GoTo misses target

[rubecula]

I sent the scope to the Iris Nebula (NGC 7023) and took a couple of test images.  Couldn't see any DSO so I moved the the Fireworks Galaxy, took an image and it was there in the centre.  I presumed that the Iris must have been too feint to show in a 300 sec image.

The following day I stretched the "Iris" image and there was still nothing visible. I then checked the image at Astrometry.net and saw that the mount had completely missed it.

The fact that it found the Fireworks Galaxy suggests that the GoTo was correctly aligned.  Was this something I had done wrong or an error in the GoTo database?

Thanks

[Yamez]

I'm unsure, my goto does this aswell. I would like to know the answer as well.

[barrie greenwood]

Had this issue myself and found some objects were spot in central of the ep and then others were a yard off

The cause was the stars I chose to do the initial alignment if they were not spaced out to give a good spread if the sky it allowed it to pick out some objects well and others not very good at all

I now align with stars as far spread as possible and I am fairly consistent

Hope this helpd

Baz

[ronin]

When you select the object and request the goto action does the handset not give the RA and Dec of the chosen object? May not, the Meade I have gives the names etc not sure about the RA and Dec bit - simply never bothered to read it in detail. Just thinking that it may be worth recording the RA+Dec values and then checking it what is in the handset data matched something like Stellarium.

Might be able to do this from the handset without actually doing a full setup.

Just hoping to determine if the handset data is incorrect. If it is not then equally not sure what can be done as I am not sure if the data file can be editted and saved back.

[noah4x4]

3 hours ago, barrie greenwood said:

Had this issue myself and found some objects were spot in central of the ep and then others were a yard off

The cause was the stars I chose to do the initial alignment if they were not spaced out to give a good spread if the sky it allowed it to pick out some objects well and others not very good at all

I now align with stars as far spread as possible and I am fairly consistent

Hope this helpd

Baz

I use Starsense and it's interesting to watch its motion. Like you Barrie, it initially selects three sectors of the sky as far apart as possible. It is really good, but I noticed that accuracy diminished very slightly in any sectors it had NOT selected.

However, I have since added a further 10 alignment points. These each seem to mimic the SYNC function that improves accuracy around a selected star. By performing this on 10 different sectors that now embraces most of the sky. I now get awesome results in any direction.

Whilst this might not be possible without Starsense,  I think it highlights that it is desirable to select three stars as far apart as possible with differing DEC when using traditional alignments. Your experience does seem to endorse this.

[rubecula]

Thanks for the input guys, you've given me somethings to think about. My scope is pier mounted and well polar aligned (with a Polemaster) so I only did a two-star align.  What also confused me was that it got one target right and one wrong when the two are not thatt far apart in the sky.  I'll investigate the RA/DEC that the scope slews to and compare it with Iris' actual co-ordinates.