what's goin on?

[estwing]

got myself a 12.5" solid tube dob on saturday...set up,stars came out...so did the moon and i couldn't find much in the way of dso's. how much moon kills dso hunting? because i was a little dissapointed to say the least....

[rory]

alot.

[estwing]

alot of moon, over half? or any moon? at what percentage should i not roll out the lightbucket?

[Double Kick Drum]

alot of moon, over half? or any moon? at what percentage should i not roll out the lightbucket?

I find that once you are at a five day old Moon it starts to impair viewing. A half Moon has quite a big impact and by the time you are at full Moon, forget it unless you want to look at brighter objects.

This month's waning half Moon should allow some evening viewing as it will be low in the sky and will rise quite late. So, only twelve or thirteen days until we can all go out to play again.

Happy hunting!

[rory]

if its a clear sky id take out the 12"dob regardless of moon status. bet you'll have some great views with it.

[estwing]

suppose i was expecting too much..moon was good at 381x!!tho!

[rory]

suppose i was expecting too much..moon was good at 381x!!tho!

x381 ! blimey, i bet it was.

here's damo's report, that'll cheer you up. another 12 inch dobby jobby .

http://stargazerslounge.com/observing-reports/182393-22-galaxies-supernova.html

[swamp thing]

Near the full moon I would get busy making yourself a dew shield and light shroud, that big lump of a scope is gonna need em.

Extraneous light is a problem for truss tube scopes.

My 16" LB Secondary was a dew magnet too.

Have fun:)

Regards Steve

[estwing]

it's a solid tube steve...dew shield?, light shourd.. any suggestions?

[perrin6]

Bright moon for me means double star viewing only, oh and moon viewing of course.

[swamp thing]

it's a solid tube steve...dew shield?, light shourd.. any suggestions?

Oh!

sorry buddy gotta learn to read properly:D

You won't be needing a shroud then. A dew shield would be good though.

Most make em from camper mats.

Regards Steve

[John]

You can find DSO's with some moonlight in the sky if you know where they are. They look very far from their best though - pale shadows of their appearance under a dark sky, so generally I look for something else on a moonlit night.

I did managed to find M95 last night but not to observe the galaxy - I wanted to check the status of the supernova in it, which is a point source, so was just visible to my 10" newtonian, even though it was magnitude 13.5 I believe. The galaxy itself was a barely visible hazy patch but it's a lot nicer in a dark sky.

[estwing]

i was using 40mm possol...which should be ok for galaxy huntin?

[swamp thing]

A 40mm plossl may have too big an exit pupil with your Dob. You maybe better off with a 32mm.

exit pupil

The smallest cross-section through the beam of light from an eyepiece through which all of the light from the eyepiece passes. The observer's eye should be at the exit pupil to see the full and brightest field of view. The diameter of the exit pupil is the focal length of the eyepiece divided by the focal ratio of the telescope. Thus an 18-mm eyepiece will have an exit pupil of 3 mm on an f/6 telescope. If the exit pupil is larger than the diameter of the dark-adapted eye (about 7 mm on average), some light will not enter the eye and will be wasted.

HTH

Regards Steve

[John]

As well as the over-large exit pupil issue that swamp thing (Steve) highlights above, a little more magnification can have the effect of darkening the background sky, making deep sky objects a little easier to spot.

I'd definitely prefer a 30mm / 32mm over a 40mm in an F/5 or faster scope.

[acey]

how much moon kills dso hunting? because i was a little dissapointed to say the least....

I try to do all my DSO viewing with the moon below the horizon. Even a very thin crescent low on the horizon is a big light source at a dark site, and will compromise your dark adaptation as well as the sky itself. It's certainly possible to see DSOs when the moon is present, but if the moon is large and high it's like trying to see them in twilight - not really worth the effort if you have an opportunity to view at another time in better conditions. If I arrive at my dark site before moonset I try to begin with star clusters, planetary nebulae or very bright galaxies, concentrating on the side of sky that is opposite the moon.

[Double Kick Drum]

i was using 40mm possol...which should be ok for galaxy huntin?

Agree with the others about using a 40mm EP.

The only caveat to that would be that they do come in useful as a main scope finder or for very wide views (Pleiades etc.)

Happy hunting!

[estwing]

also have the 26mm but will look out for a 30mm sw or uwv on the cheap as have already spent £400 this week! thanks for the advise on dso hunting, chin's up and so are my eye's...

[Moonshane]

the 26mm will be a lot better. when the moon's out, look at the moon! aperture can make a big difference to the views even with such a bright object.

also planets and brighter doubles are relatively unaffected.

worry not, your scope will start performing when the moon disappears again.

[Earl]

When the Moon is out to play, play with the moon

[estwing]

goin from 63mm to 318mm is a big jump in app, so sorry to seem like i'm a little lost...

[acey]

goin from 63mm to 318mm is a big jump in app, so sorry to seem like i'm a little lost...

Use the 63mm as a finder for the 318mm then you won't get lost!

[swamp thing]

also have the 26mm but will look out for a 30mm sw or uwv on the cheap as have already spent £400 this week!

If you need some more cash. You ought to sell some more hammers.

Ps. those weight forward ones are rubbish

[estwing]

but there brick-hammers are lush!

[swamp thing]

but there brick-hammers are lush!

Tell me about it. Their club hammers are really sweet too.

it's just those weight forward things.