APOD 2.1

For this week's APOD, I chose to write about the picture called Mirach's Ghost, uploaded on October 28, 2010.  It is a picture of the Mirach Ghost galaxy, containing the bright star Mirach in the center.


Mirach's ghost is a faint and fuzzy galaxy, and it can be classified by the name NGC 404.  NGC 404 was discovered by William Herschel in 1784.  It is a dwarf lenticular galaxy in the constellation of Andromeda.  Mirach's Ghost a spheroidal galaxy that has a few luminous young stars, with a high proportion of red giants.  A red giant star is a luminous giant star in the late phase of stellar evolution.  The star Mirach, centered in this star field, is classified as a red giant.  Mirach is about 200 light years away from us.  The star is cooler than the sun, but it is much brighter than our own parent star.  Just above and to the right of Mirach in the picture, one can find Mirach's Ghost, appearing to be about 10 million light years away.  Usually, telescopic views tend to have glare and diffraction spikes, which are lines radiating from bright light sources in reflecting telescope images, and they usually tend to hide things lying near the Mirach Ghost galaxy. But, in this picture, NGC 404 can be clearly seen to the right and just above of the star Mirach.