Tell me more ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free, no registration required.
up vote 4 down vote favorite

How clearly can the stars of the Pleiades cluster be seen through a 15x telescope (for example, FunScope)?

share|improve this question
2  
Keep in mind, a scope is not determined by its magnification, but by its aperture. In other words, when speaking of your Funscope, you don't say "a 200x scope" but you say "a 76mm scope". Magnification can be changed, and it's meaningless for the most part, although most beginners are pathologically fixated on it for some reason. In some cases you need small magnification, in other cases a large one, and so on. Whereas the aperture is much more important - it determines how much light your scope captures, and what are the finest details you can see. Large aperture = you can see more. – Florin Andrei Oct 7 '11 at 19:35
1  
The FunScope comes with an eyepiece that gives 15x magnification, not 150X, so I edited the question to reflect that. PS Florin, cheap scope manufacturers can bump up the magnification with an equally cheap, tiny eyepiece, and then can plaster a bigger number on the box than other scopes. (Bonus points for beginners not noticing the difference between 8 cm aperture and 150X MAGNIFICATION!!!! WOWEEE WOW WOW!!!!!!!) – Andrew Oct 11 '11 at 14:22
I've never heard of FunScope, but at first I thought it was some kind of public observatory (i.e. BIG!). Hehe – Arlen Beiler Oct 11 '11 at 19:35
But look at the Specs telescope.com/Telescopes/Dobsonian-Telescopes/Mini-Dobsonians/… It says its 152x – Neel Basu Oct 12 '11 at 17:42
"Highest useful magnification" is something only manufacturers and distributors believe in, usually 50x per inch of aperture. It is only achievable only under perfect seeing conditions with perfect optics. The FunScope is severely limited by a spherical mirror rather than parabolic and an extremely short focal ratio = very severe spherical aberration. I own a FunScope, and have never been able to use more than 20x with it. Orion's 100mm SkyScanner reflector and 80mm GoScope refractor are both far better telescopes for only a few dollars more. – Geoff Gaherty Oct 13 '11 at 12:56

3 Answers

up vote 6 down vote

At that high a magnification, you will only be able to see a tiny fraction of the Pleiades at a time. Binoculars would be better.

[EDIT: This statement applies to the original phrasing of the question, which listed 150 as its magnification, not 15.]

share|improve this answer
1  
+1 on this one. With maybe adding "much, much" in front of "better". The same goes for other larger objects like the coat hanger cluster. – xmjx Oct 7 '11 at 10:50
up vote 11 down vote

The Pleiades is an open star cluster, not a star: it consists of over a thousand stars. Since it is spread over quite a wide area of sky, it is best viewed with binoculars or a low power eyepiece in a telescope; 150x or 200x would show you only a few stars, not the whole cluster.

Actually the FunScope is an excellent telescope to view the Pleiades, but with its 20mm eyepiece (15x). 150x or 200x is far too much magnification to use with a small telescope like this. I own a FunScope and have had excellent views of the Pleiades and the Andromeda Galaxy with it.

share|improve this answer
2  
Can you see any nebulosity using a FunScope? – Larry OBrien Oct 7 '11 at 20:04
1  
I haven't, but then I've never seen the nebulosity in the Pleiades with any scope. My eyes are just not good for seeing faint nebulosity close to bright stars. – Geoff Gaherty Oct 8 '11 at 11:44
up vote 0 down vote

A 76 mm scope at 15x would be amazing. I often use my 15x70 binoculars for open clusters.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.