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Background History

I first became interested in Astronomy at the age of 10 when my teacher got the class to 'find out about' the planets. I never looked back.

Less than a year later on 25 April 1969 I had the remarkable fortune to witness the Bovedy meteorite travelling low over the northwest horizon from my home in Cheam, Surrey, UK (later IAU code 499), noting green and red 'sparks' coming from the brilliant head followed by a long bright trail. Within the hour, the story of the brilliant meteor I had been telling my parents about was confirmed when it was mentioned on the late evening TV news. Several stony fragments were recovered from Bovedy and Sprucefield in Northern Ireland, the largest piece (from Bovedy) weighing nearly 5kg.

I went on to University College London to read Astronomy in 1976. There I used the facilities at the Mill Hill Observatory (observatory code 998) including their X-Y coordinate plate measuring machine.

This led me to try making astrometric measurements of asteroids and comets from images taken with a 300mm focal length f/4.5 camera mounted on the end of the Dec axis of a 6" reflector. I was assigned observatory code 499 (Cheam), but because of the small aperture and very short focal length none of the results were particularly useful.

Around the same time I was the Deep Sky sub-editor of The Astronomer magazine (TA) and through the boundless energy of the main editor Guy Hurst we were able to offer a measuring service to many of the observers in the UK that had good telescope equipment but lacked access to precision mechanical measuring machines.

Not quite as timely as CCD astrometry is today, observers would expose images on film, develop the negatives and post them to me, often by the next morning. I would then arrange time at the Mill Hill Observatory and measure the negatives and reduce the measurements. A single negative could take 30 minutes to 1 hour to measure and then often a longer time reducing the X-Y co-ordinates to RA and Dec having manually identified stars and extracted their positions and proper motions from the four volume SAO Catalogue.

A list of some of the Observatories that I helped with measuring between 1977 and 1985 appears below:   

Observer(s) Observatory Observatory code
F Van Looy Rayleigh 002
H Clough, R H McNaught MacNairston Observatory 487
A Young Hemingford Abbots 489
A Young Burwash 576
B Manning Stakenbridge  494
N.W. Scott Altrincham  495
J-C Merlin Le Creusot 504
R L Waterfield Woolston  993
Some notable achievements back then were
  • Our first astrometric position of a comet (Comet Chernykh 1977l, reported in IAUC 3104) from negatives by Brian Manning
  • Positions for NEO 1978 CA from negatives by Brian Manning, reported in IAUC 3200. (Just imaging a fast moving NEO was a big achievement. Brian's positions were the first reported for 1978 CA other than those from the discovery site the European Southern Observatory, La Silla 809)
  • Other NEOs measured 1977 - 1982 included 
    • (2368) Beltrovata = 1977 RA
    • (3102) Krok = 1981 QA
    • (4197) 1982 TA
    • (3757) 1982 XB

    A list of IAU circulars from this period containing references to work by Peter Birtwhistle are listed here.


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