webspotting 24 - constellations

As published in the Dec 2011/Jan 2012 issue of SCOPE, the newsletter of the RASC Toronto Centre. Republished here with permission.

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During the brilliant, amazing, 7-night clear patch at the beginning of October, I spent every night out under the stars. I left the telescope on the porch so I could hit the ground running on each successive evening. It was like having a permanent observatory. And it was sweet.

I hadn't had a good run like that since February. But there was a little gotcha. In the winter, I can see more sky. Now, with leaves clinging to branches, in the treed High Park neighbourhood, there was relatively little of the celestial sphere to work with. My options would be limited to whatever I could hunt down in Cepheus, Cassiopeia, Lacerta, or Ursa Minor. But that was OK. I knew there was much to see. Lots I could learn. Up to this point, for example, I had only viewed one double star system in Cepheus. And I had no idea where the lizard was exactly—I didn't even know the main stars.

It was in this context, forced to view a small sliver of the sky from my small deck, that I realised I wanted constellation-specific lists. I have the wonderful Tirion SkyAtlas 2000 charts and the handy-dandy Pocket Sky Atlas. But I was suddenly interested in a different book, one I had only recently seen for the first time. A book a number of our members recently purchased together. It was Bryon Czarnik  who suggested, last year, Peter Birren's Objects in the Heavens and coordinated a group purchase at a reduced rate. It features constellation charts and for each there is a list of all the notable objects within. It would have been perfect.

Yes, I was planning to use my computers and software applications, like SkyTools and Stellarium, so I'd have no trouble finding and locating targets. But the experience would be different. Here, I wanted to view an object, and then, on a chart, see what was interesting and proximal, so I could do a little star hop, if that, maybe just slide a little, to the next object. Save time. Observe more.

All this got me wondering if there was a web site that had charts like this. And after some initial searches, I wasn't really pleased. Most of the promising searches dropped me into a web page that listed items of interest, but, invariably, the list was rather short, and there was never a chart or map. I gave up the search at the time, reverting to a hybrid approach with my current paper and electronic resources.

But I just gave it another go. And was very happy to find some useful charts, small, in colour, constellation specific, with objects identified, and—joy—completely free. Guess where? The official source! Yes, the organisation we all know and love, the International Astronomical Union. Surf into http://www.iau.org/public/constellations/ where you’ll find the constellations alphabetically arranged, with pronunciation tips, the genitive form, and then links to two versions of a chart, a GIF (small, for on-screen) and PDF (large, for printing).

Each simple chart emphasizes the constellation boundaries and lines. It shows if there are any variable stars, planetary nebula, bright diffuse nebula, globular clusters, open clusters, and galaxies in the area. Star magnitudes are visually expressed in the usual way with appropriately sized filled circles (down to 6). Bayer identifications (the Greek letters) are noted for stars with  some proper names shown. The equatorial coordinate lines appear as well. My only complaint is that double stars are not marked. Come on!

These charts may look a little familiar. The Sky and Telescope logo at the bottom right hints at who made them. Wish I had these in early October.