Celestron Starsense Autoalign part 2

Having had a chance to play with the Celestron Starsense Autoalign (SSA) nearly every day since it was purchased, I thought I would share my experiences with it and what I have learnt from all this.

Since getting the SSA, I have been more willing to use the Celestron CGEM mount I have. Even the previous tasks of collimating the telescopes, polar alignment are less of a chore, as I know the SSA will take care of the rest for me.

These are the things I have learnt over the last few days:

1) Always remember to take the cover off the Celestron Starsense autoguiding camera – it helps if the camera can actually see the stars.

2) If there is patchy cloud, the camera can still pick up stars which are not cloud-covered – so worth a try anyway. If it is dense cloud, it will simply say too few stars and not be able to do the alignment.

3) I did not set the internal clock after the first installation. When I checked on Monday night (a few days later), the mount had a time which was nearly 10 minutes behind. This will matter as it means that the calculations of the stars will not be as accurate. So it is best to recheck the time (I use the universal time clock on the internet to do this) and ensure it is accurate.

4) If you do collimate the telescope, then expect the calibration for the offset of the camera to the telescope to be off. So a recalibration is needed for this.

5) Ensure the calibration of offset is correct before attempting polar alignment, as otherwise it will be off. My polar alignment is now consistently viewable within my 5mm reticle eyepiece, which means it is really close.

6) As I can see the stars on live view with the Olympus E-PL5 with my 8″ Astrotech Ritchey Chretien 1600mm F8 telescope, I expect that I will be able to see even more stars with the Sony A6000 – so no need for Bhatinov masks and test shots to get the focus right.

Anyway, here are some shots I took with my Olympus E-PL5. The first is of Jupiter and three of its moons during the opposition of Jupiter when it was closest to the earth. I will need a small imager if I want to capture more detail from Jupiter (especially now that I have collimated my telescope).

Jupiter with three moons
Jupiter with three moons
Jupiter with three moons cropped in
Jupiter with three moons cropped in

The second if of the Whirlpool galaxy (5×2:30min subs stacked together) which unfortunately was during a night of poor seeing, with light pollution from the near full moon up in the sky. Compound this with the fact my telescope was not well collimated and I was still experimenting with this new setup for imaging. Hence I did not expect very much from the shots at all.

But the biggest problem I encountered was that my focuser did not have enough reach with my camera to achieve focus, while my 80mm 2″ extension tube was too long to achieve focus as well. In the end the camera was mounted directly to the focuser with its T2-2″ adapter jutting out by a few cm, which is not the most stable or well-centered way of mounting. But despite all this, I thought it managed reasonably well.

As I had the polar alignment very close through the All Star Polar Alignment procedure through the SSA, the CGEM managed to achieve long subs without guiding (previously I could only achieve 2:30min subs with guiding). The SSA even managed to get the Whirlpool right in the center of the camera sensor without me needing to adjust.

Whirlpool galaxy with 5x2:30min subs ISO 3200

Whirlpool galaxy with 5×2:30min subs ISO 3200

I expect that I will get even better results now that my telescope is collimated and if I apply permanent periodic error correction (PEC) to it – which I will do with my guider camera when I next get a chance. I have now managed to update my Celestron CGEM Motor control firmware to 6.50, and my Lacerate MGEN auto guider to the latest firmware version 2.12. So now is just a case of waiting for when I have the time to use them.

Boon