Pulsars: Astronomical Clocks In The Sky

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PulsarsAstronomical Clocks In The Sky

• Team J
• Ashley Randall
• Ashton Butts
• Priscilla Garcia
• Jessica Wilkinson
• Olivia Arrington

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Introduction

• Pulsars are rapidly rotating neutron stars
• A neutron star is only ten kilometers in size
• They are created in a supernova explosion near
  the end of a stars life
• Pulsars spin at quick speeds ranging from
  milliseconds to seconds
• Single pulsars spin about once every second, and
  pulsars in binary systems spin thousands of times
  every second

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Purpose

• To learn how to calculate the rotation period of
  a pulsar
• To calculate the size of the pulsars orbit
• To calculate the luminosity of the pulsar

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Methods

• Used NASA observations collected with the Chandra
  X-ray telescope
• Used the ds9 computer program to analyze the
  observations

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Materials

• DS9 computer program written by NASA
• DS9 instruction handbook
• Textbook Horizons Exploring the Universe by
  Michael A. Seeds
• Lecture Notes Dr. M. Richards
• Chandra X-ray Telescope archives
  http//chandra.harvard.edu/
• NASA Chandra Education webpage
• http//chandra-ed.harvard.edu/activities.html

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Procedures

• Load the light curve data from the Chandra
  archives

• Light Curve how light from the pulsar changes
  with time

• We measured the period directly from the light
  curve
• Calculated the average period and standard
  deviation for the group.

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Procedures

• The power spectrum finds any patterns in the
  light curve
• We calculated the period from the frequency
  Period 1 .
• Frequency

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Results

• Objects studied Cen X-3, GK Per, Vela pulsar

GK Per
Cen X-3
Star size 6000 km Rotation period 350.87 sec
Star size 10 km Rotation period 4.807 sec
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Results

• When we expand the power spectrum for Cen X-3,
  the peak looks broad
• The light from the pulsar is blue-shifted and
  red-shifted because the pulsar is moving around
  another object
• Measure the spin period and orbital period of Cen
  X-3

Pulsar moving away from us
Pulsar moving towards us
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Results
Luminosity 4? distance2 x flux
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Conclusions/ Further Research

• Astronomical clocks are found in many places in
  the sky.
• We studied the light curves of three astronomical
  clocks and measured their properties.
• We calculated spin periods and confirmed that
  pulsars spin at very high speeds. They have
  periods from seconds to milliseconds.
• Future work

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Acknowledgements

• Eberly College Of Science
• Dr. Daniel Larson, Dean of Eberly College of
  Science
• Dr. Mercedes Richards
• Ms. Jody Markley
• Mrs. Annie Holmes
• Mr. Craig Keiser
• Ms. Joanne Nash
• UBMS Staff

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• Any Questions??