Doubles, SAO and SynScan issues

Kev11 (Kevin) · #1 31-10-2013, 09:14 PM

Without GoTo I would not have considered observing double stars because of the time costs of star hopping or using setting circles. The other problem with double stars, as experienced observers will know, is the archaic and esoteric nomenclature based on discoverers’ names. Eventually, I worked out, as I am sure many others have, that with the help of Simbad, most (not all) can be associated with SAO numbers.

So far, so good: SynScan has SAO Catalogue in my version (3.27). The problems started almost as soon as I began in the observatory – there are gaps in the SAO list in my SynScan e.g. nothing between 288103 and 288827 and lots of other, seemingly random, “missing” stars. It doesn’t seem to be related to magnitude since SAO194544 mags. 8.5 & 8.5 is there; SAO168011 mags. 6 & 8 is not.

I wonder whether anyone can throw some light (sorry!) on this? Is it a possible problem with my SynScan? Is it another example of the neglect of the Southern skies by Northern hemisphere suppliers (it took me ages and lots of searching IIS forums to finally twig that the Octans asterism in the polar scope on my HEQ5 was upside down in the home position as shown in the manual)?

While I am on this subject: is it a fact that SynScan will only slew to objects in its database? To get around the missing SAO numbers I attempted to enter the RA and Dec coordinates, which only seems possible through the User Objects function, another frustration, by the way. SynScan would not respond to coordinates which didn’t match something in one of its catalogues.

I would rather not use a laptop to drive the scope with Stellarium or similar because of the extra power supply issues, but mainly because even the dimmest red screen plays havoc with the dark-adaption of my elderly eyes.

Any help or explanation gratefully received.

Merlin66 (Ken) · #2 31-10-2013, 09:20 PM

Kevin,
Welcome to the club!
Synscan will only goto an object in it's database.....
I ended up using CdC ( to give me the stars I wanted to look at) and EQmod which does allow goto/ slewing to a nominated RA/Dec or a cursor position in CdC.
Such is life....

MattT · #3 31-10-2013, 10:03 PM

Kevin I did Sky Safari Pro by Southern Stars. Use it on my iPod, which is a bit small but doesn't use much power either.
Matt

Steffen · #4 31-10-2013, 10:45 PM

I sometimes use SkySafari on my phone to control the mount, but most often to cross-reference catalogue numbers of objects. SkySafari usually doesn't contain all of an object's catalogue designations but most of them, and is useful to translate to and from SynScan's designations.

For direct RA/Dec GOTO you need to enter the coordinates as user-defined object. You can store up to 25 of them. Unfortunately, you can only refer to them by number (1...25) later on.

Cheers
Steffen.

Kev11 (Kevin) · #5 01-11-2013, 04:33 PM

Thanks Ken, Matt and Steffen. You have confirmed what I guessed was the case. I must say that I am very happy with the HEQ5 mount, it tracks smoothly and accurately, but I am underwhelmed with Synscan. I came back into astronomy with a Celestron 130SLT and the hand controller on that did allow input of any RA and Dec coordinates which overcame any limitations of its in-built object lists. Moreover, the software that came with it allowed one access to the full listing of those objects: Skywatcher doesn't seem to want to let the user know was is or is not in their 13,000 objects database.
The user-generated list of 25 objects in Synscan looks to me like a means to make a "favourites" list or a personal sky tour rather than means of locating unusual objects.
The idea of using a smart phone as a controller is interesting. I don't own one because we are in a poor reception area.
Thanks again for the input.

The Mekon (John Briggs) · #6 01-11-2013, 07:43 PM

Kevin, like you I am interseted in double stars. For this I found the EQ6 and synscan pretty useless as it's databse for doubles is almost non existant. I have to use my 130EDT independant of the goto and use the finder to star hop to do my double star obs.
Two years after I bought my EQ6, I was lucky enough to purchase a second hand SDM with the ArgoNavis. What a joy! the Argonavis has all the bayer, flamsteed stars and more. I often use this reflector now with a 7" off axis mask for double stars and I find this such a joy that the refractor hardly gets a run these days.
Synscan have a long way to go to build a decent database for all observers.