Waid Observatory

Object: M109
Date: 03-25-2012 - Telescope: C14 - Camera: ST10-XME - Mount: MI-250
Location: Denton, TX - Exposure: Lum = 85 min.  R-G-B = 40-25-30 min.
Click on the image below to view at higher resolution.



M109 (NGC 3992) 1 - 2

Discovered by Pierre Méchain in 1781.

M109 (NGC 3992) is an example of a barred spiral galaxy.  As a point of interest, our own galaxy is also now classified as a barred spiral.  M109 is located in the Ursa Major galaxy group.  This group of galaxies is composed of 79 major galaxies.  M109’s distance from the Milky Way is approximately 55 million light years.  The galaxy is relatively bright and shines at a magnitude of about 9.5.  The inner portion of the galaxy seems to be relatively devoid of gas and therefore there is little new star formation in the bar section.  This probably accounts for the yellowish color of this region.  There is, however, enough gas in the outer spiral arms to support star formation. Dr. R. Gendler’s excellent description of the galaxy may be viewed here2.


Copyright Donald P. Waid