May 1st 1910 Halley’s Comet
In
1910 everyone was waiting for the return of the most famous of all
comets, Halley’s. Among the many observatories that observed
Halley’s comet was the Transvaal Government Observatory in South
Africa from April 11th until June 3rd 1910.
This
particular photograph was taken on May 1st 1910 using the
10 inch Cooke lens that had originally been made for John Franklin
Adams. On this photograph which had an exposure time of 30 minutes,
showed the tail of the comet being 15 degrees long.
John
Franklin Adams ordered a special telescopic camera from Thomas Cooke
and Sons of York in 1898 in order to complete a photographic survey
of the night sky. The battery of cameras was mounted on an English
Mount and comprised of 1 x10 inch camera and 2 x 6 in cameras. It
would be between 1903-1909 he used these cameras to photograph the
northern hemisphere stars from Godalming in Surrey and the southern
hemisphere stars from South Africa.
John Franklin Adama Telescopis Camera |
Due
to ill health John Franklin Adams was not able to undertake any
further astronomical photography so in 1909 he presented the 10 inch
camera to the Transvaal Observatory which began using the Cooke
camera in April 1910 just before the arrival of Halley’s comet.
The
photographic plates were so good that there was nothing better until
the Palomar survey of the 1950s. Even today the Franklin Adams plates
are used as references by astronomers.
Halley’s
comet was not discovered by Edmund Halley he observed it in 1682 and
noted that it followed similar paths across the sky as did the comets
of 1531 and 1607. He predicted it would return in 1759 which he did
and it was so named in his honour for his prediction.
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