Download Cassiopeia Kelly Pearce

Cassiopeia
Kelly Pearce
Cassiopeia – General Information
When the night sky is viewed from Nanaimo, British Columbia, a number
of constellations and the asterisms associated with the objects within them are
apparent year round. One of these circumpolar constellations shines as a
distinct W, M or E shape in the Northern night. Cassiopeia is approximately
opposite the big dipper of the Earth’s current North Star, Polaris. Cassiopeia is
prominent in the Northern hemisphere year round but shines like a crown high in
the sky in the autumn months of October and November. Although Cassiopeia is
the proper name of the constellation, the common names associated with this
constellation are the W, M or E or the Ethiopian Queen, apparent in 5 bright stars
within this constellation. At 21:00h in Pacific Daylight Time on September 14th,
2010, Cassiopeia is visible from Nanaimo in the North East, approximately two
thirds of the way from the horizon to zenith, the point directly overhead (Starry
Night Enthusiast, 2010). For a detailed drawing of Cassiopeia, please see
Appendix 1A.
Starry Night Cassiopeia
Contained within the Cassiopeia, five bright stars form the recognizable
shape of a “W”. The shape is meant to represent the chair of Cassiopeia, the
Queen of Ancient Ethiopia but is typically identified as a letter: either “W”, “M” or
“E”. The shape also looks like a crown in the sky with the stars sparkling like
jewels. Another perception of Cassiopeia is a mountain, either in shape or
metaphor. In shape, the mountain forms two peaks with a definitive valley
between them. In metaphor, the shape represents the ups and downs of Queen
Cassiopeia’s life. Please see the drawn diagram, Appendix 1B.
Queen Cassiopeia in her Chair
Ancient History of Cassiopeia
Although the Ancient Greek civilization were not the first to map the sky,
most of the constellations that are described today are largely intertwined with
Ancient Greek Mythology. Cassiopeia was the Ancient Queen of Ethiopia and
Cepheus was her King (Raymo, 2001). Cassiopeia claimed that her daughter
was more beautiful than the sea nymphs, who complained to the sea-god
Poseidon (Ibid). Poseidon sent a sea monster, Cetus, to ravage Ethiopia (Ibid).
Cepheus protested the devesation of his country and agreed to sacrifice his own
daughter to the beast in exchange for the salvation of his people (Ibid). When
Andromeda was chained to a rock to be consumed by Cetus, Perseus and his
winged horse, Pegasus happened to be journeying back from slaying Medusa,
the feared woman that was so ugly, if you looked at her, you turned to stone
(Ibid). Perseus, who was carrying the head of Medusa, showed Cetus without
looking at it himself (Ibid). Cetus turned to stone and sank to the bottom of the
ocean, while Perseus removed Andromeda’s chains and became so smitten with
her beauty that he asked Cepheus for her hand in marriage (Ibid). The Ancient
Greek Gods then placed Cassiopeia, Cepheus, Andromeda, Perseus (and the
head of Medusa) and Pegasus in the stars within close proximity (Ibid).
Cassiopeia – The Asterism
The five bright stars that make up Cassiopeia include, from Left to Right:
Epsilon Cassiopeiae, Delta Cassiopeiae, Gamma Cassiopeiae, Alpha
Cassiopeiae, and Beta Cassiopeiae (Starry Night Enthusiast, 2010;
Astro.wise.edu, 2010).
Constellation Cassiopeia
Epsilon Cassiopeiae has a traditional name Segin and is blue-white in colour
(Stars.Astro.Illinois.edu, Segin, 2010). It forms the outer most left point of the W
and is the fifth brightest of all 5 stars. It is noticeably dimmer than the remaining
stars but definitively forms the one of the outermost points of the shape. The
next star to the right is Delta Cassiopeiae and is traditionally called Ksora or
Ruchbah, where the latter is derived from the Arabic word, meaning knee
(Stars.Astro.Illinois.edu, Ruchbah, 2010). Delta Cassiopeiae is blue in colour
and is the fourth brightest in the asterism (Ibid). Gamma Cassiopeiae is the
centre point of the “W” and is also blue-white in colour (Stars.Astro.Illinois.edu,
Gamma Cas, 2010). The intensity of Gamma Cassiopeiae varies due to the
unstable and eruptive nature of the object, as well as the existence of a disk that
forms around the object when spinning rapidly (Gater & Vamplew, 2010, p.88).
Gamma Cassiopeiae is so volatile that it fluctuates from being the brightest star
in the asterism, to being the third brightest and everywhere in between
(Stars.Astro.Illinois.edu, Gamma Cas, 2010). The next star over, Alpha
Cassiopeiae, is also called Shedar (Stars.Astro.Illinois.edu, Shedar, 2010). It is
the brightest star in the constellation Cassiopeia, when the extremely volatile
Gamma Cassiopeia is not outshining it (Ibid; Gater & Vamplew, 2010, p.88). The
furthest right star that makes the W in the constellation Cassiopeia is Beta
Cassiopeiae, also known as Caph or Tycho’s star (Stars.Astro.Illinois.edu, Caph,
2010). Beta Cassiopeiae is yellow-white in colour and is usually the second
brightest star in the constellation depending on Gamma Cassiopeiae’s state
(Ibid). The constellation Cassiopeiae is most distinguishable by the five
prominent stars that make up the asterism “W” in the night sky and are
documented in the table below (as viewed from left to right when asterism makes
a “W”).
Constellation Boundary
Traditional Name
Common Name
Brightness
Epsilon Cassiopeiae
Segin
5 Brightest
Delta Cassiopeiae
Ksora or Ruchbah
4 Brightest
Gamma Cassiopeiae
None
Alpha Cassiopeiae
Beta Cassiopeiae
Colour
th
Blue-white
th
Blue
3 Brightest (depending on state)
rd
Blue-White
Schedar
Brightest
Orange
Caph
2
nd
Brightest
Yellow-White
Deep Sky Objects in Cassiopeia
Aside from the asterism within Cassiopeiae, other notable objects exist
within the boundary of the constellation. These observable objects include both
New General Catalogue objects and Messier objects. New General Catalogue is
a catalogue of recorded deep sky objects and is referred to as NGC (SEDS, The
Messier Catalog, 2010). The first of these objects, NGC 457, is also called the
Skiing Cluster, the Owl Cluster or the ET cluster, depending on how you perceive
the cluster of stars (Starrynighteducation.com, 2010; Gater & Vamplew, 2010,
p.88). It is located near the edge of the constellation boundary, bordering on
Cepheus (Starry Night Enthusiast, 2010). NGC 457 is an open cluster, meaning
that the hundreds or even thousands of objects within it formed at the same time,
from the same nebulae (Gater & Vamplew, 2010, p.88). There is one object
within the NGC 457 that is not a part of the open cluster and is actually a red
giant that is approximately 6,700 light-years closer than the remaining cluster
group (Ibid). This red giant appears in the asterism as a noticeably red object, as
seen below in the unlabelled images. (Ibid).
The ET Cluster
NGC 457
Messier objects are also NGC objects but were labeled by a French
astronomer, Charles Messier, whom first listed the objects to avoid mistaking
them for comets (SEDS, The Messier Catalog, 2010). There are 110 listed
objects in the Messier catalogue (Ibid). Within the Constellation boundaries of
Cassiopeia, there are two Messier objects (Starry Night Enthusiast, 2010). The
first is M52 which is also called the Scorpion and visible through binoculars
(SEDS, M52, 2010). M52 is an open cluster containing several hundred stars
(Ibid). The brightest star in the cluster view is an orange star that is in the line of
sight between Earth and M52, but is not actually apart of the cluster (Ibid).
M52, The Scorpion
The second Messier object in the constellation of Cassiopeia is M103,
which has been variably measured to be between 9 and 25 million years in age
(SEDS, M103, 2010). M103 is one of the more remote clusters in the Messier
series measuring between about 8,000 and 9,500 light years away (Ibid). The
cluster is loose and is considered to contain varying amounts of objects, with the
average observed about 70 in total (Ibid). Within the field of view from Earth,
M103 appears to contain an object that is not part of the same nebula group
(Ibid). This object, called Struve 131 is a bright binary star that is the brightest in
the area, which leads to its inclusion in the Messier grouping (Ibid). For a
detailed drawing of M103, please see Appendix 1C.
M103
Another deep sky object within the Cassiopeia boundaries is known as
Cassiopeia A, Cas A or 3 Cassiopeiae and is the remnants of a massive star that
exploded as recently as 320 years ago (Chandra.Harvard.edu, 2010). Cas A is
considered a supernova, which occurs when a star has used up its nuclear fuel
and pressure builds contracting the material and increasing the temperature
(Ibid). As a result, the explosion of materials is sending debris in all directions at
an incredibly high speed (Ibid). This explosion involves materials such as iron,
sulfur and silicon creating vibrant colours and a whimsical shape (Ibid). Cas A
appears to be a ball of rainbow with prominent pinks, purples, blues, greens,
yellows and bright white lights that seem to shimmer like oil on water. The
gumball characteristics of Cas A mask the intense heat, pressure and explosions
that are taking place to form the beautiful object. For a detailed drawing of Cas
A, please see Appendix 1D.
Cassiopeia A
Conclusion – Cassiopeia
One of the most distinguishable features in the Northern night sky is the
lop-sided “W” or Cassiopeia, the Queen of Ethiopia. Cassiopeia contains an
asterism made up of 5 distinct and bright stars. It also contains deep sky objects
such as Messier, New General Catalogue and Supernova. Cassiopeia shines
the brightest in the autumn sky and sparkles like the jewels of a Queen’s crown.
The ancient story of Cassiopeia adds to the mystery, adventure and excitement
that encompasses the stars in the sky. The dominance of the constellation in the
Northern hemisphere allows for careful and plentiful observations of the pieces
that make up this well-known constellation.
Cassiopeia References
Astro.wise.edu, 2010. Cassiopeia. Retrieved on November 12, 2010 from
<http://www.astro.wisc.edu/~dolan/constellations/constellations/Cassiopeia.html>.
Chandra Press Room, 2010. Cassiopeia A fact sheet. Retrieved on November 28, 2010
from < http://chandra.harvard.edu/press/casfact.html>.
Gater, W. & Vamplew, A. (2010). The practical astronomer. DK Publishing: New York, New
York.
Raymo, C. (2001). An intimate look at the night sky. Greystone Books: Vancouver, British
Columbia.
Starry Night Enthusiast, 2010. Cassiopeia.
STARS, 2010. Caph. Retrieved on November 16, 2010 from
<http://stars.astro.illinois.edu/sow/caph.html>.
STARS, 2010. Gamma Cas. Retrieved on November 16, 2010 from
<http://stars.astro.illinois.edu/sow/gammacas.html>.
STARS, 2010. Ruchbah. Retrieved on November 16, 2010 from
<http://stars.astro.illinois.edu/sow/ruchbah.html>.
STARS, 2010. Segin. Retrieved on November 16, 2010 from
<http://stars.astro.illinois.edu/sow/Segin.html>.
SEDS, 2010. The Messier catalog. Retrieved on November 16, 2010 from <
http://messier.obspm.fr/>.
SEDS, 2010. Messier objects. Retrieved on November 16, 2010 from <
http://seds.org/messier/>.
SEDS, 2010. M52. Retrieved on November 16, 2010 from <
http://seds.org/messier/m/m052.html>.
SEDS, 2010. M103. Retrieved on November 16, 2010 from <
http://seds.org/messier/m/m103.html>.
SEDS, 2010. Star Clusters. Retrieved on November 16, 2010 from <
http://seds.org/messier/cluster.html>.
University of Wisconsin Astronomy Department, 2010. Cassiopeia. Retrieved on November
6, 2010 from <
http://www.astro.wisc.edu/~dolan/constellations/constellations/Cassiopeia.html >.
Cassiopeia Image References
Cassiopeia A. Retrieved on November 28, 2010 from
<http://cdn.wn.com/pd/f4/6f/6ab4f0c441e65d70f93e31bf779c_grande.jpg>
Cassiopeia Constellation, Title Page. Retrieved on November 28, 2010 from
<http://www.nasa.gov/multimedia/imagegallery/image_feature_1610.html>
Constellation Boundary. Retrieved on November 28, 2010 from
<http://www.starhopper.info/cassiopeia.htm>.
Constellation Cassiopeia. Retrieved on November 28, 2010 from
<http://www.derekscope.co.uk/wp-content/uploads/2010/05/Cassiop.jpg>.
The ET Cluster. Retrieved on November 16, 2010 from
<http://manalokos.com/astro/main.php?g2_itemId=206&g2_imageViewsIndex=1>.
M103. Retrieved on November 28, 2010 from < http://apod.nasa.gov/apod/ap010207.html>.
M52 The Scorpion. Retrieved on November 16, 2010 from
<http://farm3.static.flickr.com/2586/3884740645_5735367974.jpg>.
NGC 457. Retrieved on November 16, 2010 from
<http://www.nightskyinfo.com/archive/ngc457_open_cluster/ngc457.jpg>.
Queen Cassiopeia in her Chair. Retrieved on November 16, 2010 from
<http://images.cdn.fotopedia.com/flickr-2861163910-image.jpg>.
Starry Night Enthusiast 6, 2010. Starry night Cassiopeia.