Inspired by sockpuppet's North Star writeup, dido's Precession of the equinoxes writeup (go and vote these guys up) and my own gyroscopic precession writeup.
This is the most precocious node on E2 and I claim my five pounds. See, it will be pretty useless for 12-14,000 years (depending who you ask). It probably won't be useful then either, as humans will undoubtedly have artificial data implants or something, so will not need this node, or (gulp) E2. Still, the knowledge has to come from somewhere. Perhaps E2 gets assimilated into the human knowledge base during that time. However, as usual, I digress.
At time of writing, Vega is not the north star. Polaris is, being within 1° of true north. However, because the earth's axes each trace a celestial circle, over a 25,800 year period the mantle of North Star gradually shifts between several stellar bodies. Presumably there are very irritating millennia during which there is not really a useful North Star at all because the earth's axis is too far from the current North Star and not close enough to the next one.
The North Star will officially be Polaris for about another five thousand years, after which it will be Alpha Cepheni. Seven thousand years after that, Vega will be closest to the centre of the northern sky and be the North Star. Of course it won't be close enough to true north to be a useful North Star for a few thousand years more, but rules are rules. Now, I coulda-shoulda noded How to locate Alpha Cepheni, the North Star. After all, it is the next one in the queue. But 'Vega' is a much cooler name for a star.
The name Vega is derived from Arabic for "falling eagle". I know this because a nerdy Sony dealer told me while I was mentally undressing one of their TVs. It is the brightest star in the constellation Lyra and the fifth brightest of all the stars in the sky. It will never precisely align with Earth's axis, but it comes very close.
So, how to locate Vega. You're lost, um, on the shiny stainless steel anti gravity skyway between Mega City Two and Humungous Conurbation Five. One way lies a life of opulence in your apartment, on a gigantic clothesline of luxury home units suspended between a replica of the towers of the former Golden Gate Bridge. The other way: disaster! Cleverly, your home is Northwards. Navigating your way there is easy! (cough) teleporter...
Vega is not the easiest star to locate since it doesn't line up with the most well-known constellations such as Orion (which will be in the southern sky by the time Vega is the North Star), Leo or Cancer (both of which will be very close to the horizon). However it is one of the brightest stars in the northern sky, which will help with locating it. There's a few methods (which I made up, so doubtless there's more) of zeroing in, with varying degrees of accuracy. Cassiopeia, Bootes and the Big Dipper/Plough/Great Bear/Ursa Major/Whatever the hell it's called today can all be roughly lined up with Vega in some way.
Ursa Major Constellation
* * * *
* 2 3
* Bootes Constellation
Note the numbered stars. Each is part of one method for finding Vega.
- Shedir and Caph in Cassiopeia line up to point roughly in the direction of Vega. These are the two stars that make up the longest edge of the 'W' of the constellation. Connect the two together, project the line in the direction the 3-starred end of the 'W' is pointing and you will eventually arrive near Vega.
- Likewise, Megrez and Phad in Ursa Major line up to point roughly towards Vega. These stars are adjacent to the 'handle' of the constellation. Connect the two together, project the line upwards and away from Ursa Major, if the shorter of the two longest sides of the rectangle it makes is the bottom. Again you will eventually arrive near Vega.
- This method is the most accurate, though it hinges on you being able to find Arcturus, which might be problematic in a built up area. However Arcturus is brighter than Vega, so hopefully can be found without too much trouble. If you trace the arc of The Plough's 'handle' past its end, it virtually leads you straight to Arcturus.
Now, Arcturus, Merek (aka Ursa Major Beta) and Vega link to form what is almost an equilateral triangle (though my ascii diagram might suggest otherwise). So, link Arcturus and Ursa Major Beta together and bisect the resulting line in the direction of the head of the Bootes kite constellation. It should soon become obvious which star Vega is, in the small fish-shaped constellation Lyra.
Et voila. Your friends will now doubtless be impressed with your 1337 forward planning sk1llz.
Um, of course, star constellations will be different in 14,000 years. Never let logic get in the way of a good node.
- My Celestial Planisphere jigsaw puzzle. How convenient.
- Various astronomy-oriented nodes/webpages, to get star names right. You'd be surprised how much searching it took.