evolving,” says Moore, who is now web editor at the
Astronomical Society of New South Wales.
Keen to see the potential data locked in the glass
plates, in 2006 Vaughan used a custom-built suitcase
lined with rubber pillows to transport 650 plates to
Cambridge University, where the Automatic Plate
Measuring Machine at the National Astronomy
Facility was capable of scanning each image in
layers, thus ensuring every star was included.
When the images came back from Cambridge,
Vaughan and Moore assessed the quality of each
plate and, using software, extrapolated the stars’
positions and modern co-ordinates to determine
how much they had moved in the time since the
photograph was taken.
“To get a historic baseline and see things change
in time is very difficult in astronomy,” Moore says.
“We can’t wait around and see a star go supernova.
We have to get all of the information from what we
can see today and however far back our records go. So
any kind of historic record, even sketches that date
back before photography, are useful in understanding
how celestial objects and systems evolve.”
The entire AC collection is now housed at the
Powerhouse Museum. When Moore was cataloguing
the fragile glass plates, she found that the years
hadn’t been kind to them. Some were broken; the
silver coating on some had oxidised to a solid black;
mould had started to take hold on others.
On one glass plate, Moore could make out,
among the smattering of dots, the curve of something
that didn’t resemble any celestial body. Its identity
remained a mystery until the plate was scanned at
Cambridge. It was a partial fingerprint – a mark
among the stars to remind us of those who captured
and catalogued the sky.Former medical researcherIVY SHIHis ascience
writer and communicator based in Sydney.The goal is to take 800 separate images of each region
of the night sky over 10 years.
Given this, it seems easy to view the AC and
Carteas historical remnants of humanity’s ambition
and attempt to have some degree of mastery over the
heavens. But the glass plates and catalogue have a
legacy that’s still playing a part in modern astronomy.
Each glass plate’s smattering of black spots is the
light of stars past – a unique window to the state of the
night sky up to a century ago. The plates are effectively
time capsules that allow astronomers to study
the evolution of galaxies. Space is a constant
roil of activity and motion of celestial bodies,
dying, colliding and being born. Within the
plate images are data that opens up new
possibilities in astronomical research.
This is because of the speed at which light
travels. It takes 1.25 seconds for moonlight to
reach Earth. The Sun’s light takes more than
eight minutes. Whenever we peer through a
telescope at Proxima Centauri, Earth’s closest
star other than the Sun, we’re looking at starlight
that began its journey to Earth 4½ years ago.
As Alan Vaughan’s research student 20 years
ago, Lesa Moore
painstakingly created
a digital catalogue
of the glass plates at
Macquarie University.
She spent months
going through the
plates, transcribing
what they contained.
“The idea [was] to
get... the variability
and the movement
in the stars so we can
understand how little
sections of space areFiled in numbered bespoke
boxes, the glass plates and
their attendant logbooks
are held at the Powerhouse
Museum, Sydney. Only 650
plates have been digitised.
1911 The first Perth
Astrographic Catalogue
is published.1892 The first glass plate is
measured at Melbourne
Observatory.
1900 Perth Observatory joins
the effort, taking over the
zones originally assigned to
Rio de Janiero Observatory.
1913
MODEL T FORD
1902
WOMEN ACHIEVE
FEDERAL SUFFRAGE
COLLECTION: MUSEUM OF APPLIED ARTS AND SCIENCES. PHOTOGRAPHER CHRIS BROTHERS38 – COSMOS Issue 86
ASTROGRAPHIC CATALOGUE