How far can you see ?

[Stevie816]

From my garden last night I could just about make out magnitude 9 objects with my 10" Meade ?

What I'm wondering is, Is this good or bad ?

I know there are many variables but how far back should I be able to go from a good site on a good day ?

Not sure if there is an answer but I would appreciate your thoughts

Steve

[pete_l]

There are formulas and tables, like this one.

But a lot of it depends on how <strike>imaginative</strike> experienced you are - and of course, the ever-present question of how much LP is in your sky

[Telrad]

There are formulas and tables, like this one.

That's a good link Pete, very useful. Cheers!

[John]

I've managed to see a magnitude 13 supernova with my 10" newtonian from my back garden earlier this year. It was in a galaxy that is around 65 million light years from us. The galaxy was in Ursa Major and well overhead when I observed it so well away from the lightglows from nearby Bristol and Newport. Thats the faintest I've been able to go.

[Cjg]

Andromeda M31 I think is the furthest - fortunate that a tree shields much of the street lamp that shines into our garden - so seen with my 102 frac and the 10" dob.

Chris

[Nova]

M57 mag 9 is about the best ive done with my 6" newt altough it can apparently goto 13

[michael.h.f.wilkinson]

A 10" should be able to go much deeper. I can get mag 10 stars with my 15x70 and 80mm triplet. Conditions must be good, of course.

With my C8, I have tracked SN2011fe down to mag 13.2, when it was low in the sky. LP was not too bad, and the sky was very transparent. I have also nabbed mag 13 galaxies (in a dark location). A lot of practice with averted vision helps a lot.

[Tim]

The title of the thread is the question I get asked the most by non-astronomers, "How far can you see then?"

I never know quite how to answer, because if you say "100's of millions of light years!" they just go blank.

With a sensitive camera on the MN190 I was picking up faint galaxies in the region of mag 17 IIRC. There is a particular region I imaged once that had a fov full of fuzzies and very few stars, but a problem with the camera meant I never finished the picture, but seeing all them faint fuzzies rolling out of my little observatory was quite inspiring!

Cheers

Tim

[Stevie816]

They are all very interesting answers

thanks guys

[Double Kick Drum]

My 5" refractor's limit is between mag 11.5 and 12 in semi-rural skies and in truly dark skies to between 13 and 13.5.

I should think a 10" can go an extra magnitude and a half (if my maths is correct!)

[Hypernova]

I managed 3c273 at magnitude 12.8 back at SGL6 in April with my 8" dobsonian, the skies were quite dark. Not bad at 2 billion light years

But usually I can get to mag 11.5 on a good night with it from my light polluted site in Crewe, magnitude 4.5 is the average limiting magnitude for the naked eye. Mag 9 sounds fairly poor for a 10" but I suppose with the moon in the sky and/or a bit of high cloud it would sound about right. It all depends on the sky conditions.