Doubles hunter

With my brand-spanking new Double Star Atlas, I can now really and truly have a go at hunting doubles!

Last night was the first in ages that was actually clear. There were some high wispy clouds at sunset that had J panicking, but they went away so we went outside. As well as my Atlas, the other exciting new thing I have is a Cat's Perch! J's been talking about getting a star chair for months, and he ended up ordering two of these - it's so much easier to focus and hold steady when you're sitting down, rather than standing. He'd constructed them last weekend, and sanded them yesterday, so they were ready for a test. And I loved mine: I was observing to the west, so I ended up having the scope very low down and the seat correspondingly so. I could have had it higher, but I think that would have been more annoying.

So, what did we see? I started off with Saturn, of course; and it was lovely. I could definitely see the shadow band under the rings, and I could just see one moon, which was either Rhea or Dione. I then swung around and decided to play around in Canis Major, to see what doubles I could find and whether the Atlas is going to work for me.

Firstly, I'm glad it's spiral-bound. The Atlas has 30 double-page maps, with constellations and doubles and some other features marked. Then, at the back, it has the list that the authors worked from, of which doubles to include: this has the magnitudes and separations of the respective stars. This is very, very useful when you think you've found the right star, but you're not sure you can see a companion, so you need to know whether they're only 8 arc-seconds apart and therefore unlikely to resolve under light-polluted skies (which happened to me), or whether the companion is TWO HUNDRED AND SIXTY FIVE arc-seconds away and therefore could be one of three faint stars you can see (I am annotating the list as I go, with ticks and dates of when observed. This one I also annotated with "srsly?!"). The one problem - and this is only a problem for me, not the book - is that they're in right-ascension order. This has to do with how the stars are mapped, and I am struggling to really get my head around it. (Dumb moment of the night: realising that I was treating the lines of right ascension and declination as if they were straight, rather than curved....) This is something that I will get used to over time. I presume.

Anyway. Canis Major. Start with Sirius; no luck splitting. Move up to Wezen: success! (At least, I presume so; that's the 265" split.) No luck with Adhara (7" split, so not that surprising). Then, on to some harder ones. There's a little group of three along the 'spine' of Canis, two of which are noted as binaries. I hazarded a guess at where they should be, looked in the scope... and didn't think I'd found it. Asked J for some help, tearing him away from his open-cluster hunting, showed him the map... and he found exactly the same thing. I looked at it a bit longer - checked the list at the back - and realised that actually, one was a triplet, and that's what I'd been confused by: the top star in my eyepiece had two very faint stars nearby, which was indeed my triplet! This was also helpful because I now have an idea of what 44" looks like. That was 17CMA; sadly couldn't split pi, so that will have to wait for another night. After that success, I attempted tau-CMA, which is in the open cluster NGC 2362 - which, I didn't realise, is J's favourite little one. And I found it, and I think I saw the double; at 85" separation, in a cluster, it's hard to be positive.

Unfortunately, I didn't have a great end to the night. There's another little group of three, between Sirius and Mirzam, that looked like they should be easy enough to find - two are bright-ish, and they're convenient between those two very bright stars. I got quite frustrated because I just couldn't find them. So J had a go, and swapped in our widest eye-piece. Turns out I was looking in exactly the right place... but I had totally underestimated just how wide the set was. This is another thing I will have to get used to judging. Anyway: I split v-1CMA and v-3CMA (although the latter doesn't appear to be in the master list, which is odd).

The other thing I have to get used to, and adjust my expectations for, is how many things I will manage to see in a night. At the moment, the answer is not that many. J has much more practice with observing, and reading charts, and is not handicapped with a monumentally unspatial brain like me - so he's always going to see more. It's also a lot easier to tell when you've hit a cluster, than when you've hit a double, so he can skip around more easily if he wants to. I think this is something I can deal with... eventually... and as I keep reminding myself, the sky actually will stay basically the same for my entire life. It's not like I'm running out of time to do this.

Last week's observing

We had a mighty fine time last week! A whole string of clear nights; we took the 'scope out the backyard and decided to work our way around Orion and Canis Major (and a couple of other fine things).

47 Tuc, and it really was beautiful.

In Orion, I checked out Rigel - which it turns out is a double star, and I could indeed see the very faint blue companion star. I also looked at the other three corners of Orion - Betelgeuse, which was really red, and I forget the names of the other two corners. Then there's Eta Orionis, which is really a triple but only the AB pair are visible, and even then very close: they look to be touching. The Trapezium, of course, is glorious; and the nebula of M42, even from the light-polluted backyard, is always a happy-Alex-making sight.

I enjoyed looking around Canis Major. Of course, there's Sirius - almost bright enough to be blinding in the scope. The delightful H3945 is an orange and blue double, pretty widely spaced apart. But even more awesome - and perhaps my new favourite object - is Beta 324: two pairs of doubles, perpendicular to each other. They just look amazing. Then there's M41, an open cluster; c121, another cluster; NGC2362, a tight cluster with a single very bright star in the center (Tau Canis Majoris); and yet another open cluster in NGC2360.

Mars is particularly marvellous at the moment. It's still getting up a little too late for easy casual viewing, but it's getting there. It's far enough north that when we were out and looking, we had to drag Ptolemy through the entire house (the courtyard looks south) to check it out. But it was worth it: a great big red disc. Glorious.

I think that basically covers it. I was pretty out of it the first night, despite J's attempts at jollying me into it. The next few nights I got more into it, which was great.