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nunciusaustralis
member
Reged: 09/25/09
Posts: 95
Loc: Rio de janeiro, Brazil
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I often observe from my family house at Armação dos buzios . Is a beach resort on north of Rio de Janeiro state. Suburban conditions. With a celestron refractor 70mm and a 15X80 bino my limit mag have been around 8.0 or 8.2.
do some one know if this is pretty much what u can squeeze from such equipment or on a darker place i will be able to see more dim stuff. And so wich will be the limit on a darker sky? 
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Nuncius Australis
70mm celestron EQ
9x50 finderscope
15X80mm binocular
20mm e 10mm k eye pieces
2xomni barlow
www.nunciusaustralis.blogspot.com
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tatarjj
Pooh-Bah
Reged: 04/20/04
Posts: 1134
Loc: Austin, TX
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I'm not sure what the limit is for that aperture, but I do know for a FACT that you should be able to see fainter stars than that. So take that trip out to darker skies whenever you can. In fact, for the most part, sky darkness is even more important than aperture when it comes to what you see through the scope.
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John T.
Austin, TX
25" f/4.2 Dob
18" Obsession #701
4" Stellar Vue Achromat
8X56 Binos
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nunciusaustralis
member
Reged: 09/25/09
Posts: 95
Loc: Rio de janeiro, Brazil
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I understand that a can see stars dimmer than 8.2 (always do). But the dimmer deep sky object i see is around this. Theres de question of the surface brightness and i think that on non-stellar source maybe the maximum i can survive is around 8 maybe 9.0 mag.
Thanks .
All information welcomed. 
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Nuncius Australis
70mm celestron EQ
9x50 finderscope
15X80mm binocular
20mm e 10mm k eye pieces
2xomni barlow
www.nunciusaustralis.blogspot.com
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Dain
Carpal Tunnel
Reged: 03/24/05
Posts: 1596
Loc: N.Y. Adirondack Mnts. NGC 4565...
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I would imagine in some dark skies you could probably push that 70mm right to about mag. 11.5-maybe 12 on an extremely good night. In that case, with just a 70mm scope, you can go pretty deep and have quite alot of fun for a long time. But let me add, seeing that deep will take some experience at the eyepiece for a non-experienced observer.
Clear Skies to All!
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Best,
Dain
Adirondack Mountains (my true dark sky site)
@ Cedar River Flow
Local Site
Clear Skies?
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Tony Flanders
Post Laureate
Reged: 05/18/06
Posts: 3468
Loc: Cambridge, MA, USA
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Quote:
I often observe from my family house at Armação dos buzios . Is a beach resort on north of Rio de Janeiro state. Suburban conditions. With a celestron refractor 70mm and a 15X80 bino my limit mag have been around 8.0 or 8.2.
do some one know if this is pretty much what u can squeeze from such equipment or on a darker place i will be able to see more dim stuff. And so wich will be the limit on a darker sky?
With practice, you should be able to see considerably fainter DSOs than that with your 70-mm refractor even in suburban conditions. And in darker skies, most mag-10.0 DSOs should be visible, if not easy.
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Tony Flanders
First and foremost observing love: naked eye.
Second, binoculars.
Last but not least, telescopes.
And I sometimes dabble with cameras.
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Achernar
Postmaster
Reged: 02/25/06
Posts: 5025
Loc: Mobile, Alabama, USA
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From a dark site, you should be able to see all or most of the Messier objects with a 70mm refractor. Some will be mere smudges or smears of light, but they'll be visible, along with other NGC and even IC objects. Messier himself had a telescope of about the same aperture, but with greatly inferior optics compared to what is available today. He however didn't have the kind of light pollution that extends up to 200 miles, or 320 kilometers in ever direction from the center of major cities either to contend with. You've been experiencing light pollution's effect on faint objects. From a dark area, you should be able to see 10th and 11th magnitude objects. With a 10-inch, I've managed to see galaxies as faint as 14th magnitude, the ones that are small and concentrated. Aside from the total magnitude, the apparent size determines what is visible in any telescope. It's possible for an object to be on paper bright but when it's spread out across a large area of sky, it can be a challenge to see even in a large telescope. On the other hand, there's a lot of apparently faint objects with a small apparent size whose faint light stands out well against the background sky, at least as long as you're not looking for them from the center of a large city.
Taras
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15-inch F/4.5 Dob under construction
10-inch F/4.5 Discovery Dob
6-inch F/8 Homebuilt Dob
4 1/4-inch F/4 Homebuilt reflector
A whole bunch of eyepieces, filters and other accessories....
Two curious cats
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Bob D.
member
Reged: 06/04/09
Posts: 25
Loc: PA
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Hey,
There are several factors to take in consideration. Not only light pollution effects viewing, but humidity and general air pollution. This will limit your viewing. Your scope is more than capable of viewing many open clusters as well as globular. The real problem would be with the extended low surface brightness objects such as M-33. I think that you should be able to observe most of the Messier list if you were north of the equator. You will definitely see all of the southern Messier objects, things that are tough for the far northern observers. I have on my wish list the large and small Megallantic clouds (were is spell check when I need it  ). They should be easy targets for you.
Cheers and clear skies,
Bob From Phillie
(Cloudy, rainy  )
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