Magnitude of 10x50 binoculars?

[gazza63]

Hi all

Clear night last night 

Instead of setting up my scope, I sat on the patio with a couple of vodkas with the mrs, and stargazed with the binoculars.

I tried to see if i could see M51 (whirlpool galaxy), seeing as the moon dropped below the horizon and it was quite dark, I'd give it a go!

I pointed where it should be, I could see the star but not the galaxy. I believe it to be around 8 mag?

My question is:

what is the highest magnitude given good seeing conditions can i expect from 10x50's?

Also, am I governed by the quality of optics, 

[Daniel-K]

i have the same bins and have no issues picking out m51 from my garden VLM is about 6.2

[DeepThought]

It's not so much about magnitude as it is surface brightness as magnitude takes into account the size of an object as well as how bright it is.

Take the Andromeda galaxy as an example, it has a magnitude of -21.5 in the book but it's nowhere near as bright to our eyes as a star like Sirius which is just magnitude -1.46. The difference is that Andromeda is enormous so it earns a higher magnitude.

There are some lists on the Internet that show surface brightness for all the popular DSOs, these will give you a good idea what you can and cannot see with your bins. If I wasn't on my phone I'd dig you one out but they're easily found with Google.

[Astrobits]

It will depend on your sky conditions. Last night the moon set around 2:00am and M51 would only have been about 10 degrees high. If you were observing before that time the moonlight would play a part.

I have seen the Crab Nebula, similar mag to M51, using 30mm binoculars but the Crab was high and the sky very transparent.

Nigel

[gazza63]

It's not so much about magnitude as it is surface brightness as magnitude takes into account the size of an object as well as how bright it is.

Take the Andromeda galaxy as an example, it has a magnitude of -21.5 in the book but it's nowhere near as bright to our eyes as a star like Sirius which is just magnitude -1.46. The difference is that Andromeda is enormous so it earns a higher magnitude.

There are some lists on the Internet that show surface brightness for all the popular DSOs, these will give you a good idea what you can and cannot see with your bins. If I wasn't on my phone I'd dig you one out but they're easily found with Google.

Thanks, I'll take a look