Observations - 27th May 2020

1 month 1 week ago #108967 by flt158
Observations - 27th May 2020 was created by flt158
Hello friends.

I set up my William Optics 158 mm F/7 apochromatic refractor and its WO 70 mm F/6 small apo on the Berlebach Planet alt-az mount in the back garden quite a while before sunset.

Sunset occurred at 21.37 Irish Summer Time. Temperatures hardly changed during the 3 hour period: 12 degrees down to 10 degrees Celsius.

1. Spot on 21.00 I found Venus in my main scope at 40X as the extremely crescent was engulfed by high and quite dense cirrus clouds. I was utterly amazed. I have memorized where I should find the planet by the use of distant trees. For the record, Venus' magnitude was -4.0. Its distance was a little less than 144,000,000 kms from Earth. Its angular diameter was a large 56.3".
But at the time I was observing herself, her illumination was 1.8%. Wow! Soon afterwards I could see Venus using my small 70 mm apo at 11X despite the awful sky conditions. I observed Venus for a full 30 minutes. Tonight, Thursday, the poor sky conditions may persist. But I am planning to give the brightest planet another shot.

The sky was never really clear. There were some high and hazy cirrus clouds during most of the 3 hour observing period. I found golden-orange Arcturus before I could see it with my own eyes in the southern sky using my small 70 mm apo at 11X. Then, as usual, I was splitting Pulcherrima Izar from magnifications 112X, 140X, 167X and 225X. (I just thought to treat myself with that high power.)

Off to Corona Borealis then and I could barely see Alpha Coronae with my unaided eyes at about 22.45 because of the poor sky conditions. I only had time to observe 4 doubles before midnight occurred.

All my upcoming figures are from the ever reliable website www.stelledoppie.it

2. Omicron Coronae is an optical double. Magnitudes: A = 5.6. B = 10.5. Sep = 144.3". PA = 343 degrees. Of course there is no problem splitting it at 40X. At 112X I could easily see that A is K0 orange. B is white.

3. I then wished to treat my wife to STF 1941 which I had seen 4 nights ago. I showed her this dim uncertain double at 225X. And she was pleased at its sight. The refractor has no hassles seeing A & B split at 140X. Magnitudes: A = 9.7. B = 9.8. Sep = 1.4". PA = 212 degrees.

4. STF 1932 is a true binary; and it is the first entry in Robert Burnham's Celestial Handbooks in this constellation. What a magnificent sight it is! Magnitudes: A = 7.3. B = 7.4. Sep = 1.6". PA = 267 degrees. The 2 stars are side by side like 2 eyes looking at us. I had the slenderest of black gaps between them at 112X. But others might find 140X or 167X better options. I could see the slightest yellow-white F6 colour in both stars. But that wasn't always possible. Still STF 1932 is the real winner to me on this Wednesday night. I'm sure some here have observed this superb double star. Those who haven't, I would encourage you to give it a go!

5. Finally, STF 1936 is an uncertain double which is very easy to split. It's right next to STF 1932. Magnitudes: A = 9.9. B = 10.1. Sep = 19.8". PA = 231 degrees. No hassle splitting it at 40X. But the colours are far more entertaining at 112X. A is F2 yellow-white. B is K0 orange.

So, in summary, my 3 first time doubles were Omicron, STF 1941 and STF 1936.

Thank you for reading.
As midnight occurred it was off to sleep for me.
We seem to have more hazy nights ahead of us.

Clear skies to you all on IFAS from Aubrey.
The following user(s) said Thank You: michael_murphy, Fermidox, scfahy

Please Log in or Create an account to join the conversation.

1 month 1 week ago #108968 by Until_then-Goodnight!
Replied by Until_then-Goodnight! on topic Observations - 27th May 2020
Hi Aubrey,

Very many thanks for another great observational report. I liked reading about your technique of using distant trees to locate Venus at 9pm. Also well done, on splitting Izar last night - those clouds were a real nuisance. STF 1932 sounds like a nice double, so I'll hopefully give that a go when the sky clears.

And speaking of clear skies, I tried to observe the Moon this evening and tonight, but the high clouds played havoc, so I'll try again tomorrow.

Until then, all the best,

Darren.
The following user(s) said Thank You: flt158

Please Log in or Create an account to join the conversation.

Time to create page: 0.065 seconds
Powered by Kunena Forum