Andromeda Stap Map

 In ancient Greek mythology Andromeda represents the chained maiden, daughter of King Cepheus and Queen Cassiopeia. Andromeda chained to an overhanging rock, was rescued from Cetus the Whale by Perseus, riding on the winged steed Pegasus. Perseus was given Andromeda’s hand in marriage as reward for rescuing her from death.

On the rescue of Andromeda, Lewis Morris wrote: “On the hills a shout of joy, and on the rocks the ring of mail; And while the hungry serpent’s gloating eyes, Were fixed on me, a knight in casque of gold, And blazing shield, who with his flashing blade Fell on the monster.  Long the conflict raged, Till all the rocks were red with blood and slime, And yet my champion from those horrible jaws, And dreadful coils was scathless.”

The large constellation covers 722 square degrees in our Northern sky. To locate Andromeda first find the Great Square of Pegasus. Alpha α Andromedae (Alpheratz) the Head of the Chained Maiden marks the north-eastern corner of the square.  From here a few of the brighter stars in the constellation forms two irregular lines of stars towards the northeast.

Delta δ, a mag. 3.3 orange giant marks the left shoulder. Then following down from here the very brilliant orange giant of 2.1 mag. Beta β (Mirach) marks Andromeda’s left hip.

Further to the north-east the triplet Gamma γ (Almach) marks the left foot. Gamma can be split into a orange/blue pair of 2.3/4.8 magnitude ten seconds apart with a small telescope. The third star of 6th magnitude,  near the fainter of the pair will be close enough to us on it’s 61 year orbit in the year 2013 to be observed with amateur telescopes.

There are three open clusters in the constellation, the only one to observe in your telescope is NGC 752. It is a cluster of 60 scattered stars about 5 degrees south of Gamma. It is visible with binoculars and is easy to resolve with small telescopes – use a large field and low magnification, it is about 45’ across.

There are four known planetary nebulae…NGC 7662 also know as the Blue Snowball is the only one effectively seen in our telescopes.  It is easy to observe with a small telescope…at low power it appears as a 9th magnitude bluish star, with higher power of 100x it is a more slightly elliptical blue disk. The central star is too difficult to be resolved.

Andromeda is best known for the twin galaxy of our Milky Way, The Great Andromeda  Spiral Galaxy, M31 (NGC 224) which spans 3 degrees (nearly 6 moon diameters) on a very good night. It contains ~ 300 billions suns spread across 130,000 ly. It is 2.3 million ly away, one of the farthest objects visible to the naked eye.

When observing M31 look for the dark dust lane which runs along its north-western edge. Also look for the companion dwarf galaxies M32 (NGC221) and M110 (NGC 205). They may be visible as tiny, faint glows. M32 may be visible ½ degree south and slightly east of M31’s core as a fuzzy 8th magnitude glow it should be seen with a 75mm telescope. The larger, M110 is 1 degree north-west of M31 and more difficult to see. It is also suggested they may be visible with binoculars, I could not locate them with my 78mm scope or binoculars on a reasonably good viewing night.

To the naked eye M31 was easy to locate with my 7×50 binoculars by locating the bright orange supergiant Beta Andromedae and drawing a line six degrees to the north-west along the Maiden’s belt. It appeared as an oblong fuzzy ball.  Once locating it with binoculars I could see a faint blur with my naked eye.  With my 78mm telescope at 37x with a 17mm eyepiece it appeared as an irregular shaped fuzzy streak.  I then tried the 8mm Radian at 79x and 158x (with 2x Barlow) which made focusing more difficult and details of the galaxy were still not clear.  I could not see the companion galaxies M32 or M110.  Maybe we will have more luck at our up coming viewing night.

On my recent visit to the Northern Hemisphere Andromeda was much more impressive high in the eastern sky. M31 was very easy to locate with the naked eye and was brilliant with binoculars.  Observing with the 10” Newtonian on a Dobsonian mount I preferred to used low magnification of 47x with a 27mm eyepiece.  The whole galaxy was visible and the dark dust lane quite obvious on a clear night. It is a spectacular sight to observe all three galaxies in one field of  view, although the companion galaxies were only a small circular glow. I also observed M110 and M32 at 70x and 150x magnification to get a closer look.

Although Andromeda is more a Northern Hemisphere constellation it is worthwhile observing and exploring here in the South.

The most distant object easily visible to the unaided eye is M31, the great Andromeda Galaxy some two and a half million light-years away. But without a telescope, even this immense spiral galaxy – spanning over 200,000 light years – appears as a faint, nebulous cloud in the constellation Andromeda. In contrast, a bright yellow nucleus, dark winding dust lanes, gorgeous blue spiral arms and star clusters are recorded in this stunning telescopic digital mosaic. While even casual skygazers are now inspired by the knowledge that there are many distant galaxies like M31, astronomers seriously debated this fundamental concept less than 90 years ago. Were these “spiral nebulae” simply outlying components of our own Milky Way Galaxy or were they instead “island universes” — distant systems of stars comparable to the Milky Way itself? This question was central to the famous Shapley-Curtis debate of 1920, which was later resolved by observations of M31 in favor of Andromeda, island universe.

http://apod.nasa.gov/apod/ap080124.html Andromeda Galaxy

The Blue Snowball is a planetary nebula – and in 5 billion years the Sun will throw off its outer layers and go through a planetary nebula phase. A star can appear “normal” only so long as there are sufficient nuclear reactions in its core. Soon thereafter, gravity will win out and compress the stellar core to higher temperatures. Eventually the core becomes a white dwarf. These high temperatures somehow cause the expulsion of star’s outer layers, creating a planetary nebula such as the Blue Snowball pictured above. Although the Blue Snowball, also known as NGC 7662, does appear blue, the above picture’s colors are not real and were chosen to highlight the emission of certain ions in the nebula. Many things are still not known about planetary nebula, including details of the physical mechanism that creates the nebula, and the reason for fast knots of gas in the outer regions known as fliers.

http://apod.nasa.gov/apod/ap961121.html

m110