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Rob63

Triangulum M33

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Thanks for all the reply's I am sure I will be able to get it eventually.

I was looking at around 11pm before the clouds started rolling in it would have been higher and further south if I had been out around 1am so I may try then.

Would a UHC filter help with galaxies?

Any recommendations for dark sky sites around Edinburgh?

As Mark has said, a UHC filter would not help for galaxies in general, but it does help to show NGC 604, a star forming region within the northern spiral arm of M33.

You need an excellent dark moonless and transparent night for that.  But with my 10" Dob at my club's dark site, tiny NGC 604 was not hard to see with the UHC filter. Definitely remove the filter to see the galaxy itself.

Regards, Ed.

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M33 is difficult to see, it really does need a dark sky or a good aperture. Not sure if binoculars are an advantage,

Aperture cannot increase surface brightness. That is impossible. All extended objects are as bright with the naked eye as they are through any telescope regardless of aperture.

The contrast between M33 and its sky background will therefore not improve with aperture. Only darker skies will help.

Aperture only increases total brightness enabling us to see a larger image at the same brightness. This is why it never helps with large faint fuzzies. They are already big, aperture offers no benefits on them. It can help to pick out detail in them, but not the object itself. Only the contrast available by your sky conditions can help with this.

Aperture may rule, but only when dark skies let it :)

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Aperture cannot increase surface brightness. That is impossible. All extended objects are as bright with the naked eye as they are through any telescope regardless of aperture.

The contrast between M33 and its sky background will therefore not improve with aperture. Only darker skies will help.

Aperture only increases total brightness enabling us to see a larger image at the same brightness. This is why it never helps with large faint fuzzies. They are already big, aperture offers no benefits on them. It can help to pick out detail in them, but not the object itself. Only the contrast available by your sky conditions can help with this.

Aperture may rule, but only when dark skies let it :)

Surely aperture can increase surface brightness? but it will also increase the surface brightness of any background so it can't increase contrast. I thought aperture will increase surface brightness if your magnification is below the gain in aperture, i.e magnification < aperture / pupil size so a 12 inch scope would be limited to about 50x before you are reducing the surface brightness.

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Surely aperture can increase surface brightness? but it will also increase the surface brightness of any background so it can't increase contrast. I thought aperture will increase surface brightness if your magnification is below the gain in aperture, i.e magnification < aperture / pupil size so a 12 inch scope would be limited to about 50x before you are reducing the surface brightness.

Here, have a read of this it explains it way better than I can :)

http://www.rocketmime.com/astronomy/Telescope/SurfaceBrightness.html

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I saw M33 last night from a fairly dark location - limiting magnitude was about 5.5 - but transparency wasn't great, and so neither was the contrast. All I could see was a large fuzzy patch, about 30' across.

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Since reading this thread, I've been looking at M33 each clear night with my 15x70s; essentially, it is an easy target when the conditions are clear enough to see the Milky Way in some detail, but not if the MW isn't clearly visible. I had a quick try tonight as well with my ED80 'frac at x24 - not only clearly visible (even visible in the 9x50 RACI), but some sense of the nucleus and slight structure. 

Clearly, as stated above, this is a classic situation where seeing conditions and transparency are the most important factor.

Chris

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I wouldn't even try to find it from London because the surface brightness is too low. You might see something on an exceptional night, but it wouldn't be much. My short tube refractor gave great views of it from the depths of Exmoor!

DD

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In that part of the sky I always tend to look at Andromeda, M31, first.  If M101 (from Mirach, just beyond M31) is visible then it is usually worthwhile looking out for M33 which is about the same distance on the opposite side of Mirach.  And, if you pause a while on Mirach itself you may be able to spot the Ghost of Mirach, NGC404, about 7 arc-minutes away, a dwarf lenticular galaxy which is about 10milion light years distant.

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Saw it for the first time last night. It was my first attempt at M33 and I found it in less than two minutes - more luck than judgment I can assure you. Was observing from a fairly dark site with good transparency - milky way easily visible. Seen with a 200p dob at x92 and x50, latter power showed it best.

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M33 can do one, as far as I'm concerned :) I'm in a fairly light polluted area and I've tried and tried and tried (over the 2 or 3 years I've been into this hobby) to see it, to no avail. I even tried again on Wednesday night. No luck. It's one of those objects that really makes me doubt that I'm looking in the right location for it.

I did, however, have a thought/idea yesterday that might help me be sure I'm looking in the right space. Setting circles? I've never used mine but surely if I figure out how to use them and they're calibrated correctly I can just slew to the correct RA/DEC values and then just keep looking through the eyepiece and hopefully see something.

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M33 is a good example of where the stated magnitude (M5.7) can lead to misleading expectations. M33 is the 4th-brightest galaxy in the sky as measured by total, integrated, brightness, but because of its relatively low actual surface brightness, it's extremely hard to see in light-polluted surroundings as the above reports show. 

If you do have dark skies and a relatively large aperture scope the galaxy can show a surprising amount of detail apparently. Here is a link to a Sky & Telescope article on the galaxy which includes a further link to a detailed guide on what this object has to offer:

http://www.skyandtelescope.com/observing/objects/deepsky/65168927.html

I'm going to spend some more time on M33 this autumn and see if I can spot any of these features, when the sky is sufficiently dark  :smiley:

John I found you can 'just' about see the NGC's within M33 in mag 6 skies with excellent transparency but it took mag 6.4 skies for me to actually feel confident that my eyes weren't playing tricks (this was with my old 12" f/5). :)

ps. Hope your still enjoying that EQ platform. ;)

Edited by Mike73

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