Radio Astronomy: An Informal Talk

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Radio AstronomyAn Informal Talk

• Presented to the
• Society of Physics Students
• Northern Virginia Community College
• 19 November
• by
• Prof. Harold Geller, GMU

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What Ill talk about

• Telescopes
• Electromagnetic waves
• Radioastronomy basics
• NRAO at Green Bank, West Virginia
• Small Radio Telescope at George Mason University

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What does a telescope do?

• Collect electromagnetic waves
• Collecting ability proportional to the square of
  the diameter of the objective
• Resolve electromagnetic sources
• Related to the atmosphere, wavelength and
  curvature of the objective
• Magnify surfaces of planets and the Moon
• Magnification only of Moon, Sun and planets

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Looking Beyond the Eyes
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Optical Telescopes
Reflector
Refractor
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Different Views of Sun
Sun in Hydrogen-alpha
Sun in X-ray
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Radio Astronomy Basics
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A Little More Detail
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Janskys Original Radiotelescope
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Grote Rebers Telescope
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170 foot Diameter Radio-telescope at Green Bank,
WV
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The 100-meter Green Bank Telescope
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Even Bigger than you Think
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Jupiter in Radio
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Saturn in Radio
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3C296 Radio/Optical Composite
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A Vision for George Mason (based upon Univ.
Indianapolis)
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Small Radio Telescope Justification

• Radio science observations in the L-band
• L-band lies in the 1400-1427 MHz region of the
  electromagnetic spectrum
• detection of what astronomers call the 21-cm line
  of hydrogen
• this is a portion of the hydrogen spectrum, in
  the radio region of the electromagnetic spectrum,
  which is generated by the neutral hydrogen clouds
  in the interstellar medium

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Small Radio Telescope Justification

• Observations in C-band, which is 4313-4338 MHz
  and 3788-3813 MHz
• Radio science observations in the C-band allow
  for the radio emission examination of the moon,
  which acts as a body at a temperature of 200 K.
• Students will be able to scan the moon, and
  detect the estimated 6000 joules of energy from
  the lunar surface.

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GMU SRT Background

• Funding
• National Science Foundation
• education portion of grant won by Dr. Rita
  Sambruna
• Order History
• ordered first week of June 2002
• stated 12 week delivery time
• received 15 October 2002
• damaged antenna

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GMU SRT Background Part II

• Order History
• boxes damaged
• FedEx insurance inspector called and visited to
  assess damage - refused claim
• replacement parts to be shipped by vendor
• Base assembled on roof
• 1 November 2002
• Remaining electronics and replacement antenna
  parts received 30 January 2003

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Did You Say Fragile?
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Picking Up the Pieces on the Roof
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Whistle While You Work
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Tolerance
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Cleanup On The Roof
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The Base Of SRT
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Servo Motors Attachment
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Servos with Ring Assembly
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Dish/Receiver Assembly
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Readying for Final Mechanical Assembly
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From Mechanical to Electrical
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Assembled and Ready to Test
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Sample Data
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Even Smaller - Radio Jove
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Small Radio Science Demonstration Projects

• Undergraduate research
• Steve Richardson
• web site built with some results from data
  acquired using U of Indianapolis
• http//physics.gmu.edu/arichar6/radio/index.html
• prepared presentation for GMU innovations fair
• prepared presentation for CPAC meeting at
  Bucknell University

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Really Smoothing
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Playing With The Data
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A Potpourri Of Color
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Family Portrait (2001 conference)
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Radio Astronomy Observatory at George Mason
University
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Looking To The Future
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Future GMU Observatory
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OnLine References

• http//www.aoc.nrao.edu/intro/image.index.html
• http//www.aoc.nrao.edu/intro/faq.html
• http//donald.phast.umass.edu/fcrao/education/rep
  ort1.html
• http//www.haystack.mit.edu/
• http//www.jpl.nasa.gov/radioastronomy/
• http//www.bambi.net/sara.html
• http//radiojove.gsfc.nasa.gov/

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Book References

• Radio Astronomy by John D. Kraus
• An Introduction to Radio Astronomy by Bernard
  Burke
• The Amateur Radio Astronomers Handbook by John
  Potter Shields
• Radio Astronomy for the Amateur by David
  Heiserman
• Radio Astronomy (Above and Beyond) by Adele
  Richardson

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Many Thanks

• Rita Sambruna (GMU)
• Maria Dworzecka (GMU)
• Justin Brown (GMU)
• Dan Thomas (GMU)
• Kathy Santiago (NVCC)
• John Avellone
• Christopher Helm
• National Science Foundation (NSF)
• MIT Haystack Observatory