26 March, 2017

Changing season also requires some changes in the observatory equipments' settings. Onw of these changes is the mechanical difference of focusing point in the TCF focuser.

I try to delay it as long as i can, because it required some more changes in the telescope and the mount.

Last night, the focuser got focused (and poorly) at around step 100 in TCF Focuser. I knew i wont be able to focus the next day.

So this evening, i performed these steps:

1. I opened the locks of the mirror cell of C14.

2. Set the TCF Focuser at 4000 step.

3. Put the Bahtinov Mask on C14. 

4. Slewed the mount to Dubhe, a bright star in Ursa Major.

5. Changed the focus knob of C14 until the three lines were in the desired position My CCD was still attached and was taking 1 second continuous images which was being shown on my computer in the human room.. i was watching and controlling the software on the iphone though).

6. Took off the Mask from the front of the telescope. 

7. Locked the Mirror Cell.

8. Collimated the Secondary Mirror using Bob's Knobs. 

9. Adjusted the pointing model, which changed a little. 

Went to the Human Room and refocused the star from The Sky X Pro software. It got a perfect focus at 4231 step. TCF Focuser has 15.2 mm of tube travel with zero backlash. It covers this distance kn 7000 steps.. talk aboit precision focusing!!

I wanted to image M81, but a lot of time was lost and the observatory wall was in the view. Still i got a few minutes on M81.

Next i moved on to M87.. this is my second attempt on imaging the jet of this galaxy. Focused the system again near the galaxy, found a guide star, rotated the imaging train, calibrated the mount and the adaptive optics, initiated autoguiding at 3Hz, started taking 5 minutes exposures. 

Thin clouds were in the sky for a while but the guide star did not vanish so i kept going. 

Got 3 hours of exposure in the end! Will process these frames in a couple of days.