Monday, June 20, 2011

Supernovae Conference Day 1

its interesting to attend a conference so specialized in a area that is not my exact area of expertise. i'm learning a lot, but i'm also tuning out a lot of details that dont fit into any "big picture" scenario that makes sense to me, even if its very relevant to the field of study of supernovae.

one interesting thing about studying transient phenomena is that you never know when they will appear and they fade over time. sometimes you apply for time at telescopes not knowing whether you will actually find anything to look at! in order to catch stars exploding, many groups of people survey over and over specific galaxies that are likely to have a supernova explosion. amateur astronomers have made a huge contribution over the years looking at the same galaxies many times and identifying changes that they see by eye!

stuart ryder focused on several candidate galaxies twice a year for 2.5 years with the gemini telescope and its adaptive optics and found 6 dusty stellar explosions!

one thing i appreciate more now is that there are A LOT of different types of supernova. Weidong Li showed that the overall split is such that about 75% of them originate from the core collapse of single massive stars and ~25% are from explosions caused by extra material falling onto white dwarf stars (see brief review: here). he also suggested that smaller galaxies tend to have higher supernova rates, but i wasnt entirely convinced of that result.

one interesting result was looking at the progenitors of supernova. its impossible to predict exactly when a star might explode, especially considering there are thousands of millions of stars in each galaxy, stars are not usually individually resolved, and most are too faint to ever detect before they go supernova. but, stephen smartt showed 5 instances where looking back at hubble space telescope images of nearby galaxies where supernovae have exploded has allowed the identification of a star before the explosion, and the lack of anything in the star's previous position after the supernovae fade.

in the images below, the white circles identify the star before (a), during the supernova (b), and after (c) the explosion. the images arent exactly the super pretty hubble images you might be used to, but they show that these stars really do explode!!

neat stuff. hope to post more tomorrow...

intro to the conference: here
summary of day 1: here
summary of day 2: here
summary of day 3: here


skywatcher88 said...

This is very interesting Stuff isn`t it? The very stardust factories where all of our molecules in each of us originated from!
Peace and Clear Skies!

heroineworshipper said...

Most of Hubble's productivity must come from the very limit of its resolution, just the minimum number of pixels to say something happened.

Paul said...

There are too few supernovae for "all of our molecules" to come from them, Skywatcher88. Much more material is produced by Asymptotic Giant Branch stars.

Rik Gern said...

This post addressed a question I had after reading the previous post; can they tell in advance if a star is going to go Supernova? The "before-during-after" graphic was an eye-opener. Is THAT what the raw data looks like? What-no pretty Hubble-esque pictures?!?