The calm clear sky last night provided an opportunity to try out a new gizmo. I picked up a second hand Celestron SkyPortal WiFi dongle recently, and put it to the test yesterday evening. In essence, it plugs into the handset port of compatible mounts and creates a local WiFi network so that you can connect to the mount using a mobile device (iOS or Android) and control it using an app on your phone. The app on the phone can do all of the stuff that you would use the handset for, only better, because the connection is wireless so it is tidier, and because the app can be much more sophisticated than the handset software. So, did it live up to the marketing claims?
Setup was simple on my venerable CG5 mount, just unplug the handset and plug in the WiFi module (it can be plugged into aux ports on other mounts). I then connected my phone to the new network and set it not to go to sleep so that the connection would not be lost. I found out the hard way that if the phone locks itself after a period without use, the connection, and the alignment, are lost and you have to start from scratch. Next step is to fire up the app. I used SkySafari Plus which cost E15, but a free version by Celestron called Skyportal, with fewer features, is also available. Tapping "Connect and align" guided me through a process very similar to the "Two star align" routine on the handset. Soft buttons on the screen of the phone replace the direction buttons of the handset in this process and they remain available all through the session so that you can nudge a target around the fov. I messed up the first time I tried because I hit the wrong icon on the phone; with a small screen it requires some care to avoid doing this. Second time round everything went smoothly and GoTo accuracy was very good all across the sky, putting every target into a 26' fov.
Choosing targets was a breeze. SkySafari is a planetarium app so you can just play around on the map and hit "Go to" when you see an object that you would like to observe. I did that for a few perennial favourites like M13, M92 and NGC 7662, the "blue snowball nebula", and also for Uranus and Neptune. Alternatively the app allows you to search its built in catalogues (approx. 3 million objects), using several criteria, in order to create observing lists. I had prepared a list of some double stars in Andromeda, and hitting the "highlight objects" button highlighted all of them on the map. I then worked my way through a selection of them, choosing ones close to each other to minimise slewing, summoning an "info" page to get a sense of the target, and hitting "GoTo" when I was happy with the target. A real bonus is that you can also record observing notes in the app. I found that really feature convenient, and typed brief notes while sitting at the eyepiece, no need to scribble notes or move to a computer. I rattled through ten targets in less than an hour in that way, and even had time for a cuppa along the way. Being able to select targets from the map on the phone had the added benefit that I had a much better sense of where the targets were in the sky. I have found that using a PC to control the mount has the same effect on me as using a sat nav, it gets me to where I want, but I often have little idea where I am.
All in all, I was very pleased with the SkyPortal. It is so convenient to have your mount control, your sky map, and your observing notes, all combined into one little package that you can pop into your pocket while you are looking though the eyepiece! The app is nowhere near as comprehensive as the planning sofware that I normally use (AstroPlanner), but it is perfectly adequate and wins hands(et) down in the convenience stakes. The setup should work just as well in the wilds of Wicklow as in my back garden (no internet required), hopefully there will be an opportunity to put that to the test soon.
Here's a selection of my notes from last night.
STF 79: 6.1, 6.8, 8". Fine pair of bright stars standing out in a sparse field. Widely separated at 113x, the secondary is bluish and the primary white.
STF 154: 8.5, 8.8, 5". Matching pair of faint white stars, wide at 191x
STT 21: 6.5, 6.8, 1.2". Bright white star, barely resolved from a fainter secondary in moments of steady seeing. Quite a challenge at 191x.
STF 52: 7.7, 8.9, 1.4". Unequal white stars, split by a hair at 191x.
STF 40: 6.5, 8.5, 12". Bright, golden primary nicely separated from a fainter, paler companion using 69x.
STF 33: 8.1, 8.9, 2.8". Matched yellow stars, barely resolved at 69x, still nice and close at 113x. Very nice delicate pair.
ADS 285: 6.9, 8.3, 1.8". Unequal, pale yellow stars, beautifully close at 113x. A brilliant golden star dominates the field. Very fine.
Pi Andromedae: 4.3, 7.1, 36". Brilliant bluish primary with a much fainter secondary. Too wide to be really attractive.
As an aside, before wrapping up for the night I stopped the scope (a 120 mm refractor) down to 50mm and checked Vega and Altair at 113x to see the Airy disk. It was the first time I tried this trick and luckily the seeing was good by Irish standards so I got a decent view. The first and second diffraction rings were clearly visible much of the time and I reckon the seeing was about 6 on the Pickering scale.
Thanks for reading.
Mike
Skywatcher 120 mm ED on a CG5 mount.
Orion UK 300mm Dobsonian
  