College News

11 June 2004

Plane meets planet: Royal Holloway staff and students observe Venus crossing the sun

On 8 June 2004, staff and students from Royal Holloway's Physics Department were up at 5 a.m. making preparations for the Venus transit, at the on-campus observatory. This was a once in a lifetime chance to see the planet, which last crossed the sun in 1882 and provided the means at that time for astronomers to
measure the distance from the sun to the earth. Although there will be another Venus transit in 2012, it will not be viewable from Britain.

Luckily it was a hot, clear day - the hottest day of the year so far in fact - providing beautiful, clear views of the planet. The crossing began at approximately 6.20 a.m. At 7.45 a.m. a plane from nearby Heathrow came into view - giving amazing photos, taken from the Royal Holloway Observatory via the computer-controlled astronomical telescope.

Students are currently analysing their data so that they can simulate the calculations astronomers once made from the Venus transits in the 1760s. Aya Shibahara, 21, Daniel Burgess, 26, Roxanne Christer, 19 and Grace Thomson, 21 (see photo, right) made timing and position measurements with two telescope/CCD systems, which will enable them to calculate the distance from the sun to the earth - the Astronomical Unit (A.U.)
In modern times the A.U. has been measured to very high precision by bouncing radar pulses off from Venus,and it could be said that analysis of Tuesday's transit doesn't provide anything new from a scientific point of view. However, historically, the transit was a once in a lifetime experience for those lucky enough to see it. The next transit visible from the UK will not occur until the 23rd century.
	Staff at Royal Holloway Dr Glen Cowan and Dr Pedro Teixeira-Dias (left) organised the viewing, making sure everything was in place when Venus met the edge of the sun at 6.20a.m.
Constructed in 1986, Royal Holloway's Observatory dome originally housed an 1872 Grubb Refractor telescope. This was updated to a modern 10-inch Meade LX200 telescope in 2000; a standard high-end amateur telescope. A smaller Meade 4504 telescope was placed on the roof of the Physics building, and both were used for the Venus observation. Using a home-made CCD camera adapted from a webcam, these incredible shots were taken:

From left: Venus at ingress, mid-transit and egress

For hi-res images and further information please contact Royal Holloway, University of London, Press Office:
Christine Long Press & PR Officer
01784 443967, christine.long@rhul.ac.uk

Vicky Cousins
Assistant Press & Communications Officer
01784 414480, victoria.cousins@rhul.ac.uk

Editor's Notes

The Physics Department at Royal Holloway has some interesting astronomical links. Professor Samuel Tolansky (Head of the College's Physics Department from 1947 to 1973) and Professor Moreton Moore (then a newly-hired lecturer, and still a member of staff within the Physics Department) were two of the scientists to study the moon dust brought back from the Apollo missions. The Physics building at Royal Holloway takes its name from Professor Tolansky, as does a 13 km diameter crater not far from the Apollo 14 landing site, which was named in his honour.

The telescopes used to observe the Venus transit have the following specifications:
The Meade LX200 has a mirror diameter of 250 mm and a focal length of 2500 mm. A focal reducer lens was used to observe the transit, which reduced the focal length to 1575 mm. A smaller telescope, the Meade 4504 with a mirror diameter of 114 mm and a focal length of 910 mm was also used on the roof outside. Both telescopes are equatorially mounted in order to track the stars and the sun as the earth rotates.

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