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4. M31, Andromeda Galaxy
Notes: Two satellite galaxies of Andromeda are visible in the image: M110 on the upper left and M32 to the right. The detail in the inner nebula outside the core is good, and the core is less overexposed than in figure (1). Our polar alignment was fair at best, as we kept the alignment from October 21. The stars are closer to round than in images (1) and (2), and focus was improved by using the fine focus in Nebulosity. The short exposure times have the advantage of reducing smears caused by tracking error and poor polar alignment, but they also have drawbacks, one of which is a poor signal to noise ratio as evidenced by visible red grain if we try to magnify. In image (3), only a fraction (half?) of the disk is visible. Some of it is recaptured here by altering the file in Photoshop. Detail in the disk was brought out by selecting the entire disk region, putting it in its own layer, and stretching it. Some features of the disk can be seen more clearly in image (1). Zoom in/out with ⌘↑(+/-) (Mac), ctrl (+/-) (PC).