supernova!

Warning: Astronomy themed posting

One evening in August of 1975 my mate Neil Bone phoned our house unexpectedly. We were in the same class in high school, geeky boys keen on science. Neil was already becoming a star, so to speak, in the amateur astronomy world, getting mentioned regularly in the "Circulars" of what was then the Junior Astronomical Society. He wanted me to run outside and confirm that the constellation Cygnus had unexpectedly gained a new star: a "nova". I knew Cygnus well enough and an extra star was obvious to the naked eye.

Eventually we heard that somebody else had spotted it an hour or two earlier. Nova Cygni 1975 did not become "Bone's Nova" but this was a pretty exciting episode all the same.

Just as Bone's Nova fell a little bit short for Neil, so Nova Cygni 1975 fell a little bit short of the ultimate astronomical event. A remarkable, dramatically brightening star, it was nonetheless not a supernova.

A white dwarf is an extremely exotic object, the mass of the Sun condensed to an object the size of the Earth. A spoonful does indeed weigh a ton. There are a few that are fairly easy to see for yourself, with a small telescope. Come to one of my classes and - weather allowing - I'll show you one; possibly the most exotic object I can let you see in a small telescope, and one of the most innocuous looking.

A white dwarf next to a normal star, in a binary system is in a difficult place. Gas falls onto it continually from the normal star. Maybe more and more hydrogen gas piles up on the surface of the white dwarf until there is a thermonuclear explosion, a naturally occurring hydrogen bomb on a huge scale. Then the star brightens up dramatically as a nova, a "new star". The accumulated gas is blown off in a huge explosion and the star settles back down to its previous timidity. This is what Neil and I - and of course many others - saw in 1975.

Much more desperate stuff can happen, much more rarely. If enough gas falls onto the white dwarf it may collapse catastrophically and blow itself completely to bits in an enormous nuclear explosion, a Type Ia supernova. Then this single star shines briefly with the brightness of all the stars of a galaxy. It is believed that these events all have more or less the same intrinsic brightness, so they play a vital role in estimating the distances to distant galaxies and thus estimating the age and future fate of the Universe.

I've been thinking of all this recently because there has just been a Type Ia supernova in M101, one of the nearest galaxies. People with modest telescopes may be able to spot it as it brightens over the next week or so, a single, ferociously luminous star 20 million light years away, a poor wee white dwarf driven beyond the Chandrasekhar limit and thus to fiery destruction; a much more dramatic event than the nova Neil spotted in 1975, but involving the same sort of object.

A supernova in one of the nearest galaxies: Neil would have loved this.

The future

It's foolish to worry about the future. It doesn't exist.

But we can definitely think about how we'll deal with the present as it changes over the next few years. The most immediately pressing job was to get the new DACE programme out. If you're not one of the lucky people with a personal paper copy it's available, as always, on the website. All of us are really happy, first that it exists at all, but also that there are as always things in it we're excited about: novelties in teaching, unusual mixes of disciplines and so on. Maybe I'll mention one or two of my own here over the next couple of weeks. We're hoping for lots of enrolments!

In the longer term we'll be looking at a new future situated (at least administratively) in the centre of the University. We'll certainly be looking at new kinds of job. We'll have new challenges to meet (not least a financial one) but possibly new opportunities also.

In a time of change, a newly fluid situation, it's interesting to look at other organisations. Perhaps there will be new ideas for how we should look, or indeed confirmation that other universities find something like us useful. So today I was fascinated to look at the website of Cambridge University's Institute for Continuing Education. I found a unit similar to DACE with subject academics, active in their own disciplines, delivering a range of courses of various lengths, academically sound but widely accessible, lots of possibilities for mixing disciplines. This blog from their Director (a scientist, someone whose research papers I can understand) gives a nice example of this inter-disciplinarity - as well as reminding us that Cambridge has quite a heritage to draw on. Of course we have some heritage ourselves (as Dave Clark, for one, will show in his day school on Astronomy in Glasgow over the centuries).

The next few years will be interesting, that's for sure. We'll certainly be keeping core activities going but there will equally certainly be changes and it seems likely that some at least will be surprising. As we think about our own possible futures it's reassuring to know there are examples like Cambridge out there.

Tribes of Science

A dentist appointment this morning made it easiest for me to travel by car, and also meant I was coming to work after 9.30. So I happened to hear a very nice, short programme on Radio 4. It is probably not the first time that an anthropologist has looked at a group of scientists, but it's the first time I've come across such a thing away from academic literature. So the programme mixed little snippets of Diamond Light Source science with words from the staff scientists: how they worked together and interacted, both among themselves and with visitors using the facility, how they felt about their role of service (as opposed to leading and driving scientific projects), their dress code: a "tribe of science". Perhaps he viewed them from a vantage point similar to Margaret Mead in Samoa - and I wonder how far they told him what they thought he wanted to hear, or should hear. No sex though, at least on the radio.

So I very much appreciated a scientific story humanised by the voices of the scientists themselves, and the agenda of an outside view. Just the sort of thing you also get in a forum where scientists themselves will tell their stories, where you can inquisite them, change the agenda, ask them how they feel as humans about geeky and abstract pre-occupations; in university adult education in fact. Good thing the brochure will be out soon.