The famous Crab Nebula supernova remnant.

The AAS Conference has concluded, but there’s still a lot of exciting science going on. Here are the big stories from the final day and a half.

Sadly, I missed the first talk on Wednesday because I had to get my own presentation ready. It was by Manfred Schüssler of the Max Planck Institute on the Solar magnetic field.

I did, however, see David Koo of UC Santa Cruz give his talk on the CANDELS Survey*. CANDELS is a massive Hubble Space Telescope survey to image as many distant galaxies as possible in areas of the sky that have already been extensively studied in other wavelengths such as the infrared Spitzer Space Telescope and the Chandra X-ray Observatory. It will be one of the biggest studies ever on the evolution of galaxies and rare types of galaxies, covering 250,000 in total.

Later, Doug Leonard of San Diego State spoke on supernovae—specifically, supernovae of red supergiants, which are actually about a third of all supernovae (another third or so come from blue supergiants and the rest are Type Ia explosions of white dwarfs). We don’t actually know how supernovae explode because the rest of the star above the exploding core should be too heavy for the explosion to get out. In this entertaining talk, Dr. Leonard explained the evidence that supernovae do not explode symmetrically and how this could actually make them work.

This morning, Dolores Knipp of the University of Colorado Boulder described the current state of space weather. The upshot is that space weather can still cause big disruptions on Earth, but the good news is (and I was very heartened to hear this) that we are finally hardening our infrastructure against a catastrophic solar storm. Hopefully, we won’t have to worry about that by the time the next solar cycle comes around in the mid-2020s.

I gave a short presentation on my research this morning along with some other interesting planet-related talks. Here is a link to my slides.

And finally, Hernán Quintana of the Pontifical Catholic University in Chile related his thirty-year struggle to build a strong home-grown astronomy education program in Chile, a country that had not been able to do so for many years despite hosting some of the best observatories in the world.

Other highlights:

• Gravitational deflection of light as predicted by Einstein has been used to measure the mass of a white dwarf for the first time.**
• The Milky Way lies in an unusually empty part of the universe, making it hard to measure the expansion of the universe accurately.
• Observations of Comet 67P/Churyumov-Gerasimenko suggest that 20% of Earth’s xenon came from comets, and probably a lot of organic material, too.

*CANDELS is the correct spelling. Dr. Koo deliberately changed the spelling to make it easier to Google.

**Gravitational lensing, which makes a background star appear brighter, has been used for many years, but this is the first use of an observed change in a background star’s position to measure a star’s mass.