Skywatcher ST102

Observing Log Friday 27/10/2017 7-9:30 pm

The forecast was correct, clear skies, a chance to used the skywatcher ST102 bought earlier in year and only used for solar work so far. ( see pic.1)

I started under the carport ,as moon was not visible from back garden, not quite first quarter, used it to complete lining up red dot finder, took some getting use to smaller image after the 8″ Newtonian or the 9.25″ SCT. When at IAS I bought a smartphone adapter to take afocal images using the wifes’ new smartphone, now was on opportunity to try it out, pic.2 shows adapter and phone, pic.3  image of moon, notice the chromatic aberration, however visually it was not noticeable. The image was taken with a 30mm plossl eyepiece with this 500mm focal length refractor this gives a mag of x17. The crater marked with a red dot in the centre is Ptolemaeus, at slightly higher magnifications the centre of crater appeared to have horizontal bands across it, is this an artefact, blemish on objective/ diagonal?? at a mag of x83 (6mm plossl) all was revealed there were shadow bands from the peaks on the Eastern crater wall, the wall reaches heights of 3000m (9000+ ft) and with the sun relatively low on the moons horizon the peaks cast some long shadows, it was fascinating watching the shadows shorten even over a relatively short period of time , Liz had taken her phone back, so I have attempted a sketch of the shadows cast over the crater floor ( see pic.4),  the floor is relatively smooth, having been flooded with lava, some very minor impact craters formed since, the darker shading on the west is due to floor slumping towards crater wall. This was the first time I have seen such marked shadows on a crater floor formed by the crater walls, shadows from central  peaks are usually observed and just blanket shadow from the wall, the continual changing of relative positions of sun and moon makes the terminator a dynamic visual environment, there is always something new to see, even in one evening.

I then relocated to the back garden, starting in the SW with Albireo in Cygnus, the 10mm plossl  ( x50) clearly showed B1 cyg ( Alberio) as a orange red K class star and B2 cyg B class blue star. Taking a line down to zeta Aq from Albireo, bisecting the line from Vega to Altair, just slightly left the Coat hanger asterism fell neatly into the field of view using a 40mm plossl ( x12.5) , normally I would use binoculars for this target, but the wider field of view afforded by this small refractor enables it to be seen in its entirety. Up into Lyra,aiming between Sulafat and Shellak to locate the Ring Nebula ( M57), fuzzy ring but no hint of central white dwarf in this planetary nebula. Continuing west into Hercules M13 and then up to M92, even with 6mm plossl ( x 83) not a lot of detail. Better with the double cluster in Perseus and as I headed to M31, Andromeda galaxy the cloud had rolled in bring the session to a close at around 9:30.

It was nice to get out with some clear skies and I found the AZ3 mount that came with the ST102 easy to use and manoeuvre and although the refractor shows some chromatic abberation as shown by the photograph of moon , visually it was not noticeable enough to be a problem.

here’s to more clear skies!!!

Pete H