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Lunch Hour Lecture: On supernovae and serendipity

By ycrnf01, on 13 October 2014

Like a white dwarf, autumn 2014’s first Lunch Hour Lecture was dense, full of energy and tightly packed (but in this case, time and not space, I might add).

Psyched for my first Lunch Hour Lecture, I was ready to explore the world of supernovae with a 45-minute guided journey through the stars, namely, ones in the process of exploding very dramatically.

Radiating enthusiasm and demonstrating expertise from start to finish, Dr Steve Fossey (UCL Physics and Astronomy) took a capacity audience on a whistle stop tour of January’s discovery of a Type ia supernova, memorably named SN 2014J, and situated in our neighbourhood galaxy, the sci-fi sounding, Messier 82.

After summarising the rules for supernovae discovery (there are two options: looking, and not looking but accidentally finding), Dr Fossey gave a short overview of history’s accidental supernova discoveries.

One scenario for Type Ia supernovae: a white dwarf accreting matter from a neighbour till it becomes unstable Credit: European Southern Observatory

One scenario for Type Ia supernovae: a white dwarf accreting matter from a neighbour until it becomes unstable
Credit: European Southern Observatory via Oli Usher

Beginning with Tycho Brahe’s find in 1572 – labelled SN 1572 – which rewrote the rules of astronomy, he moved on to Johannes Kepler’s discovery of SN 1604 in, wait for it, 1604 (are you seeing a pattern here?) and finally, and more recently, SN 1987A, found by astronomers in Chile.

What we have now with SN 2014J is clearly a rare and incredibly useful opportunity to study an ‘up-close’ supernova in the telescopic age.

I won’t do Dr Fossey a disservice by explaining the technical points too deeply but his clarity and ability to explain clearly were enjoyable for an interested novice such as myself.

Supernovas are made of the same stuff as me and you, Dr Fossey explained. Describing the chemical components involved in the explosive process, he also outlined the fascinating tools and measurements that astronomers have devised to understand and compare supernovas.

There followed a tale of unlikely discovery and the significance of all that followed.

UCL’s teaching observatory, the University of London Observatory in Mill Hill, plays host to students studying a variety of physics and astronomy degrees and provided the setting on a fateful cloudy afternoon in January.

Dr Fossey and a group of four undergraduates (sat in the front row of the Lunch Hour Lecture) stumbled across the exploding star when, instead of the scheduled practical, he “gave the students an introductory demonstration of how to use the CCD camera on one of the observatory’s automated 0.35–metre telescopes.”

After checking multiple databases that it hadn’t already been recorded, and was indeed a suspected Type ia supernova, his students took an all-important #supernovaselfie before Dr Fossey spent a stressful evening filling out an official, if not rather complicated, form.

A painful three hours ensued until, at 3am that morning, the find was acknowledged with an email from the International Astronomical Union – thus beginning the process of confirmation and cross-referencing.

So why was it missed? Well, it wasn’t entirely. Days earlier, there were multiple sightings by a few amateur astronomers but these were not recorded and came to light after the official documenting.

Acknowledging these, Dr Fossey expressed how fortunate only they had been that the circumstances conspired in such a way that the lucky accident had happened.

Statistics can sometimes sound meaningless but Dr Fossey was quick to contextualise the significance of the find in terms of distance. In the grand scheme of things, the discovery of SN 2014J is just down the road (where Earth is the house in this scenario) making it the closest Type ia supernova discovered in the past 42 years. Depending on whether you’re a glass half full or glass half empty kind of person, it was (dis)heartening to hear how utterly vast the universe is.

So, what’s the importance of supernovae? Apart from being made of the same stuff existing in everything, ever (including the very blood running inside of you, me, Dr Fossey as well as everyone who has ever existed), they help us to know more about the strange and amazing goings-on in the universe in which we live.

And who isn’t a little bit curious about that?

You can watch past events on YouTube and check out other Lunch Hour Lectures happening this term in the Events Calendar.

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