Pulsars in the Classroom: Presenter Stephen Broderick "Let's do real world mathematics" The "Pulsar" project is designed to engage students in scientific projects that will give them a positive attitude towards science and mathematics, and appreciation of how maths is applied in the real world. PULSE@Parkes allows students to directly control Parkes radio telescope over the Internet and use it to do real science. It is the only program of its kind in the world.

1. Australian Telescope National Facility
Marsfield, Sydney

5. Current projects ASKAP

6. International SKA (Square Kilometre Array)

7. How high would a stack of 15 million ipods be?
What area would all of the ipods cover when laid flat?

8. How high would a stack of 15 million ipods be?
15 000 000 x 0.5 cm ÷ 100 000 = 75 km
What area would all of the ipods cover when laid flat?
Area = 15 000 000 x 11 x 6 ÷ 1002 = 99 000 m2 (9.9 ha)

9. Australian Curriculum
Measurement and geometry
Solve problems involving surface
area and volume of right
pyramids, right cones, spheres
and related composite solids
(ACMMG271)

10. Statistics and probability
Use scatter plots to investigate and comment on
relationships between two continuous variables
(ACMSP251)

11. Number and algebra
Solve problems involving direct proportion. Explore the
relationship between the graphs and equations
corresponding to simple rate problems (ACMNA208)

12. Number and algebra
Use the definition of a logarithm to establish and
apply the laws of logarithms (ACMNA265)

19. SKA Will generate approximately
7 000 000 000 000 000 000 bytes of data in
the first week. (7 x 1018 bytes = 7 exobytes)
≈ All the words ever spoken by humanity

20. Average number of words ever spoken by
all of humanity (per day)
100 billion people (100 x 109) throughout
the ages.
Average number of words spoken per
person in one life time
7 × 1018
=
100 × 109
= 7 x 107
7 × 107
75 × 365
≈ 2600 words per day
Average per day =

21. Facts about Parkes, Pulsars
and Pulse@Parkes

23. Fact # 1
Since December 2007, over 1000 students from
interstate schools and overseas institutions have used the
Parkes Radio Telescope to collect data on pulsars for analysis.
Students have controlled the telescope via the internet to
observe several pulsars.
Frequently Asked Questions answered at:
http://outreach.atnf.csiro.au/education/pulseatparkes/teachers/teachers.html

24. Fact # 2
A pulsar is a rapidly rotating neutron star. Jets of electromagnetic
radiation stream from the pulsar and are observed as pulses of
radio waves because of this rotation.
The Parkes Radio telescope has been instrumental in discovering
nearly two-thirds of all known pulsars.

25. Fact # 3
What is a Pulsar?
• In 1934 Walter Baade and Fritz Zwicky proposed
the existence of a new type of star -neutron star
• In 1967 Jocelyn Bell discovered a pulsar(media
reported the discovery as little green men)

26. Fact # 4
Properties
• density of 1017 Kg/m-3
• thimbleful has a mass of 109 tonnes
• rotates once to several hundred times per
second
• acceleration due to gravity at surface of pulsar
is ~ 1012 m.s-2 (10 m.s-2 at Earth)
• escape velocity ~ 50% of the speed of light.

27. Fact # 5
Typical pulsar diameters are approximately 20 to 25 kilometres
with a mass roughly 1.4 times the mass of the Sun. The mean
density is approximately 6.7 x 1014 grams/cm3 which is
equivalent to a single sugar cube weighing as much as all of
humanity (approximately the weight of 7 billion people).

44. Fact # 6
PSR J1023+0038, is the fastest known millisecond pulsar. It
lies 4,000 light years away in the constellation Sextants
and spins at a rate of 592 times a second. After discovery in
2007 , the Parkes radio telescope was used to get the first
full orbit observations.
Astronomers have long thought that millisecond pulsars
are ordinary pulsars “spun up” with the help of an orbiting
companion star. The companion dumps matter onto the
pulsar, causing it to spin far faster.

45. Fact # 6 continued
Speed =
푑푖푠푡푎푛푐푒
푡푚푒
=
휋 푑
푡푖푚푒
=
휋 25
1
592
diameter = 25 km
= 46,496 km/sec (15% speed of light)

56. Fact # 5
The 64 metre Parkes radio telescope was built in 1961 and has
operated continuously for over 50 years. It is a world class
instrument at the forefront of radio astronomy due to continual
upgrades. It is now 10,000 times more sensitive
than when it was first built.

57. Fact # 6
A pulsar map was included on the Pioneer 10 and 11 probes
launched in 1972 and 1973 respectively. They show the
position of the Sun, relative to 14 pulsars, so that our position
in space can be calculated by extra-terrestrials that encounter
the probes.

58. Fact # 7
The pulsar catalogue has over 1,900 pulsars and can be accessed
electronically at the link below. Some pulsars have two different
designations (B and J). The designation B indicates 1950
coordinates which were used prior to 1993, whereas the J
designation is now used in 2000 coordinates . The J designation
also uses a more accurate declination. The example below
includes both designations for the same pulsar.
Before 1993
PSR B 1919+21
Pulsating source of radio
After 1993
PSR J 1919+2153
Location of the pulsar (right ascension , declination)
The complete pulsar catalogue can be found at:
http://www.atnf.csiro.au/research/pulsar/psrcat/

76. Fact # 8
The line graph indicates the number of
known pulsars from 1967 to 2011.
Discovery of the first pulsar
PSR B 1919+21 in July 1967
by Jocelyn Bell.

78. Fact # 9
The nearest millisecond pulsar (MSP)discovered in 1992 during
the Parkes 70 cm survey is approximately 510 light years away.
It is known as PSR J0437-4715 and it has a period of
5.757451831072007  0.000000000000008 milliseconds
It is the most stable natural clock in the whole universe.

79. Fact # 10
The Parkes radio telescope is so sensitive that a mobile phone
call from Pluto would be considered a really strong signal.

80. Australian and U.S. astronomers used
CSIRO's Parkes radio telescope to
measure the distortion of space-time
around the pulsar J0437-4715 and its
companion white dwarf.
In this pulsar system, the pulsar's radio
waves travel through the curved space-time
around its white dwarf
companion, and arrive on Earth a little
later than if they had travelled through
undistorted space-time. The effect,
called the Shapiro delay, was first
proposed in 1964 by Irwin I. Shapiro.
The data clearly showed the predicted
delay, making this the first test of
general relativity in which the geometry
of the system has been used to predict
a relativistic effect. This provided
another confirmation of Einstein's
general theory of relativity.
Fact # 11

81. Fact # 12
75% of all known pulsars have a period of less than a second.
In 1999, Astronomers using the Parkes radio
telescope found the pulsar J 2144-3933. This pulsar,
which spins only once every eight seconds, defied
existing theories on the upper limit for pulsar periods.

82. Fact # 13
Astronomers using the Parkes radio telescope in conjunction with the 76-metre Lovell
Telescope in England have discovered a possible diamond planet orbiting a newly detected
pulsar, PSR J1719-1438 located 4,000 light years away.

83. Fact # 14
The first confirmed exoplanets discovered several years before the
first detections of exoplanets around “normal” solar-like stars,
were found in orbit around a millisecond pulsar, PSR B1257+12.
These planets remained for many years the only Earth-mass objects
known outside our solar system. And one of them comparable to
that of our Moon in mass, is still today the smallest-mass object
known beyond the solar system.

85. Fact # 17
The magnetic axis of a pulsar aligned with the radio beam
is usually not aligned with the rotation axis.

86. Fact # 18
The hard disk drive of a computer rotates at high speed,
commonly 7,200 revolutions per minute or 120 revolutions per
second. The time to complete one revolution is 8.33
milliseconds. This is similar to the pulsar J1518+0204 which
has a period of 7.9 milliseconds and hence rotates slightly
quicker at 127 revolutions per second.
period = 8.33 milliseconds period = 7.9 milliseconds

87. Fact # 19
Millisecond pulsars (MSPs) have rotational periods in the
range from 1 to 30 milliseconds. They have been detected in
radio, x-ray and gamma ray portions of the electromagnetic
spectrum. One theory about their formation is that they begin
life as longer period pulsars but are spun up or "recycled"
through accretion of a companion star. The transfer of angular
momentum from the accretion of the companion can
theoretically increase the rotation rate of the pulsar to
hundreds of times a second, as is observed in millisecond
pulsars.

88. Fact # 20
Two main types of pulsars
Normal pulsars
• Are quite young, ˂ 107 years
• Periods from 0.03 – 10
seconds
• Mostly single (non-binary)
• Formed in supernova
• Magnetic field strength
approximately 1012 gauss
Millisecond pulsars
• Are very old, ˃ 109 years
• Periods from 1 – 30
milliseconds
• Mostly binary
• Accretion from
companion “spins up” the
neutron star to a
millisecond pulsar
• Magnetic field strength
between 108 -109 gauss

89. Fact # 21
The first binary pulsar was discovered by the Parkes radio
telescope in 2003. One of the pulsars has a period of 22
milliseconds and the other pulsar has a period of 2.7 seconds.
The orbital period for the binary pulsar system is 2.4 hours.
This is a highly relativistic binary system which is a laboratory
for testing Einstein’s general theory of relativity.