Observations - 12/05/23

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Observations - 12/05/23 was created by flt158

Hello friends. 

I had my William Optics 158mm f/7 apochromatic refractor in my back garden on Friday night 12th May 2023. Also attached was my usual small WO 70mm f/6 apo that I use as a finder scope. The air temperature was between 13 and 11˚ Celsius. The wind was completely non-existent.  I had dew the night before. So I had to clean both scopes and decided to clean 8 of my 9 eyepieces. That took up nearly 2 hours of my time earlier on Friday. But I didn’t mind. I was ready to do some observing – even though the nights are getting short. Sunset happened at 21.13 local time. 

1. With my little 70mm apo I found Regulus a little after 21.30 local time. That's 17 minutes after sunset. I could see it clearly at 11x. Good start! But I needed a full 112x to see its faint secondary. 

2. Of course Gamma Leonis (Algieba) came next. Both golden yellow stars were cleanly separated at 112x as per usual. 

3. I went back down to Regulus and star hopped up to 34, 37, 42 and finally to 46 Leonis. This latter star is an M class sun and it appeared as a good orange star at 40x. Straight up from it was my first time observation of STF 1446 and it is listed in Robert Burnham’s Celestial Handbook. On www.stelledoppie.it this double has magnitudes: A = 9.3. B = 10. Sep = 5.5”. PA = 250˚. A lot of stars were still invisible, but I found my little treasure. Both stars were white. I had no separation at 40x. But my newly cleaned Pentax 10mm did the business. 112x was sufficient to see both stars with a nice small black space between – even though the sky was nowhere near dark. What a real thrill! By the way, I searched Google to see if anyone else had a successful split of STF 1446; and I discovered that our very own Paul (Lunatic) got a good split of it some 13 years ago! Good memories, Paul. I have always known that Paul was and is a great double star hunter. 

4. As 49 Leonis (STF 1450) is about 5˚ to the south, it was a good time for a revisit. Magnitudes: A = 5.8. B = 7.9. Sep = 2”. PA = 157˚. In the past I could split it at 112x. But this time I required 140x. No harm at all. It looked very good at 167x too. Paul also has had success with this double.

5. And so I was very keen to estimate the magnitude of R Leonis. This variable star is increasing in brightness all the time. As you know I adore its beautiful red rose colour. Over on www.aavso.org I have estimated its magnitude as +6.2. The star is definitely brighter than +6.4 mag 19 Leonis. I would love to see it match the other bright star in the same field of view – 18 Leonis. Its mag is +5.7. By the way, all 3 stars are easily visible at 11x with my small apo and 40x in the main scope. As Valerie had one of her closest friends with us, I had to show them both this amazing star.   

6. Polaris’ companion continues to revolve around its bright yellow-white primary. That’s because of our Earth’s spinning axis. With my main refractor it’s now at 6 o’clock and heading towards 7 o’clock. Call it half way if you wish. 

7. Finally, as it was now after 22.30 local time I was keen to observe S Cephei again. I found those 2 stars Rho 1 and Rho 2 Cephei and immediately I could see S Cep next to them at the lowly magnification of 40x. At 112x S Cep stands almost alone in the fov and is distinguished by its ripe tomato red colour. I don’t think its magnitude has changed: +8.6 since last time. The star is circumpolar. Therefore I can keep an eye on it over the coming months.  

The dew was threatening to return again. So I ended this observing session.  

Clear skies from Aubrey.  
The following user(s) said Thank You: michael_murphy, Fermidox, Until_then-Goodnight!
2 weeks 23 hours ago #111848

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Replied by Until_then-Goodnight! on topic Observations - 12/05/23

Hi Aubrey, 

Nice report, and I'm glad you got some observing in on Friday evening. Well done on estimating and recording your estimated magnitude of R Leonis...looking forward to reading how it gets brighter of the next while.

Clear skies,

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Last edit: 1 week 6 days ago by Until_then-Goodnight!.
1 week 6 days ago #111852

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Replied by flt158 on topic Observations - 12/05/23

As am I, Darren. As am I!

I was amazed how clear the sky was. 
There simply was no cloud whatsoever.    

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1 week 6 days ago #111853

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