Saturday, August 25, 2012


This is an excellent time of year to locate the constellation Aquarius, rising above the eastern horizon in the hours after nightfall.

Aquarius is an important constellation, because he is in the zodiac (the band of constellations through which the ecliptic passes), and because of the phenomenon of precession (explained in many previous blog posts and in this video, as well as in the Mathisen Corollary book itself). However, Aquarius is not the easiest of constellations to find, because he is composed of very faint stars.

To locate Aquarius, it is perhaps easiest to start by locating the two great birds winging their way towards one another in the band of the Milky Way -- the Swan and the Eagle (discussed in this blog post, with diagrams for locating those two constellations).  You may want to start at the southern edge of the Milky Way, where the Galaxy rises like a silvery trail of smoke from between the constellations Scorpio and Sagittarius: if you follow the Milky Way upwards from the southern horizon you will encounter the Eagle first and then the Swan (these directions are oriented for observers in the northern hemisphere).

The diagram above shows the view to the east after sunset (depending on the time you are looking towards the east, depending on your latitude, and depending on the terrain features that make up the horizon to the east, the horizon may be as high as the lowest star of the Great Square of Pegasus, but as the hours of the night roll past, the stars shown here will continue to make their way higher and higher above the horizon).

Once you have located the Swan and the Eagle, you can use the three bright stars of the head of the Eagle as a pointer to direct you to the little zodiac constellation of Capricorn, the Goat.  The center star of those three bright stars of the Eagle's head is Altair, which is one of the three stars of the famous Summer Triangle (discussed in that blog post about Swan and Eagle linked above -- the other two stars in the Summer Triangle are Deneb in the Swan and Vega in the Lyre).  The other two stars on either side of Altair in the bright line of three stars in the Eagle's head are Tarazed and Alshain (discussed in this previous post).  These three stars in the Eagle are very distinctive and you should be able to find them quite reliably. 

The three stars in the Eagle point towards the little tail of the constellation Capricorn, the Goat.  It is also a little line of three stars, but not nearly as bright as the three in the Eagle, and only the top two of them are really easy to see -- the third is pretty faint.  Remember that there is also one star that forms one of the wingtips of the Eagle between those three stars of the Eagle's head and the tail of Capricorn.  The diagram below shows a dotted arrow from the head of the Eagle to the tail of the Goat:

From the tail of Capricorn, you can trace your way along the back of the Goat to his head, which has a sharp horn pointing right to Aquarius (pointing to one of his feet, in fact).  Below is a diagram of Capricorn, showing all the stars of that constellation, and connecting them after the manner suggested by H.A. Rey, who not only created the beloved Curious George stories but also proposed a more intuitive way to envision the constellations (the lines for the H.A. Rey outline are in red -- you can see some of the conventional lines in green, which connect the stars of the Goat in a completely unhelpful fashion to create an amorphous shape that looks nothing like a Goat):

The easiest stars in Capricorn to see at night are those stars of the tail (by far), and then the stars at the other end of him, at the end of his horn.  In the diagram above, I have added a label for his "Horn" and his "Tail."  The two upper stars of the Tail are the brightest, followed by the two stars at the end of his Horn (labeled with a lowercase delta and a lowercase gamma in the picture).  The thicker red lines indicate the parts of Capricorn that you can trace most easily, and they are enough to give the impression of the little Goat in the night sky.  Follow his Horn towards Aquarius.

On the other side of Aquarius, the Great Square of Pegasus is another good landmark.  In the picture above (the one above the picture dedicated to Capricorn) you can see a second arrow (on the left of the diagram) running diagonally through the Great Square to point towards the head of the constellation Aquarius.  These two night-time "landmarks" help bracket the location of Aquarius for you: to one side, there is the Great Square of Pegasus, with a diagonal that points towards his head, and to the other side there is the zodiac constellation of the Goat, whose little Tail you can find by way of the Eagle, and whose Horn points towards one of the feet of Aquarius.

Staring at this region of the sky, you can begin to trace out the shape of Aquarius, the Water-Bearer.  His head is diamond-shaped, but only three of the four stars that make up the diamond are even moderately bright -- the fourth is really hard to spot.  From his head, you can trace down his body to his "hip" joint and then to his two feet (the star at his hip and the star at the base of his diamond-shaped head are his brightest).

From that bright star at the base of his head, you can trace his arm down to his water vessel, which has two streams of water flowing from it in two distinctive streams.  At the bottom of each stream are three little stars curving away (you can see them in the above diagram, although the lines representing the streams of water coming out of the water vessel do not continue through those three little stars found at the base of each stream in the above diagram, for some reason).

Once you have located Aquarius, you can contemplate the fact that the celestial mechanics of precession are inexorably causing the heliacal rise of the stars on any given day of the year (such as each equinox and each solstice) by a single degree every 72 years.  

Because the constellations are twelve in number, this means that on average, a new constellation dominates the vernal equinox every 2,160 years, as the previous zodiac constellation is delayed enough to have its preceding constellation usurp its position on that important day.  For the past two millennia, the constellation Pisces has held that position on the March equinox, but as it is delayed by precession the constellation Aquarius will take over.   This is the meaning of the "end of the Age of Pisces" and the "dawning of the Age of Aquarius."  The exact year of that transition is debatable, as it depends on where you "draw the line" between the two zodiac constellations (there being some space between the constellations themselves -- so it is a question of "whose airspace" we are in, so to speak).

Nevertheless, Aquarius is the next constellation to take over, heralding a new precessional age.  Now you know how to find it in the sky (we're discussing it now, during the months when it is rising after sunset in the night sky, rather than during the months of the year in which it rises above the horizon just before the sunrise).

It is probably difficult to think about Aquarius without the music of The 5th Dimension coming to mind.  In fact, having their famous song running through your head may be extremely helpful when attempting to locate the stars of the constellation Aquarius.

Below are some images of what apparently will take place once the precessional transition is in full effect: