Notes From The Field - A little post-sunset fun

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Apollo XX
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Notes From The Field - A little post-sunset fun

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June 17th, 2022 – Early Evening;

8:35PM, 15 Minutes Post-Sunset; We’re nearly three full weeks into June now and we’ve had no clear nights with a dark sky yet. Yes, we’ve had lunar nights, four of them in fact, but for those of us with deep-sky observing objectives the opportunities to observe them this month have been precious few. It’s looking like that could change on this night, and now all I have to do is wait until it gets dark enough to see my targets. Given that my most challenging target is traipsing off towards the west in the sky now, this means waiting until at least 10:30PM to start hunting it. What to do in the meantime?

If you’ve been following Phil Harrington’s monthly observing challenge on Cloudy Nights recently, then you’ll know that this month’s challenge project is to see if you can split the Epsilon Bootes system (Izar) in a small telescope (Phil lists a size range of 3” – 5” as suggested apertures to try). Earlier in the week I took on the challenge with my old classic Celestron 60mm F/15 achromat and came up with the gold at a power of 200x. It’s something that I’d done before with that scope, but it was still fun to do it again.

In the comments section below Phil’s article one of the contributors mentioned splitting Izar in a daylight sky. Now that sounded interesting. I’ve always been fond of off-the-beaten-path challenges, and this sounded like it was right up my alley. At just fifteen minutes past sunset I pulled out the old 4.5” F/8 Newtonian reflector to give it a go. While not “officially” daylight, the sky was still quite bright and blue and I thought it a good enough representation for a first try. The old dobsonian-mounted scope has a nice set of alt/az setting circles on it that should give me a leg up on the finding process. Would they?

Plunking down the base and roughly leveling it, I took an educated guess as to where south (180°) was and dialed in the azimuth scale. With the base level the altitude scale would be accurate, and that would be a big help. I put the OTA on the base and punched up Arcturus in my Stellarium phone app. It told me that the popular zero-magnitude star was at 159° in azimuth and 66° in altitude, but of course the sky was so bright that the star was purely invisible to the naked eye. That wasn’t the case in the finder scope though, and in a matter of less than a minute we had the first step of finding Izar under our belts.

Using Arcturus to calibrate the azimuth dial, I now had everything I needed to land Izar. It’s sometimes surprising what direction things have to be moved to the next target, and such was the case with this one. We all know that Izar is the next star up the side of the “kite” in Bootes, but the azimuth had to be a moved nearly 30° to the east and 5° to the north to land it. I probably wouldn’t have gotten that without the help of the dials.
Now with Izar in the eyepiece I didn’t even bother trying a range of magnifications to see which one would work best. I pulled out of the case a 12mm eyepiece and a 3x barlow and dropped them into the eyepiece holder. This gave me a magnification of 225x in that scope, and the view of Izar and its companion was splendid!

While this particular attempt was definitely conducted during what most people would consider ‘daylight’, the high magnification made the view in the eyepiece quite a bit darker than you might imagine it would be given the brightness of the sky. I’m hoping my next attempt can occur before sunset when the sky will stay blue in the eyepiece field of view with Izar and its companion just sitting there looking back at me. It’s looking like July might be an ideal time of year to try that, so we’ll try it then.

Izar Daylight Spilt Challenge.png
Izar Daylight Spilt Challenge.png (176.61 KiB) Viewed 93 times
Who's up for a little daylight split of Izar challenge? It's quite doable, very different, and kind of cool in the sense that at a time of year when we typically sleepwalk to our scopes we can be doing what some would call serious stargazing at such a convenient hour.

Keep Looking Up!

Mike McCabe
"The purpose of life is the investigation of the Sun, the Moon, and the heavens." - Anaxagoras
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Pete
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Re: Notes From The Field - A little post-sunset fun

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I'm just blown away with this posting Mike. Talk about doing things the hard/old way.
Pete P.
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Apollo XX
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Re: Notes From The Field - A little post-sunset fun

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Hi Pete,

Old way perhaps, but not hard at all! Just a little fun challenge for the heck of it!

Mike
"The purpose of life is the investigation of the Sun, the Moon, and the heavens." - Anaxagoras
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