Milky Way

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As I mentioned in a previous post, there are a few ways to measure the distance of a star in our galaxy. Unfortunately when the Luminosity is unknown and it is too far away to use parallaxes method, we are stumped for ways to estimate the distance.

Once in a while though we get lucky and we have events that allow us to calculate distance in other ways. Circinus X-1 is one of these events. Circinus X-1 is an x-ray binary; an x-ray binary is a system of two stars where material from one companion is accreting on the neutron star, which in turns emits x-rays.

The Seven Wonders of the Milky Way are: The Sagittarius stream, a long, complex, structure made of stars that wrap in polar orbit around the Galaxy. It consists of tidally stripped stars from the Sagittarius Dwarf Elliptical Galaxy. The multi-planet planetary system around the millisecond pulsar PSR 1257+12.