Mississauga Astronomical Society

Twentieth Meeting

 Speaker’s Night

Day:                Friday, April 16, 2004

Speaker:     Doug Welch

Monitoring the Solar Terrestrial Environment from Your Basement

Dr. Doug Welch, Ph.D. from the Hamilton Amateur Astronomers, and Professor at the Department of Physics and Astronomy of McMaster University spoke about basement astrophysics: monitoring solar flares and the solar – terrestrial environment. Dr. Welch is also the Canadian Gemini scientist and a researcher for the MACHO project.  He has been an amateur astronomer since the age of 8, a member of the AAVSO and RASC. Doug indicated that difficulty amateurs have of combining a clear sky with time commitments and as a result spoke about the astophysics project of detecting solar flares and gamma rays and monitoring changes in earth’s magnetic field from a basement, regardless of weather.

Many things can be monitored with a computer 24 hours a day using very little equipment. The ionosphere with its changes from molecular to ionic species propagates radio waves. The distant radio station NAA at 24.0 kHz (wavelength 30 km) in Maine broadcasts at high power at low frequency and can be monitored for changes in signal strength., thus indicating solar and other events. The basic components of the setup are a loop antenna (can be made with 14-gauge house wire), pre-amp, rectification and a recorder (typically now a computer). Radio frequency interference is common especially with light dimmers, and less so with computer monitors and carbon monoxide detectors and vacuum cleaners. One solution could be to move the loop away from the house. Further improvements could be made by using a PIC microcontroller chip as interface and AID converter.

Doug showed examples of small C solar flares and less common big M flares. Flares produce x-rays that arrive in the ionosphere producing interference and allowing detection. In addition, large gamma rays can bring the nighttime ionosphere into the daytime range thus allowing their detection. 

Solar- terrestrial disturbances, which produce the aurora, are associated with changes in the magnetic field at the earth’s surface.  The onset of a large geomagnetic storm has a distinctive signature in the magnetic field changes. These can be detected and recorded using the Tekatch – Welch Magnetometer. Design goals, among others, aim for an E-W component of geomagnetic field with noise of +/- 1 nT, sampling at frequencies of 1 Hz or less, removal of temperature sensitivity, and digital transmission of sensor data. Doug showed images and diagrams of the circuit board designs and photos of the setup. The magnetometer is able to sense changes in the orientation of the magnetic field based on solar wind changes. Doug showed tracings of 1 minute variations of geomagnetic field changes that he had recorded. His design can be found at: http://crocus.physics.mcmaster.ca/Magnetometer/TW/index.html

He encouraged the audience to experiment with observation and recording of such events, and his presentation was well received by the M.A.S.

 Submitted by Chris Malicki, Secretary  Chris Malicki, Secretary                               back to M.A.S. meeting reports page
Mississauga Astronomical Society