Magnitude with 15x70 bins

[Dunkster]

Evening,

Had a good session last night and was cross-referencing stars with SkySafari 3 in the Pleiades for a while.

A couple of the fainter stars I was seeing are in the region of magnitude +8.5 - 9.0 ... given LP, how good or bad is that? (bins in sig)

Just wanted to get an idea of how good/bad my LP is

[Merlin66]

Unfortunately it sounds like the LP is pretty bad....I would have expected, under good skies, to see down to at least 9.5 and maybe below......

[Dunkster]

OK thanks

I'll try aiming for something a little more overhead the next time we have clear skies and see what I can see there!

[iamjulian]

70mm binoculars would be 10 times the aperture of your eye (assuming you are young 'ish and have a 7mm exit pupil), which equates to 100 times increase in light grasp. Each 5 magnitudes represents 100 times the amount of light. So if you can see mag 5 with your naked eye, you should be able to see about mag 10 through your binoculars.

If you are seeing mag 9, then you can probably see about mag 4 with your naked eye? I have no idea where that ranks on a light pollution scale. It's not city centre terrible, but it isn't great either. Moderate suburban light pollution perhaps?

[Dunkster]

Thanks - never thought it was going to be great, but it's good to put a finger more or less on it.

I'll try again with the bins another night and see what I can see. My garden faces east into the LP unfortunately, the house blocking the view west but also the lights on our street.

The need less light pollution map puts me at about 4.3-ish (Bortle=8).

I'm pretty much on the edge of the big orange blob, so I should be able to find some nearby better sites