Transcript TY Course Day 2 Friday Constellations v1

Core Theme 2: Constellations
 Use astrological star sign as a hook; constellation
identification; origin and history; myths and legends; observing
the night sky; identify stars of different types, names and
colours; investigate available astronomical resources and how
to find them.
 Task: Observing, drawing, make up new constellation patterns
and associated stories, compare with constellations in other
countries to encourage global awareness.
Star signs and Astrology
 So who doesn’t know their star sign?!
 How do you think they were set?
 Have a look at tonight's night sky image copied on your
desk today – can you see some of the signs of the
Zodiac?
For the purpose of determining the constellations in contact with the ecliptic, the constellation
boundaries as defined by the International Astronomical Union in 1930 are used. For example, the
Sun enters the IAU boundary of Aries on April 19. Needless to say, the IAU defined the constellation
boundaries without consideration of astrological purposes.
The dates the Sun passes through the 13 astronomical constellations of the ecliptic are listed below,
accurate to the year 2011. The dates will increment by one day every 70½ years, and already
several have changed. The corresponding tropical and sidereal dates are given as well.
History
 Astrology consists of a number of belief systems which
hold that there is a relationship between astronomical
phenomena and events in the human world.
 In the West, astrology most often consists of a system
of horoscopes that claim to explain aspects of a
person's personality and predict future events in their
life based on the positions of the sun, moon, and other
planetary objects at the time of their birth.
 Many cultures have attached importance to
astronomical events, and the Indians, Chinese, and
Mayans developed elaborate systems for predicting
terrestrial events from celestial observations.
We are looking at Constellations in an
astronomical context!
 In modern astronomy a constellation is an internationally
defined area of the celestial sphere. There are 88 standard
constellations recognised by the International Astronomical
Union (IAU) since 1922.
 The majority go back to the original 48 constellations
defined by Ptolemy in the 2nd century. The remaining were
defined in the 17th and 18th century, the most recent found in
the southern sky.
 There are also numerous historical constellations not
recognised by the IAU, or constellations from regional
traditions of astrology or astronomy such as Chinese, Hindu
and Aboriginal.
http://www.iau.org/public/constellations/
Identification
We will look at 4 constellations here:
 Ursa Major
 Orion
 Pegasus
 Taurus
 Can you spot all four on your night sky map?
 To observe we must first become familiar, so we can
use heavens-above.com website, Stellarium
programme, a planisphere, viewer etc.
 When we get a clear night sky, wrap up warm, go to a
dark location and allow your eyes to become darkadjusted for at least 10min. Bring map/iPhone and
torch with red filter.
Ursa Major
Dominated by the Plough, the pointers point North to
Polaris. Roughly, this is the area the Hubble Deep
Field image was taken in. Ursa Major has many cultural
associations.
http://www.bbc.co.uk/programmes/p00cydkv
Orion
 Orion a winter constellation, beautiful. Betelgeuse is a massive
M-type red supergiant star nearing the end of its life. When it
explodes (probably not in our lifetime!) it will even be visible
during the day. Rigel is a B-type blue supergiant that is the sixth
brightest star in the night sky. . The Orion Nebula is in the
Hunter’s sword.
 http://www.bbc.co.uk/programmes/p00fd2qx
 Sirius, (the Dog Star, not shown here) following at Orion’s heel is
the brightest star in the night sky (a binary star).
Pegasus
 Pegasus is a constellation in the northern sky, named
after the winged horse Pegasus in Greek mythology. It
was one of the 48 constellations listed by the 2ndcentury astronomer Ptolemy.
 Stars of Pegasus – lets look at naming etc. here:
 α Peg (Markab), β Peg, and γ Peg, together with α
Andromedae (Alpheratz or Sirrah) form the large
asterism known as the Square of Pegasus.
 51 Pegasi, a star in this constellation, is the first Sunlike star known to have an extrasolar planet.
 IK Pegasi is the nearest supernova candidate.
 Spectroscopic analysis of HD 209458 b, an extrasolar
planet in this constellation has provided the first
evidence of atmospheric water vapor beyond the solar
system, while extrasolar planets orbiting the star HR
8799 also in Pegasus are the first to be directly imaged.
Magnitudes
Taurus – the Bull
 Has many interesting components. The brightest member
of this constellation is Aldebaran, an orange-hued, spectral
class K5 III giant star. Its name is from ‫ الدبران‬al-dabarān,
Arabic for 'the follower' (of the Pleiades). Bull’s eye.
The Pleiades (M45)
or Seven Sisters (Messier object 45), is an open star
cluster containing middle-aged hot B-type stars located in
the constellation of Taurus. It is among the nearest star
clusters to Earth and is the cluster most obvious to the
naked eye in the night sky.
Pleiades has several meanings in different cultures and
traditions. The cluster is dominated by hot blue and
extremely luminous stars that have formed within the last
100 million years – beautiful to look at!
Resources
 As mentioned earlier we can use some things to first become familiar with the night
sky: heavens-above.com website, Stellarium programme, a planisphere, viewer etc.
 Lets look at using these now briefly to find the night sky for tonight and perhaps what
time Orion rises?
 We can aslo use websites to get the children interested:
 BBC Sky at night
 http://www.bbc.co.uk/programmes/b006mk7h
 Orion
 http://www.bbc.co.uk/programmes/p00fd2qx
 Plough – cultural stories
 http://www.bbc.co.uk/programmes/p00cydkv
 Moore Marathon e.g. Objects 17-25
 http://www.bbc.co.uk/programmes/b006mk7h/clips
To finish my favourite story
 Dark cloud constellations
 The Great Rift, a series of dark patches in the Milky Way, is
more visible and striking in the southern hemisphere than in the
northern. It vividly stands out when conditions are otherwise so
dark that the Milky Way's central region “casts shadows on the
ground”. Some cultures have discerned shapes in these patches
and have given names to these "dark cloud constellations."
 Members of the Inca civilization identified various dark areas or
dark nebulae in the Milky Way as animals, and associated their
appearance with the seasonal rains. Australian Aboriginal
astronomy also describes dark cloud constellations, the most
famous being the "emu in the sky" whose head is formed by the
Coalsack.
 The "Emu in the sky," a constellation defined by dark
clouds rather than the stars. An IAU interpretation
would recognise Crux (the Southern Cross) above the
emu's head and Scorpius on the left. The head of the
emu is the Coalsack.
 Further information: Great Rift (astronomy)