March 13, 2008

Lynx

In the dark region of the sky between the twins of Gemini (Castor and Pollux) and the pointer stars of the Big Dipper (Dubhe and Merak), we find the constellation Lynx. This area of the sky was organized into a constellation by Johannes Hevelius, a Polish Astronomer. The name perhaps comes from the fact the most of the stars in it are so faint you would need the eyes of a Lynx to see them.

The brightest star in Lynx is 3rd magnitude Alpha Lyncis, which does not have a proper name. It is a nearly identical match for the only named star in the constellation, 4th magnitude Alsciaukat. The only real difference between them is that Alpha Lyncis is only about half the distance of Alsciaukat. Both are giant-class stars, a little cooler than our Sun and about 700 times more luminous and about twice as massive compared to our Sun. The only other moderately bright star of note is HR 3579, a double star only about 50 light years away consisting of two stars nearly identical to our own Sun.

There are a few deep sky objects of note here, and I'll start with the spiral galaxy NGC 2683, about a quarter of the way along a line connecting Alpha Lyncis with the bright star Pollux in Gemini. This edge-on galaxy is about eight times further from us than the great spiral in Andromeda. In the image, you can easily see the red-orange core of the galaxy compared to the blue spiral arms, and this difference is even more pronounced because the light from the core has to come to us through that disk of gas and dust.

Back in the direction of Alpha Lyncis, going about halfway back and then South a little bit is the faint but remarkable spiral galaxy NGC 2770. This rather faint galaxy is 90 million light years away, nearly 50 times more distant than Andromeda, and its claim to fame is that it has hosted three supernova events in the past ten years. Most spiral galaxies average about one per century. One of these supernovae appeared similar to a low energy Gamma-Ray Burster, a long story for another time.

Next up is an object within our own galaxy (sort of), the globular cluster known both as NGC 2419 and as the Intergalactic Wanderer. This cluster has an enormously high proper motion, and its large, elliptical orbit takes it so far from the center of the Milky Way galaxy that it takes about 3 billion years to complete one orbit. It gets further away from us than the Magellanic Clouds at times. Right now, this cluster is "only" about 300,000 light years away in a direction opposite that of the center of our galaxy (which is more toward the constellation Sagittarius), so it is pretty faint despite being the 4th brightest cluster (intrinsically) in the galaxy. You can find it about 7 degrees North of Castor.

Further North, about 2 degrees south of Muscida, the snout of the great bear of Ursa Major, we find the lenticular galaxy NGC 2549. This is a type of galaxy that bridges the gap between spiral and elliptical types, having some of the properties of both. Finally, over near the Western edge of Lynx, about 9 degrees North of Menkalinan in Auriga, we find the planetary nebula PK 164 +31.1. Not a very fancy name, this comes from a catalog of planetary nebulae compiled by the Astronomers Perek and Kohoutek. The numbers are indicative of the right ascension and declination of this object. Notice how thin the gas is in this nebulae. You can see distant background galaxies looking right through the nebula.

Posted by Observer at March 13, 2008 09:05 AM
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