Download April Skies

April Skies – 2009
Our installment next month will focus on the constellations Bootes, Corona
Borealis, Ursa Major and Ursa Minor. Hopefully we can also include links to
some astro images taken by our members. Thank you. Bob McGovern.
For the Naked Eye - For some fascinating mythologies and astronomy facts
simply Google the names found in the text below and check out the sky maps by
Sky & Telescope online at:
http://www.skyandtelescope.com/observing/skychart/ .
As you face south this month around the same time of day as you did last month,
you’ll notice how far those constellations have moved to the west. By 9 pm next
month, for example, the great hunter Orion will be standing nearly upright on the
NW horizon with his greater dog Canis Major while his neglected lesser dog,
Canis minor, is still stranded on the eastern side of the Milky Way. This will be
the last couple of months though to catch the bright winter stars located in 6
different constellations which form the asterism referred to as the winter hexagon
and described by Carol Latta the January newsletter. Not only does the Milky
Way pass through this asterism but so does the ecliptic – the plane of our solar
system – the track in which you will find the planets, moon and sun.
The Constellation Gemini the Twins – The constellation Gemini consists of two
bright stars from which seem to flow two strings of stars towards Orion. This
makes it easy to imagine them as twins of some sort. Look at the great stick
figure for them along with their placement in the winter hexagon on the website:
http://whassupinthemilkyway.blogspot.com/2008/03/winter-hexagon.html .
Although the Arabs considered them as two peacocks, the Egyptians as two
plants and the Hindus as twin Gods, we normally think of them as the twins
Castor and Pollux who the Roman armies believed led them into battle and on to
victory. The lower, brighter star, Pollux, in the head of the twin of the same name
and who was claimed to be exceptional in the handling of horses. The higher
star, Castor, marks the head of Castor the soldier. Mythology also links the twins
to the Argonauts who sailed with Jason to secure the Golden Fleece. There are
many great stories around this pair and I’m sure that their celestial father, Jupiter
is still bragging about their achievements!
I have to be careful here so as not to offend the Greeks. Their mythology has a
different twist on the story but is probably where the Roman myth originated. If
you think that the affairs and other behavior going on in Hollywood is alarming, or
maybe interesting (!), just read some Greek and Roman mythology! This is
where soap operas originated! An interesting link can be found at:
http://en.wikipedia.org/wiki/Castor_and_Pollux .
The Sun is in this constellation from the end of June till the end of July making
this area of the heavens unavailable for study for a few months either side of this
time. Castor is a beautiful double (a binary) star in a small telescope and a triple
in a larger, good quality telescope. It actually is a complex gravitationally bound
system of 6 stars. Also, check out the beautiful globular cluster M35 if you get
the chance in the next few weeks.
The Constellation Auriga the Charioteer - This constellation is outlined by a
pentagon of stars with Capella being the brightest (Capella is also part of the
winter hexagon asterism), the sixth brightest star in the sky, a multiple star
system and only 42 light years away. Mythology has it that Auriga was the son of
Vulcan and Minerva and was born with a deformity that made walking difficult.
To overcome this, Auriga invented the 4 horse chariot and was rewarded for this
by being placed in the heavens. Most drawings show a man in chariot holding a
female goat in his arms. Capella means “she goat”. Although I’ve personally
never seen a large man in a chariot holding a female goat, I once saw an elderly
gentleman driving a Volkswagen convertible with a gray Shetland pony on his lap
just outside of Syracuse – I thought that was rather strange but have since made
it a point to not dismiss out of hand something that others may have witnessed.
Although it’s difficult to imagine the figure of Auriga with his goat or a guy with the
pony, outlined by this star pattern, it is a beautiful constellation and worthy of
your attention. This area is a great place to scan with a telescope because a
number of beautiful globular and open star clusters are found there.
The Constellation Leo the Lion – Now here is a constellation that really does
look like what’s it’s supposed to be. This constellation was recognized and
worshiped as a lion by the ancient Egyptians as the sun was in this part of the
sky at the time of year when the Nile River flooded. Indians also imagined a lion
in this star pattern. Seeing this constellation is a sure indication that spring has
arrived! Face south and look high in the sky. Imagine the animal lying down with
his head facing to the right (west) and in the shape of a reverse question mark
(or some describe the shape as that of a sickle) with the bright star Regulus
(Latin for “prince” or “little king”) in the heart of the beast. To the left (east) locate
a triangle of stars outlining the hind quarters with the star Denebola (“tail of the
lion”) at the end of Leo’s tail. The plane of the ecliptic* runs almost through
Regulus so you may often be confused with another “star” in the area. This year
the planet Saturn is located in Leo, somewhat below a line drawn between
Regulus and Denebola. Planets don’t seem to “twinkle” like stars do because
they are not point sources of light as the more distant stars are and thus are not
affected by the continuous minor changes in our atmosphere. Don’t expect to
find Saturn there forever as in continues to move against the background stars in
its 29 year trip around the sun. A beautiful telescopic double star is Algeiba
located in the “sickle” just above and to the left of Regulus.
 The ecliptic is often referred to as the zodiac meaning “animal circle”. Of
the 12 constellations, or signs, defining the zodiac, 11 are of the animal
kingdom. The Romans considered Libra the scales to be the balance of
Aestraea, the goddess of justice. The Greeks interpreted these stars to
be the outstretched claws of Scorpio the scorpion.
The Constellation Ursa Major – We’ll discuss this constellation and the
asterism located within it, the “”big dipper or “drinking gourd”, next month. If you
wonder why spring is the wettest season of the year, just face north and locate
the inverted big dipper spilling its contents all over us and it’s not just here in
Rochester! The “drinking gourd” song and how it relates to the underground
railroad and Rochester is described at: http://www.followthedrinkinggourd.org .
The more prominent Planets –
Venus: Venus has been dazzling in the western sky all through February
and March as our “evening star”. By mid April, however, it will have raced
between us and the sun and is now our “morning star” rising in the east as a
crescent a half hour or so before sunrise. The most interesting views of Venus
are the illumination phases it goes through similar to those of our moon. Unlike
the phases of the moon though, Venus is brighter in the crescent phase than it is
in the full phase. Check out why this is so by visiting the website:
http://www.souledout.org/nightsky/venusphases/venusphases.html
Saturn – This planet will continue to be in a prime location in Leo for the next
couple of months with its ring system tipped nearly edge on. Gary Opitz has
called our attention to two occasions when we will have a chance to see the
shadow of its largest satellite, Titan, pass across Saturn’s disc. “The 1st one is
on April 13th (Monday morning) beginning at 3:22am EDT and Saturn sets
before the transit ends. The 2nd one is on April 29th (Wednesday morning)
beginning at 2:22am EDT and ends at 7:16am”. Video imaging time!
Moon - The moon has played an important part in determining many holiday and
festival dates for hundreds of years. The date for Easter can still be determined
as being the first Sunday after the first full Moon after the first day of spring (the
vernal equinox). This year the first day of spring was March 20th followed by the
first full Moon on April 9th. The first Sunday will then be Easter on April 12 th .
This method gives rise to the wide range of dates on which Easter can fall.
Each full moon throughout the year is given a name and the full Moon occurring
on April 9th has the following names as taken from the Farmers’ Almanac: “Full
Pink Moon - This name came from herb moss pink, or wild ground phlox, which is one
of the earliest widespread flowers of the spring. Other names for this month's celestial
body include the Full Sprouting Grass Moon, the Egg Moon, and among coastal tribes
the Full Fish Moon, because this was the time that the shad swam upstream to spawn”.