Weymouth Astronomy

Deep Space Objects - September 2021

The Ring Nebula - M57

M57 can be found by star hopping towards Vega (brightest of the 3 stars which make the Summer Triangle), look south of Vega and approx. halfway between Vega and Albireo there are 2 bright stars Sheliak and Sulafat. Between these stars M57 can be found and is best observed June through to September.

Through a small telescope the ring looks like a small disk which is bright but hazy in contrast to the bright pinpoint stars surrounding it. By using averted vision you may be able to see it as what can best be described as a tiny smoke ring. Larger telescopes may be able to resolve irregular light variations from the ring.

This nebula is a cold cloud of gas (primarily hydrogen and helium) and is expanding away from a small hot central star which would require a large telescope (not less than 12" aperture) to sucessfully resolve. It is this star which provides the energy to make gas cloud glow.


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.