Just back from a weekend long group of lectures about some of the latest advancements in astronomy. The lectures are run by the Department for Continuing Education at Oxford University every year, it is now in it’s 32nd year. More information can be found on their website here. They run various courses throughout the year, across many different subjects.
The loose theme of these lectures was “Exoplanets” but cover a ride range of themes too. The course starts on Friday evening with a meal and the first lecture – usually an introduction covering some of the basic themes that you’ll meet over the weekend. Saturday is the busiest with a further four lectures, and includes Two, three course meals with Tea/Coffee breaks in the morning and afternoon, there’s also some time in the afternoon to yourself or go along on an organised tour. Sunday includes another two lectures and lunch. You can opt out of the meals if you wish, or opt into accommodation also, which includes breakfast.
Each lecture is given from a person working at the cutting edge of their respective subjects, from places around the country or abroad. All where very well presented and explained. Here’s the list of lectures and their speakers in the order they were presented:
- Advances in astronomy – an introduction by DR ROBERT LAMBOURNE (Open University)
- Neutrino Astronomy by DR MATTHEW MALEK (Imperial College, London)
- Investigating the Moon by BARRY KELLETT (Rutherford Appleton Laboratory)
- White dwarfs and planetary remnants by DR JAY FARIHI (University of Leicester)
- Advances in exoplanet studies by DR ANDREW NORTON (Open University)
- Astrochemistry by PROF NIGEL MASON (Open University)
- Extremely large telescopes by DR FRASER CLARKE (University of Oxford)
Advances in Astronomy Introduction
The first lecture on the Friday evening was by Robert Lambourne who does most of the organisation for the course, it is an introduction to some of the concepts that you need to know for the further lectures, together with a run down of what to expect in the next few days.
The Neutrino Astronomy lecture was title “Seeing the Cosmos in a ν Light” (Yes that’s the greek letter “Nu”…!). It covered much of the theories behind neutrinos and some of the incredible detectors that have been built. Neutrinos are fundamental particles that pass through all other forms of matter with near no detectable interaction, this obviously makes them very hard to detect, to be in with a chance you need to make a large target area and wait patiently.
One particular detector the lecture concentrated on was the Super-Kamiokande in Japan, one he had worked on the himself, even doing some of the engineering work inside the detector. The detector consists of a 40 metre sphere full of 50,000 tonnes of pure water, buried one kilometre underground and surrounded by around 13000 bulb like light detectors. Billions of neutrons pass through the water constantly without any detection but very infrequently, one will collide with the liquid and produce a flash of light. Once detected the direction the neutrino came from can also be worked out.
The sources of Neutrinos was then discussed. Those coming from the Sun and those generated in type Ib, Ic and II Supernovas were concentrated on. And then a final look at what the neutrinos can tell us about the Universe.
Investigating the Moon
Here the title was “What is the Moon Made Of?“, a question that still needs to be answered. This talk concentrated on using X-ray’s to detect the composition of the Moon and the space missions that used the x-ray detectors the lecturer and his team had built.
X-ray detection on the Moon works by detecting x-rays emitted by the material on its surface. There x-rays are triggered by x-rays coming from the Sun, these effect the atoms in the surface which produces a change in their internal energies which then triggers the release of an x-ray, that x-ray is unique to the material that emitted it. By collecting this information you can make a detailed map of the composition of the Moon.
Their detector has currently flown on two missions to the Moon, Europe’s SMART-1 and India’s Chandrayaan-1. The first mission was used to demonstrate many new technologies including the x-ray detector itself. It also used a new type of propulsion known as an ion engine, which uses very low amounts of fuel, consequently it produces a small amount of thrust which meant it took 15 months for SMART-1 to reach the Moon (which resulted, the lecture was proud to reveal, in a Guinness world record for the slowest journey to the Moon!). The slow approach, which included around a 1000 orbits of the Earth, causes a few malfunctions in the demonstration x-ray detector, but it still managed to show it was capable before SMART-1 was directed to crash into the Moon. The second mission some years later had a more advanced detector and arrived at the Moon much quicker but a malfunction in the spacecraft meant the mission had to stop much earlier than planned.
The team are still waiting for another chance to try again.
White dwarfs and planetary remnants
This one had the grand and imaginative title “Archaeology of Extrasolar Terrestrial Planetary Systems“. It was about the end point of most of the stars (including our Sun) in the Universe – the White Dwarf. A star reaches the end of its life when it has burned through all the Hydrogen and Helium it can, at this point there is no outwardly directed pressure produced and the star goes into it’s final collapse it’s radius falls to a fraction of it’s previous size, for instance the Sun will eventually collapse into a radius similar to that of the Earth, the mass stays the same but the density increases considerably.
The majority of this talk concentrated around the possibility of planet remnants (hence “archaeology”) still remaining around the white dwarf, planets that would have been made around the same time as the star just like our own Solar System. Given the white dwarfs increased density, the gravity it creates is also greatly increased and objects moving close to the body experience large differences from one of their edges to the other and it gets ripped apart. If this happens a lot then a great disk of material is created that circles around the white dwarf. Some of this material falls on to the star and it is this we can detect.
One of the interesting things this can reveal is that it can tell us the frequency of planets around the majority of the stars in the galaxy and therefore how likely it is that planets are created around stars.
The remaining talks will be reviewed in a later blog.