What a super-duper night I had splitting 6 doubles in Lynx.
I had set up my Williams Optics 158 mm F/7 apochromatic refractor and my W/O 70 mm small apo in my usual place - the back garden before sunset which occurred at 8.10 local time. Mirror diagonals are fitted to both scopes. And both scopes are supported by a Berlebach Planet alt-az mount. I had to change the position of its legs to make sure my focuser did not have a problem reaching up to the Lynx constellation. That can be a major nuisance - as Lynx is reasonably close to my zenith. Temperatures went down from 10 to 2 degrees Celsius during the course of the late afternoon and the night.
1. I could see Venus with my own eyes at 7.08 pm local time. That's one hour 12 minutes before the Sun had left the Irish sky altogether. Through my small 70 mm apo I saw it still had a half phase. But all that changed in my main scope. At 40X it was evident the phase was more like the correct 43.5% which Guide 9.1 DVD states. At 112X and 140X, the goddess of love was truly looking very good and steady. There was no shimmering. Venus right now has reached -4.6 in magnitude. She was 91,060,000 kms from Earth and had an angular diameter of 27.4" on this late Monday afternoon.
Shimmering was more pronounced at 167X and 225X. She is still a decent planet to observe as April continues. I recommend her to anyone.
My figures can be found on
www.stelledoppie.it
for these doubles.
2. It is possible to see Alpha Lyncis with the unaided eye. Its magnitude is quite bright at +3.1. It is an orange star to my eyes and in any finder; and an important star because it guides us to the rest of these doubles. They can all be observed less than 6 degrees from Alpha. And some of them are extremely nice if not spectacular.
3. 38 Lyncis I have reported on before, but it is a very beautiful true binary. Magnitudes: A = 3.9. B = 6.1. Sep = 2.5". PA = 229 degrees. Stunning split at 112X. But who resist increasing that to 140X, 167X or even higher? Both stars appear white to me.
4. Less than 2 degrees south we have an uncertain but beautiful double: Stf 1333. Magnitudes: A = 6.6. B = 6.7. Sep = 1.9". PA = 50 degrees. Two white stars almost identical with the tiniest black gap between them at 112X. They look similar to 2 eyes. I'm certain Friedrich Georg Wilhelm Struve was most impressed with his discovery of Stf 1333.
5. Stf 1339 is another uncertain double. But it is very lovely too. Magnitudes: A = 9.2. B = 9.9. Sep = 1.5". PA =65 degrees. It needed that bit more magnification to split but not by much. 140X is perfect to see both stars with the slimmest black gap in between. 167X and 225X show the pair brilliantly also.
6. ES 1735 is an optical double and is directly east of 38 Lyn. It most certainly is a real challenge to see the two stars. Magnitudes: A = 10.1. B = 10.6. Sep = 4.4". PA = 186 degrees. With those magnitudes and separation you would think it ought to easy to see them both. But with the almost full Moon shining very brightly at -11.7, these 2 little fellows just would not split at 112X, 167X or 225X. I required a William Optics 4 mm eyepiece to split it successfully. Perhaps when the Moon finally leaves our skies I might have a better time with ES 1735. ES stands for Thomas Espin who lived from 1858 to 1934. He was a priest of the Anglican church.
7. Stf 1338 is a true binary which was my ultimate prize of this Monday night. Magnitudes: A = 6.7. B = 7.1. Sep: 1". PA = 322 degrees. As I was preparing for these observations I thought I would have had great difficulties with Stf 1338. But I was nearly splitting him at 112X. I then put in my ancient TMB 8 mm eyepiece which gives 140X, and behold I had a very tight separation. I was enjoying the success so much, I did increase the magnification to 167X and 225X. This proved to be very advantageous. The two stars looked razor sharp. (It truly was a very good night for close doubles.) There is a minimum delta magnitude of 0.4 difference after all to Stf 1338. I would have thought I would require at least 280X to split Stf 1338. How wrong could I have been! Do consider showing this amazing double to your immediate close family. Once the Corona Virus is gone for good I, for one, will show it to my astronomical friends. That will probably be in 2021 and beyond. Stf 1338 is that good! It definitely is my new favourite double star of 2020. Both stars are yellow-white. It is breathtakingly magnificent!
8. Right next to Stf 1338, there is another true binary. AG 164 has magnitudes: A = 10.3. B = 10.5. Sep = 4.6". PA = 19 degrees. I did get a split at 112X, but both stars are very dim. So I increased up to 140X and 167X. Good views were had at that point. The two stars are yellow-white too.
In closing, there is a rumour we have clear skies again tonight Tuesday 7th April. I could do with seeing one or two carbon stars in Lynx. So watch this space!
I have to prepare some maps first.
Thank you for reading my report.
Comments are very welcome as always.
Clear skies, everyone.
Aubrey.
RS Ophiuchi is the number one target there plus a few others. There's something quite serene looking at the night sky at that time of the morning.
  