Some Leo Doubles

[Pixies]

The third clear night in a row! I was planning on some faint fuzzies in Coma Berenices, but once I had set up, I could see that there was a slight haze. So I changed tack and made a quick list of some doubles in Leo. I made up a list from some of the entries in "An Anthology of Visual Double Stars" (Argyle, Swam & James) and another one I wanted to try was Kappa Leonis - after it was mentioned earlier today by a couple of posters.

I started on Tegmine, to see how the seeing was. It was variable but OK. I could just 'notch' the tighter pair at x170 - a far cry though, from the recent nights of excellent seeing. Perhaps not the best night for tight double stars then.

First one was Kappa Leonis. Perhaps not the best idea, at a 2.2 arcsecond split, it doesn't sound too bad. But the magnitude differences are +4.46 and +9.70 and with the seeing conditions, it wasn't to be. At times I thought I had seen it, but it might just have been watery eyes (from the cold breeze). The next time we have some excellent conditions, I'll try again.

Nearby was the galaxy NGC 2903. At magnitude +8.79, it's a bright one, but it was pretty faint and only observable with averted vision. So the sky conditions were as I had thought. So on with the doubles...

Next was Omega Leonis. A very very tight 0.9 arcseconds. I managed to get a notched split at x300 with the 2 airy disks popping into clear distinction every now and again.

Gamma Leonis (Algieba) was a pleasantly easy split at x80. The main star yellow and the secondary a slightly cooler pale yellow.

Now then: 54 Leonis. This was a great double and is now one of my new favourites. I could just make a split at x40 but it looked better with a little more magnification. x75 was nice. Both stars a cold steely blue/white.

Back to the trickier ones with Iota Leonis. This one is another with a big magnitude difference: +3.96 and +11.06 and a distance of 2.3 arcseconds. This one I'm pretty certain I got. the small faint secondary trailing in the wake of the main star. I hope I was right - but I don't know how I saw this one and not Kappa Leonis, which should be easier. Perhaps it was just a few moments of good seeing. It was a bit later in the evening.

Struve 1555 - at 0.62 arcseconds, this is supposedly at the limit of an 8" reflector. Tonight, no chance.

It's going to be cloudy tomorrow. 

Edited April 4, 2021 by Pixies

[John]

Sounds a good session

 

 

[faulksy]

just come back from a awsome night myself, with my wife. report tomorrow and pics

[Nik271]

Looks you had a very  good night, @Pixies!

You certainly got Iota Leo. I was looking at it it last night and I believe it is much easier than 1 Leo (Kappa Leonis).

The close secondary of Iota is actually at mag 6.7 and directly east of the primary, just as you observed it. I also got it easily in my7 inch  Mak. What makes it easier is the smaller magnitude difference than Kappa.

Stelle Doppie lists another companion (C) at mag 11 but that is at huge 332'' separation.

Kappa Leo is much harder, last night I spent 30 mins looking at it carefully to make sure and only 20% of the time I saw the faint companion, it appeared SSW about 2'' from the primary , i.e. 7 o'clock position with mirror diagonal. I had a bit of haze, so perhaps this will pop out easier in transparent sky.

We appear to be heading to a period of clear still nights, fingers crossed

 

[Stu]

Nice report @Pixies, you definitely made the most of the clear sky despite the iffy conditions. Your description suggests that you did get Iota Leonis, nice one.

[Mr Spock]

Sounds like a great night - and a nice write up too.

0.62" is a tough challenge. When I had the C9.25 I did manage 0.7" once. It was a nice clean split though and often wondered just how tight it could go.

[Pixies]

1 hour ago, Nik271 said:

Looks you had a very  good night, @Pixies!

You certainly got Iota Leo. I was looking at it it last night and I believe it is much easier than 1 Leo (Kappa Leonis).

The close secondary of Iota is actually at mag 6.7 and directly east of the primary, just as you observed it. I also got it easily in my7 inch  Mak. What makes it easier is the smaller magnitude difference than Kappa.

Stelle Doppie lists another companion (C) at mag 11 but that is at huge 332'' separation.

Kappa Leo is much harder, last night I spent 30 mins looking at it carefully to make sure and only 20% of the time I saw the faint companion, it appeared SSW about 2'' from the primary , i.e. 7 o'clock position with mirror diagonal. I had a bit of haze, so perhaps this will pop out easier in transparent sky.

We appear to be heading to a period of clear still nights, fingers crossed

 

Thanks, Yep - further reading shows the magnitudes at 4.1 and 6.7 (2.3 arcseconds). SkySafari has the bad info - it says mags 4 and 11 at 2.3 arcseconds. That makes much more sense. I should have trusted my eyes and not what I read.

Edited April 4, 2021 by Pixies

[wookie1965]

Great haul I've already got my list ready but unfortunately looks like cloud tonight. 

[Pixies]

 

14 hours ago, Nik271 said:

Kappa Leo is much harder, last night I spent 30 mins looking at it carefully to make sure and only 20% of the time I saw the faint companion, it appeared SSW about 2'' from the primary , i.e. 7 o'clock position with mirror diagonal. I had a bit of haze, so perhaps this will pop out easier in transparent sky.

I've never really gotten my head around the angular positions, esp in a reflector. So today was a school day and I did some research on it, mainly from a few websites on measuring double-stars. So now I get it and as you said: Kappa Leonis' secondary is SSW of the primary (211 deg). I later had a look in Turn Left at Orion and they have a diagram in there!

Anyway, what I thought might have been the secondary flitting in and out of visibility was in the correct position, after all.