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DR ELIZABETH ALEXANDER: FIRST FEMALE RADIO ASTRONOMER? PowerPoint Presentation
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DR ELIZABETH ALEXANDER: FIRST FEMALE RADIO ASTRONOMER?

DR ELIZABETH ALEXANDER: FIRST FEMALE RADIO ASTRONOMER?

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DR ELIZABETH ALEXANDER: FIRST FEMALE RADIO ASTRONOMER?

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  1. DR ELIZABETH ALEXANDER: FIRST FEMALE RADIO ASTRONOMER? Wayne Orchiston Australia Telescope National Facility, and Anglo-Australian Observatory, PO Box 76, Epping, NSW 2121, Australia. Wayne.Orchiston@csiro.au

  2. 1. INTRODUCTION Jansky & Reber WWII radar Solar Detections • Hey (UK) • Reber; Southworth (US) • Alexander (NZ) • Germans (Denmark) • Slee (Australia)

  3. 2. FRANCES ELIZABETH SOMERVILLE ALEXANDER (neé CALDWELL) 1908 b. December 13 (Merton, Surrey, UK) 1909 India (Patna Science College) 1918 England 1931 Cambridge (Geology; Harkness Prize) 1934 Cambridge Ph.D. (Aymestry Limestone) 1935 Married Dr N.S. Alexander 1936 Singapore (Navy: radio direction-finding) 1942 New Zealand (+ William, Mary & Bernice) 1946 England 1947 Singapore (Raffles College > U Malaya) 1952 Nigeria (University College, Ibadan ) 1958 d. October 23 (Ibadan, Nigeria)

  4. 3. WARTIME IN N.Z. RDL (Op. Res. Section) • Radar developments • Whales & seagulls • ‘Canterbury Project’ • ‘Norfolk Island Effect’

  5. 4. THE ‘NORFOLK ISLAND EFFECT’ RNZAF 200 MHz COL radar units N.Z. + Norfolk Is

  6. Norfolk Island: 1945 March 27 – April 01Large increases in ‘radio noise’ recorded near sunrise & sunset“Rotation of the aerial showed noise fluctuations corresponding fairly closely to the radiation diagram of the aerial. At its maximum the noise reached saturation on the azimuth of the sun …” (Alexander, 1945a: 1).Elizabeth Alexander assigned to investigate the“Norfolk Island Effect”

  7. Monitoring: 1945 April 10 – 23Northern NZ + Norfolk Is #5 1 = Norfolk Island 2 = North Cape 3 = Whangaroa 4 = Maunganui Bluff 5 = Piha

  8. At Whangaroa microammeter inserted between the receiver output and diode limiter = immediate results. Combined observations enough to convince Alexander that “… the Norfolk Island effect was significant and was connected with radiation from the sun …”

  9. 1945 July-December: Air Force, Army & NavyRadars N.Z. + Norfolk Island Intense 200 MHz solar emission centred on October 5: “… violent surges of noise were observed at regular intervals. These surges were of momentary duration and sent the noise meter needle hard over.” (Alexander, 1945b). At Piha (#5) Yagi also tracked Sun; gain < radar “Noise signals from the direction of the sun were observed. The signals fluctuated rapidly but did not completely disappear until sunset.” (ibid.).

  10. Overall results, 1945

  11. End 1945/early 1946 radar stations & RDL closed: • E.A. to England + Singapore • Publication (new N.Z. journal):“The Sun’s radio energy.” Radio and Electronics, 1(1): 16-18 (1946). • 1945 March 28 ‘noise’ at Norfolk Is. not previously observed • Christened ‘Norfolk Island Effect’ • 1945 March-December two periods of intense sunspot • activity & “… these coincided with periods of intense solar • “noise”.” • Reports submitted to UK & Australia • Detections by others noted • Solar emission at 200 MHz non-thermal in origin, but “To • deduce solar temperatures of millions of degrees from this • radiation, as has been suggested … is absurd.” • “It is not in the least surprising that the Sun should emit • radio waves.” • More observations/analysis required (role of amateurs).

  12. 5. THE SEQUEL Canterbury Project I. Thomsen (Nature paper) A. Maxwell (M.Sc. Thesis) R.F. Joyce

  13. 6. CONCLUDING REMARKS Fortuitous: “Right place; right time!” Anomalies: female, family, age, education First female ‘radio astronomer’? NZ sequel Acknowledgements: Mary Harris, Bernice Jones, Bill Alexander, Gordon Burns, National Archives of New Zealand, E.R. Collins, Woody Sullivan.