Observing M45, The Pleiades

[Klesk14]

I tried observing the Pleiades for the first time the other night however I wasn't able to see the whole cluster.

Either I wasn't pointed directly at it, or you need a wider angel eye piece? I was approximately at 120x and didn't see anymore than one or 2 stars.

I'm just a little stuck and not sure of the question I'm looking to ask lol... But is this cluster easily observable?

[Pete Presland]

your better off with binoculars for this one

[JimStan]

Many "deep sky objects" are actually bigger than one might expect, and are better viewed with a low power eyepiece. Something like 50X will reveal a lot more of the sky than you might expect. Don't get caught up in the "600 power telescope" charade that so many advertising agents foist on the public to get them to buy their telescopes.

The real need is to collect more light so that you can actually SEE some of these large, but dim objects.

Try that 31mm eyepiece on your scope, without the barlow, and report back to us as to what you see !

Good luck ! Jim S.

[nightfisher]

decent bins or a widefield scope with a low power ep like a 32mm

[ollypenrice]

This was in your C11? It has an almighty focal length so you will need something seriously widefield like a Nagler 31 to open up the view, but even that won't show the whole cluster. I can just about fit the main asterism into a 26 Nagler in our TEC with a focal length a bit more than a third of yours (980mm.)

Olly

[ronin]

The pleiades are around a degree across so you would need a field of view a bit bigger, say 1.5 or 2 degrees,

With a plossl this means a magnification of 35x or just 25x.

So a long focal length eyepiece and preferably one with a wide field of view to start with.

A "normal" SWAN has 68 degree field so with one of them it means 45x for 1.5 deg or 35x for about 2 degrees.

Since the pleiades are much the same size as the Orion nebula you could use the same eyepiece for seeing all of both in one field.

[Klesk14]

Ok thanks with the great responses.

I'll try it again for sure but I'm still not done my eye piece collection, but slowly and surely I'll have a wider range of magnifications for these larger objects.

[Stu]

If I try this, in the mak (4000mm f/l), even with a 41mm panoptic I get a 0.7 degree field of view, and around x 97 mag. This only shows the central couple of stars. I suspect your scope will be similarly difficult to get a wide enough fov.

I use my refractor with 690 focal length and either 22mm or 31mm nagler and that gives either a 2.6 or 3.6 degree field and frames it beautifully. I like to be able to see the whole asterism with some sky around it so I can appreciate it better.

As also said, binoculars show it very well

Cheers

Stu

[glowjet]

This is just one of the advantages of being able to afford an Ethos or the less expensive Explore Scientific, with the 100 deg field of view, my letter is already on its way to Father Christmas

[BazMark]

There must be better views to be had from bigger aperture scopes but the best view I ever had of the pleiades was from my SW114pm that I used to own. Due to it's short FL, at 50x the whole mass of stars fit easily in the FOV and I could count around 50 stars if memory serves. It was spectacular. In some ways I wish I still had it as I can't get the FOV needed in my Mak

[Klesk14]

I'll have to pick up an Ethos EP eventually too. However, the 13mm will still give me some moderate to high magnification.

[Crunchard]

In my 250PX, with my 32mm Panaview I get most of it in.

So I can see how it would be a struggle.

[Stu]

In this instance, with the OP's scope, even a 21 mm ethos makes no real impact because of the long focal length of the scope. It would only give a 0.75 degree fov. A 41mm panoptic would get to just under a degree ie better but not enough.

Looking at an 8" f5 scope you would have more joy. Anything above a 22mm nagler or equivalent looks like it would fit it in. 31mm nag would be great.

At the end of the day scopes like the c11 and my mak are designed for high mag, high contrast views of planets, lunar and smaller dso's so are always going to struggle with objects over a degree.

Stu

[cantab]

Are focal reducers any use for visual for observing things like this, or are they strictly an imager's tool?

[Stu]

In theory they are very useful visually but you can run into issues of not having enough focus range. I have a 0.5 reducer around somewhere and have never been able to get focus with it. Sure it's possible though

Stu

[John]

I think the reality is that a scope with a focal length of 2,800 mm is not going to be optimum for extended objects. I get my best views of the The Pleiades and M31 using my 15x70 binoculars to be honest.

[Tinker1947]

The other night looking for star's with a full moon was like looking for a needle in haystack, some were visible but not many from where i live..couple of weeks back i took a peek with a 10" Skywatcher P and 28mm 2" epc, they all seems to be there.

[ismangil]

I think the reality is that a scope with a focal length of 2,800 mm is not going to be optimum for extended objects. I get my best views of the The Pleiades and M31 using my 15x70 binoculars to be honest.

Indeed, please reserve open clusters like Pleiades for us bins people :-)

Long focal length people is better used for planets and the moon...

-- Perry Ismangil

[rwilkey]

Your SCT is an f/10, 2800mm, that's a long f/ratio and not really a wide-field scope, and using your Ax LX 31mm you will only get a true field of 0.732 degrees, not enough to fit in the whole cluster. Comfortable exit pupil though at 2.49mm. Faster scopes are better at larger DSO's like this one.