Weymouth Astronomy

Deep Space Objects - February 2020

M81 and M82 Galaxies

M81 - Image courtesy of Rob Hodgkinson Within the constellation of Ursa Major lies this pair of galaxies. M81 (NGC3031, Bode's Galaxy) is a large magnitude 7 galaxy which has a bright core and is therefore easily observed with small instruments. Through a telescope M81 has an obvious oval shape whereas M82 (NGC 3034), also known as the Cigar Galaxy is thin and pencil shaped. On very dark and clear nights it may be possible when viewing through a larger telescope to observe a dark lane of dust across M82.

M82 - Image courtesy of Rob Hodgkinson M81 is spiral galaxy where larger telescopes may review spiral arms extending from the core. M82 is an irregular galaxy with no defined sprial arms but is full of irregular dust clouds and collections of stars. M82 is the smaller of the two but still contains tens of billions of stars. Both of these galaxies are best seen from January through to August.


The Andromeda Galaxy - M31

The Andromeda Galaxy is the largest of approx. 20 galaxies (including our own Milky Way galaxy) which make up the 'Local Group'. Latest observations by the Spitzer Space Telescope revealed that M31 contains one trillion stars, greatly exceeding the number of stars in our own galaxy. M31 is best seen from September through to Jaunary. You should easily spot M31 with binoculars and, if there is a dark sky, you can even see it with your unaided eye.

To locate M31, find the square of Pegasus. Start at the top left star of the square - Alpha Andromedae - and move two stars to the left and up a bit. Then turn 90 degrees to the right, move up to one resonably bright star and continue a similar distance again in the same direction. Or by following the "arrow" made by the three rightmost bright stars of Cassiopeia down to the lower right.


The Pleiades - M45

M45 - The Pleiades This open cluster is best viewed from October through to March. This collection of stars also known as the 'Seven Sisters' and can be found by locating Orion high above the southern horizon. To the right is a bright orange-red star (Aldebaran - eye of Taurus), use this star as a stepping stone to the star cluster. Six stars of this cluster are easily visible to the naked eye but as many as 18 can be seen without any optical equipment if the skies are very dark and away from light pollution. In many ways this cluster is best viewed with Binoculars or the finderscope.