Can stars be light pollution?

[Jessun]

Imagine a fellow amateur astonomer doing a journey from his home in M31 to our planet to compare imaging tecniques. He would show us an image of our galaxy that he took halfway on his journey just using his DSLR on a tripod for a single shot and it shows our galaxy nicely framed in an absolute black void - not a single star outside of it or in front of it. Distant galaxies behind us he has edited out.

I'm sure he'd send shockwaves through the community here on earth. Not so much so because he is an alien species that just landed but because his images of the Universe are so crisp and star free.

So does anyone sometimes feel that stars are light pollution in images of galaxies or even features within our galaxy. It's almost like imaging one specific water molecule a mile down a garden hose!

Did anyone here experiment with editing stars out? Or do the stars still ''belong" in the picture merely to make them more familiar to us, and correspond to what we've ever seen so far?

I've had to explain to a lot of friends that the stars they see are not part of that distant galaxy in an image. They are merely massive dustbunnies!

/Jessun

[jimmyjamjoejoe]

I get this feeling to, like trying to see the trees through the forest.

[hemihaggis]

no , never , not on your nelly .

so does that mean the great hercules cluster is LP...?

i dont think many people on here think that the best thing to do with a beautiful binary star like alberio is to edit it out of the frame ,

the only kind of "stars" we should get rid of are on the telly ...like .... well i will let you make up your own minds on that one lol

[Si W]

no , never , not on your nelly . :icon_scratch:l

ROTFLMAO:D

[jimmyjamjoejoe]

I love looking at them, don't get me wrong, and there are plenty of targets in our own galaxy that are great viewing. I don't so much have a problem with the stars there for viewing, more for imaging. When i see a picture of a distant galaxy surrounded by local stars it ruins the sense of vastness, you don''t really grasp the immense void between here and there since you can't really relate a distance to the stars in the photo.

It's like trying to take a photo of a lion in the distance, the last thing you want is a chain link fence in the foreground ruining the illusion of it being in the wild.

[Shibby]

That's quite an interesting question actually. I don't mind the stars generally I think they add something. They're not artifacts - they're really there! However, the brighter ones do bloat a lot due to optical imperfections in our instruments and these can be a bit distracting, particularly for "local" nebulae where we look through the milky way, but not often for galaxies.

Having said that I like them, I do, like you Jessun, always have to explain what they are when showing images to family & friends. However, I like the way this makes people think about what they're looking at.

[Jessun]

jimmyjamjoejoe funny you should mention lions, I had the same idea in mind having some grass in the foreground to add depth to such an image, but again and again and again on every photo??

hemihaggis the Hercules cluster is magnificent enough on it's own without other stars down that narrow line of sight isn't it?

It's just a though folks!

/Jessun

[michael.h.f.wilkinson]

I have had problems finding certain objects (IC 342, NGC 147, Barnard's Galaxy) due to the rich star fields (extinction by dust in our galaxy is a more severe problem, I think). Some open clusters actually show up better in bins than the big scope because they stand out more.

I do not consider stars LP, however. If all objects were easy, wouldn't life be dull?

[661-pete]

The main nuisance is with comets, I think. I personally don't very much like those long exposure images with star trails, merely so the we can track on the comet, but I appreciate that options are limited. I know it's possible to process the stars and the comet separately and then re-combine, so that you get sharp stars and sharp comet in the same image, but I've never figured out the technique. So - in a sense - in a comet image at least - yes I regard stars as a sort of 'pollution'.

But not otherwise. If you take an image of a rich star field, let there be lots of stars in the final image! For example, M11 (the Wild Duck) wouldn't look 'right' if it weren't seen embedded in one of the richest areas of the MW. Likewise the Perseus double cluster.

[FraserClarke]

From a professional side -- very much so!

Seeing faint things (i.e. extrasolar planets) next to stars is mainly limited by the glare of star. For example, a planet like Jupiter is about 1 billion times fainter than the Sun. So, for every photon that comes from an extrasolar Jupiter, 999,999,999 photons come from the star! (and you thought that streetlights were bad ). If you want to see the planet, you have to filter out the light from the star.

An awful lot of professional astronomer effort is going into working out how to get rid of "light pollution" from stars Though I admit this is the first time I've heard it called light pollution...

[blinky]

I do find that some objects, my recent California Nebula being a good example, where by doing a minimum filter on the stars to reduce them, makes the image stand out much better.