Bill Ward


That’s a good catch, However from my own experience working with low res spectra is always a bit tricky.

One of the things that interests me is developing what I called “comparative spectroscopy” in the Astonomy Now article, and this turns out to be an excellent example. Although relatively low res there are definite features in this example but  strangely it’s not whats there it’s whats NOT there!

Firstly it is relatively slow moving, then there is a clear “gap” in the spectrum in the blue green part and finally there are no, usually very prominent, atmospheric lines in the near IR.

Take a look at this. https://www.youtube.com/watch?v=1pfwYQ_dM1E

(I wouldn’t trust the graph, the actual lines are OK but the instrument correction was highly experimental…)

Slow moving, with a gap in the blue/green and no near IR lines. So now we can start to see these may be related, they are definitely made of the same stuff and behave in the same way, ablation wise. With only one example and no clear shower association then it looked like a sporadic but with more examples then maybe it/they are not. THEN your into looking for parent bodies and new showers and that’s when it gets really interesting!

It’s a potentially a powerful tool but unlike nice neat orbital elements spectroscopic reduction is a lot more subtle!