Sunday 11 November 2012

Looking at Stars

One of the reasons for buying my new mirror lens was to photograph stars and planets.  With a tripod, a remote shutter release and a bit of patience, this can be done manually.  To test out the lens, I pointed it into the constellation of Taurus, to the Pleiades Star Cluster.
This cluster of stars is known as the seven sisters, though there are 9 clearly visible stars within a very large interstellar gas field.  It is now known that there are over 1000 objects in this star cluster, which is relatively close to our possition in space.
The main stars are clearly identifiable in this image.  Asterope is a binary star with its twin, Sterope.  In some texts, this star cluster is called the Maia Nebula, though it is not strictly a nebula.  This star cluster is about 120 parsecs distant from Earth.

1 parsec = 30,856,775,814,671,900 meters, which is about 19,173,510 million miles or 3.62 light year. This is 206,265 astronomical units where an astronomical unit is the mean distance between the sun and the earth.

This places the Pleiades at 434 light years distant.  This distance can be estimated as the parallax variation between the positions of the stars varies slightly from earth as our planet orbits the Sun.

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