…..and yet another clear night in September. At this rate I’m going to be knackered. I’ve also had so many clear nights since this session that I’m way behind on writing up all the observing logs that are now accumulating. I think I can say that September has been my most productive month EVER.
The main reason for opening up was to try a newly acquired toy for the DBO2
I’ve been getting a little fed up with the TMB80 – which is being used as a rather grand finder scope – not being optically aligned with the Big Scope it’s sitting next to. It is quite nice to compare views of the same object through two quite different apertures, as well as having a finder scope that allows me to fine tune the centring of objects when I do larger slews. The Skywatcher offering was the cheaper of the two options I was considering – the other was the ADM Max-Guider Guidescope Saddle – and seems to be quite man enough to handle the weight of the TMB.
I did need to drill and tap the base so I could bolt it onto one of my Losmandy dovetail clamps and the same thing on the top plate to take the TMB scope clamp ring. The whole setup is really quite rigid and the adjustment knobs allow fine and precise control of both axes.
Once aligned, I find that using the TMB as a finder scope more accurate at placing an object into the FOV of a 40mm on the big scope, than does my Televue Red Dot. This is great, as I’m always forgetting to turn the red dot off after a session and always find the batteries flat next time I want to use it.
I didn’t make any observing notes other than the weather detail, so will just comment on generalities as I remember them.
- Date: 18/09/2015
- Time: 22:41 – 00:44 UT
- Seeing: I Perfectly Stable,
- Transparency: I Extremely Clear,
- Pressure: 1015mb,
- Humidity: 85%,
- Dew Point: 9.0 ,
- Wind: 1mph,
- SQM: 19.2 mags/arcsecond,
- NELM: 5.7mag
I’ve always been rather disappointed with the Helix Nebula. Even at the most favourable time, it lurks low in the gloom 20 degree above the horizon and on a number of occasions it’s either completely invisible, or just barely visible. This time was no exception. Being so large, it’s reported by others that the view is better through a smaller scope. While I could make it out in both scopes, the TMB didn’t offer anything more than it’s 254mm brother. I was able to make out the extent of outer edge but no structure, or the hole at the centre was discernible. I only have an OIII and an UHC fitted to the big scope, but no improvement was made with either of them. Basically it looked just like a large galaxy, but one without a core…..very dissapointing.
No nebulosity seen
Nope. Can’t remember anything about this.
Absolutely wonderful through the Altair 250mm f/8 RC, 14mm Delos, 145 X, 29.8′,
Without any filer, it’s big, but very faint and with averted vision, I can just about make out the bite marks at the waist of the Apple. But apply either filter and the whole nebula just jumps out of the background. If you didn’t have an OIII then you wouldn’t be disappointed with an view through a UHC, but the OIII really had the edge on contrast. Great Stuff.