What magnitude can I see?

[kiwidoc66]

Hi there
Learning to drive the new 200mm skywatcher dob. I've been pleased so far with views of 47 Tucanae, Orion nebula, Tarantula nebula and Jewel Box in Crux. A (minor) problem is that in my main observing site (back garden) trees block view to ~30 degrees above horizon and best viewing is at zenith. I went looking for NGC55 but the sky was fairly light with the moon and light pollution. At mag 7.9 should I have been able to find it? (I wondered if I did - a short linear faint fuzzy blob with a brighter blob at either end close by alpha phe... ). Advice on what I can expect to see welcome! Also, what some good "targets" are given the limitations of the viewing site.

[Blue Skies]

In an 8" - yes! But with the moon as big as it is - no. You should wait until there is no moon in the sky and try again.

[saberscorpx]

DSO can also stand for Dark Sky Objects.
Even a 20 minute drive away from city lights can make the difference between detection and detail.
12-13th mag fuzzies are within the grasp of an 8" given excellent sky conditions.

A good 'rites of passage' southern sky list for binos or scopes can be found here:
http://www.astroleague.org/al/obsclubs/sskybino/ssbinoc2.html

From darker sites one can also dive into the following list of telescopic treasures:
http://www.astroleague.org/al/obsclubs/southsky/sskylist.htm


SJS

[glenc]

You will be able to see NGC 55 with your 200mm but you need to drive out of town when there is no moon.
Here is a list of 95 objects to look at: http://www.iceinspace.com.au/forum/showthread.php?t=18551 (See #42)
The magnitude limit for 50mm binoculars is 10.8 and for a 200mm scope it is 13.8 but that is for stars not galaxies.
For galaxies try magnitude 9 and 12.

[kiwidoc66]

Thanks for the advice. I'll try and work through the lists :).
BTW, I've found this program http://astrohelper.myvnc.com (http://astrohelper.myvnc.com/) that calculates alt-az coordinates for NGC, Messier and other objects, allows you to adjust the horizon and print a list of objects visible at any time.

[erick]

I'd like to look at AstroHelper, but I'm getting a bad link. I have searched for alternatives but all send me to the same place, eg. http://casazza.myvnc.com/astrohelper/

Can anyone direct me to a copy of AstroHelper, please. :help:

I have read:-
AstroHelper v0.0b (http://casazza.myvnc.com/astrohelper/) Home Page: http://casazza.myvnc.com/astrohelper/ Mark Casazza
Version Release Date:
Shareware version: Freeware
Filename: astrohelper.zip Size: 3.4 MB
Details: Astro Helper will tell you the angle of elevation above the horizon (altitude) and the direction in degrees from North (Azimuth) of the selected objects. It will simultaneously display the coordinates of 22 objects from a database of over 22,000 objects. With these coordinates you can point your Dobsonian mounted telescope or other Alt/Az mounted scope. If you have an equatorial mounted scope these values will not help you at all, sorry.


EDIT: - Update - I've found the author's website and have it now:- http://casazza.net/astrohelper/
(http://casazza.net/astrohelper/)

[kiwidoc66]

Sorry about the bad link - the http://casazza.net/astrohelper/ one is correct