What can I expect from my 6"?

[David L]

As the title suggests, really...

I have recently purchased a second hand entry level 6" Newtonian on an equatorial mount with a couple of lenses.

I have experience in star gazing with binocs, I know the constellations and very famous DSO's (Andromeda Spiral, Orion Nebula, Pleiades) reasonably well.

But this is my first venture with a scope, I am still having trouble lining up the finder scope, but hopefully, with patience I should get that sorted soon. But I have managed to have a nosey at the moon a couple of nights ago, along with Jupiter.

But, what else can I expect to see from my scope's capabilities reasonably?.. I am not deluding myself that I will be able to spot the Sombrero galaxy or the Horsehead Nebula, they are way out of reach. But will I be able to catch a glimpse of the spiral galaxies in Ursa Major, the whirlpool galaxy, Ring nebula? Or am I being too optimistic?

I live between Sheffield and Chesterfield, which you might think would be a bit of a downer (it is - but for other reasons...) But it is fairly dark as I am surrounded by countryside on all sides and there are no street lights to the rear or side of the house...

Any advice massively appreciated

[Earl]

First of all, scopes are not equal, which scope is it do you know? and what are its specifications?

[sixela]

I am not deluding myself that I will be able to spot the Sombrero galaxy

Well, that's actually doable, if you ask me. The deepsky visibility calculators I use are all saying that it should still stick out like a sore thumb, at least from even a relatively dark site (it is very low on the horizon, though). You'll need quite a bit of magnification to see the dark lane, but the surface brightness is't that low, so even that should work.

or the Horsehead Nebula,

That's actually not impossible, but you'd need a H-beta filter and very, very, very dark skies.

But will I be able to catch a glimpse of the spiral galaxies in Ursa Major, the whirlpool galaxy, Ring nebula?

Yes to all. Certainly if your skies are dark enough, and for some objects even in suburban skies. M101 might be troublesome, but I don't expect things like M81 and M82 will be. M51 will be easy unless your skies aren't dark at all (but do wait until the right season to assess how good it looks) and M57 will, with enough power, be completely obvious even from fairly light polluted skies.

People generally underestimate what a 6" scope can show you, unless it's a very expensive APO refractor. I showed someone who was using a 150mm f/5 Newt for photography what he could expect visually from a dark site, and he was astounded at all the objects I showed to him just in Canes Venatici. Not M51, but things like the fine NGC4490/4485 pair (the "Cocoon Galaxy" and companion).

[spaceboy]

Well, that's actually doable, if you ask me. The deepsky visibility calculators I use are all saying that it should still stick out like a sore thumb,

Hi Sixela

May I ask what this calculator is ? Would come in handy as half the stuff I'm looking for isn't there. Certainly save me some observing time

SPACEBOY

[pvaz]

With reasonably dark skies you should be able to catch all DSOs on Messier's list. A bigger scope would allow you to resolve more individual stars in globulars or see the spiral structure on M51. Some of this will only be detected but others, like the Orion nebula or ring nebula, will show a lot of details. I saw the ring and orion on a 90mm and they looked fine.

BTW the sombrero is doable with 6", but I'm afraid the horsehead needs around 14" , or so I read.

[Moonshane]

The best test is to have a go! What can be seen with what scope depends on so many different factors but it's a good aperture and I understand the stuff of dreams of amateurs only a few years ago. there are literally hundreds of targets to see well in your scope.

if you don't have it then I'd recommend this book Illustrated Guide to Astronomical Wonders: From Novice to Master Observer DIY Science: Amazon.co.uk: Robert Thompson, Barbara Fritchman, Thompson: Books which gives excellent maps and guidance on locating targets but also in most cases a photo giving an idea of what the object looks like. They also give descriptions of how it looked in a 10" scope at various mags. Different from yours I know but it helps get an idea of what to expect. In my view this will be one of the best £16 purchases any astronomer will make.

good luck.

[sixela]

May I ask what this calculator is ? Would come in handy as half the stuff I'm looking for isn't there. Certainly save me some observing time

There are several ones. The one I like to use is:

Martin Mater's Astronomy Page - Deepsky Visibility Indicator

If the "contrast threshold" goes over -0.3 you can expect the object to be (barely) visible. If it goes over 0 you can expect the object to be visibly fairly simply.

[James4]

Hey David,

I had The Celestron 150 Omni XLT - a 6" Newtonian on CG4 mount. I was blown away by the views of Saturn and its imaging capabilities. I actually have an Astro-slide show on local TV here in Canada mainly shot with my 6" Newt and a 4" Refractor (simple achromat). I hate to admit it but I'm sure my 6" newt outperformed my 5" Refractor on many objects. I found using a Red Dot finder way easier than using a finder scope. The scope has such a wide field (mine was 750mm focal length f/5) that I could just point close to where I thought the Whirlpool Galaxy was, then shoot a few 1 minute exposures just running on the add-on RA motor and I was able to pull down some nice deep sky images with it. M81/M82 should be great - The Horsehead not visually, but yes to imaging it. I hated to part with my 6" Newt but need the cash to fund my 8" SCT. Enjoy your scope! p.s. here was a Jupter shot with my 6" Newt: Jupiter / CelestronImages.com - astrophotography with optics from Celestron Telescopes.

[bish]

My SW explorer 150p kept me busy for a couple of years observing mainly from a balcony with restricted view and terrible light pollution. Jupiter/Saturn/moon have been incredible with good seeing. M4, M104, M33, M101 a real struggle. M51, M81, M82, M27 and M57 all easy targets (as examples). If you can make it to a really dark site then there's a whole load of more possibilities (eg veil nabula)

[brantuk]

Hi David - what trouble exactly is it that you are having with the finder? One of the things a lot of newbies do is to try and align it with the main tube at night on a star. This is quite difficult and much easier to do in the daylight using a distant target like a church spire or a pylon tip. The further away the better - at least 1.5 to 2 miles would be fine. You can then refine it at night using higher power ep's once you have an object in both the finder and the main scope.

[David L]

Thanks for the advice everyone, I feel a bit more optimistic now...

The finder just needs to be aligned when the temperature goes up a bit, I tried to align outside the other day, but it's like trying to perform micro surgery with boxing gloves on.

Cheers

David

[brantuk]

Lol - fingerless glove might help there - specially the ones with the pull over finger mitten attachments.

[rawhead]

if you don't have it then I'd recommend this book Illustrated Guide to Astronomical Wonders: From Novice to Master Observer DIY Science: Amazon.co.uk: Robert Thompson, Barbara Fritchman, Thompson: Books which gives excellent maps and guidance on locating targets but also in most cases a photo giving an idea of what the object looks like. They also give descriptions of how it looked in a 10" scope at various mags. Different from yours I know but it helps get an idea of what to expect. In my view this will be one of the best £16 purchases any astronomer will make.

good luck.

I'll second the recommendation on that book purchase...

[DarkerSky]

I've seen the Sombrero with a 6" scope from a dark sky site, actually fairly easily. Even at low power with a 25mm EP I saw it as a slender ridge of light with a brighter central bulge

[spaceboy]

There are several ones. The one I like to use is:

Martin Mater's Astronomy Page - Deepsky Visibility Indicator

If the "contrast threshold" goes over -0.3 you can expect the object to be (barely) visible. If it goes over 0 you can expect the object to be visibly fairly simply.

Thanks

[ollypenrice]

I origniate from your neck of the woods. From a dark site in the Peak you might get the Sombrero but I think you are bit too far north, really.

Olly

[sixela]

Ah yes - forgot that M104 is very low from a site that is too much to the North.

[DarkerSky]

I origniate from your neck of the woods. From a dark site in the Peak you might get the Sombrero but I think you are bit too far north, really.

Olly

Depends on your southern horizon. I had in it on the North Wales coast with about 14 degrees to spare