Scientific discoveries have been made from central London --- by observing in the near-IR where the atmosphere is transparent and light pollution minimal. In the optical the advice is to take multiple non-saturated images then stack them to increase dynamic range and SNR. You'll pick up stuff you are never likely to see visually, such as the reflection nebula in the Pleiades and the colours of H-II regions within a few tens of megaparsecs of us.

Advice that has been given to astronomers for over a century: get a usable telescope and use it because an unused telescope is a waste of money and storage space. A modern version is that driving for two hours each way to a good site is a mugs game because you just won't do it often enough. Use those four hours doing observations from home instead.

[Uncwilly]

If you are dealing with sodium vapour lamp light, there are filters that should help. Some are good for visual observation and some narrow band filters are good for composite colour astro-photography. Hɑ, OIII (oxygen 3), are 2 common ones for red and green respectively. I have seen photos using narrow filters that are quite good from polluted areas. The new white LED street lights are not good. IDA is working against light pollution in general.

[xilman]

Originally Posted by Uncwilly

If you are dealing with sodium vapour lamp light, there are filters that should help. Some are good for visual observation and some narrow band filters are good for composite colour astro-photography. Hɑ, OIII (oxygen 3), are 2 common ones for red and green respectively. I have seen photos using narrow filters that are quite good from polluted areas. The new white LED street lights are not good. IDA is working against light pollution in general.

Good point. If you are doing photometry seriously a set of BVR filters is a wise investment.