Deep Space Objects - August 2019
M81 and M82 Galaxies
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.
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 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.
|Weymouth Astronomy Estab 2006|