Observation Highlights -4th May 2017

Hello, everyone.
Let me give you some of Thursday night's highlights with my William Optics 158mm apochromatic refractor.
It was windy in Dublin; so I could only go up to 167X. But the sky was very clear between 8.30 pm till the end of my session at 11 pm.
1. I started off with the 8 day old gibbous Moon of course.
Apart from seeing my favourite lunar feature Rupes Recta, I was thrilled to see the rarely sighted jagged shadows inside the wonderful walled plain called Plato. They were very strong at 167X and jet black in appearance.
2. Algieba (Gamma Leonis) looked magnificently split at 112X. The 2 components have a separation of 4.7 arc seconds. The primary is orange -yellow and the secondary is yellow. It still takes my breath away as it has done for many years. The PA is 127 degrees. The magnitudes are 2.4 and 3.6.
3. Iota Leonis is a very fine double star separated at 112X. An enquirer asked me on Cloudy Nights asked me to check out its colours. Yellow and slight blue for me. Separation: 2.175 arc seconds. PA: 94 degrees. The magnitudes are 4.1 and 6.7.
4. There is a double double in Leo. The stars are Tau Leonis and 83 Leonis. Both wide pairs are finely split at 11X in my 70 mm apo. But I greatly enjoyed the colours at 40X in my main scope. both primaries are yellow white and both secondaries are white to me. The separations are 88 arc seconds and 28 seconds. The PA's are 164 and 149 degrees. The magnitudes are 5.1 and 7.8, 6.6 and 7.5. There quite a few bright field stars too.
5. Jupiter was getting nice and high in the sky. At 11 pm, I could just about see Europa's shadow in the centre of the North Temperate Belt at 140X and 167X.
6. Lastly, Porrima (Gamma Virginis) was plain to see a bit north of Jupiter with my own eyes. The good news is its 2 components are continuing to widen in recent years. The separation is now 2.6 arc seconds. So I can split both stars at 112X. The magnitudes are both +3.5 and the PA is only 2 arc seconds. That is straight down for me.

Thank you for reading.

Aubrey.

Excellent Aubrey. Can I ask if you've ever picked out the craterlets on the floor of Plato? I've seen some reports on Cloudy Nights suggesting it could be possible with a 6-inch.

Thank you for your question, Finbarr.
Maybe it is because I rarely have time to study Plato.
The Sun needs to be shining at the right angle into the crater.
I have never succeeded in observing any craterlets as yet.
On this occasion, those jagged shadows would have prevented me from seeing them.
It was quite windy last Thursday night.
This would have prevented me from using higher magnifications.
On a calmer night using, say, 225X or 280X, I would be more successful to winning some craterlets -especially as I have at my disposal a 6.2" apo.

Clear skies,
Aubrey.

P.S. As I am out tonight, I won't have the opportunity to observe The Moon very near Jupiter.