# Using setting circle for Right Ascension

I'm a little bit confused about the setting circle of my EQ5 mount. Basically, I'm trying to find M42 nebula using Sirius star as reference. So, considere that I did the following steps:

A) Polar aligned for south pole
B) Pointed the telescope to Sirius star
C) Adjusted the RA wheel to 6h45m and DEC wheel to -16º42'


Now, I want to view the M42 nebula basing only in the RA and DEC wheels (without using the finderscope or whatever).

Then, I did:

D) Changed the coordinates in the EQ5 mount to match RA 5h35m and DEC -5º23
E) Spent 5 minutes performing the step above (D)
F) Looked in the eyepiece


So my questions are:

1) After doing all these steps above, will the M42 nebula be 5 minutes away from the center of my eyepiece? So instead of using RA 5h35m I will need to use RA 5h40m?(??)

2) If yes, will I need to perform all the above steps every time that I want to see a new object? I mean, as fast as I can, to minimize the RA error...

3) And if the answer is yes again to Question (2), how useful is the setting circle under these conditions for you?

I will appreciate any kind of help.

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• Does it look like the scope was pointing in the direction of M42? You should be able to look through the finder or along the tube to see if it is close to pointing in the right direction. (M42 is visible to the unaided eye if you have a reasonably dark sky.) The setting circle may need to be reversed for Southern Hemisphere viewing if it is not built for both hemispheres. – JohnHoltz Jan 4 '18 at 1:48
• Hey John, thanks for you response. Yes, I can see that it's pointing to the right spot. I know I can find M42 easily, I already took a picture of it. My real problem was concerning the "usefulness" of the setting circle when no clock drive is present in the mount. – Daniel Bonetti Jan 4 '18 at 1:59