This is a really comfortable conference on many levels. Many of the talks are being given by young astronomers (graduate students) and the audience is a rich mix of amatuer astronomers, professional astronomers from all types of universities (from major research schools to community colleges), professional science communicators (like the great Martin Ratcliffe), and students of all ages. There are only about 50 people, and most are local and no each other. We are in a pleasant room with plesant company observing science. AND I found a squishy sofa next to a power outlit to sit on. Really, what more could I ask for?

Talks are flying fast a furious and are presently addressing the area of stellar atmospheres. The last talk was written on Carbon stars and what can we learned by looking out what they look like spatially an over time. He described how these stars seem to fluctuate over time and reminded us that lots of carbon comes from dust being churned up an spit out of elderly red stars (Asymtopic Giant Branch Stars) that are in the process of dieing. There was something about the speakers talk that reminded me of sluffing off skin cells, and that really wasn’t an image I wanted. Aren’t you glad I shared that with you? Thing is – carbon does come from what’s left behind as elderly stars as they loose their outer layers. Mira, the poster child for AGB stars, actually looks like a comet when viewed in the ultraviolet because it is leaving behind so much of itself as it flys through space. Being made of the remnants of supernovae is kind of sexy. But Carbon – the building block of life – is really the snail trail through space of a red giant that is falling apart. Okay – analogy beaten until dead.

And now we’re on to discussing how close in Giant Planets (Hot Jupiters), effect their parent stars. If the parent star is at all non-spherical (and they do tend to bulge because of rotation), the planet can exert enough torque on the bulge to effect the rotation and precession of the star!

(The talks are only 10 minutes long! Eek!)

And now Hubble! Steve Hawley, who was an astronaut, is going over HST. I didn’t remember the original HST plan was to bring the telescope back to Earth every three years and service it. On May 12, the 5th (but called 4th) servicing mission of the HST should launch. The mission launched in 1990! This means there should have been at least 1 more servicing mission than we’ve had time (at least because the first (0th) servicing mission wasn’t part of the plan, but we launched HST with vision problems). If the next mission launches okay, HST will be good to go for a number of years, with new batteries, gryos, and even a new Control Unit. (And since I have a really cool project I get to do *only* if HST’s ACS camera works again, I really really hope things launch and work. And no, I can’t tell you about the project ) ACS is the 7th priority (planned for day 3 of 5), below WFC-3, batteries, STIS and Fine Guidance System. Astronauts, fly well, fly safe, repair quickly, and please give us back our telescope in wonderfully working order.

In case STS-125 fails (HST repair mision with Atlantis), they will launch Endeavour as STS-400. I love the number (Error 400 = Bad request).

We are going to break, and I’m going to post and get cookies.

There are certain meetings / star parties I love. This is one. Texas Star Party is another (selfish plug alert: Anyone want to invite me to go next year?) I’m really looking forward to going to NEAF in a couple of weeks. Small meetings of diverse groups of astronomy lovers are simply a good thing.

I actually laughed loudly enough to scare the dog when I read the following earlier today from here:

Please! Get your facts straight, people!
Your original assumption is faulty, the Sun does not need to heat up and expand in a billion years, it will not “run out of fuel” in a billion years.

The reason the Sun is predicted to heat up and expand in a billion years, is not lack of fuel, but the interference of the ash products, iron and silicon, with the internal fusion processes. There will still be 95 percent of the current amount of Hydrogen in the sun then, as there is now. Please talk to a knowledgeable Solar Physicist.

Removing those ash products so they will not interfere with the normal operation of the Sun, is merely an engineering problem.

Any person who uses a fireplace realizes that occasionally you need to remove the ash products.

Please talk to a knowledgeable Solar physicist before you go making simplistic unthinking fearmongering statements for the sake of entertainment. Yes, it is a danger. No, it is not an inevitability. Currently we don’t know how to fix it, but in 1910, we didn’t know how to make manned Moon landings, either. We know about the problem, we can work on the engineering solutions.

Let me say, it is not my habit to laugh out loud at comments. Nor is it my habit to share my dog scaring laughter publicly. This comment was posted publicly however, and I have to admit that the idea that we over hyped the eventual expansion of the Sun for the sake of entertainment is hilarious.

No, um, we weren’t fear mongering. Sorry.

So here’s the facts of physics. The Sun is a plasma gas. As it creates heavier elements, they fall to the center. Currently, in the center of the Sun there is a region that is of sufficient density and temperature that  hydrogen is fusing into helium. The helium, weighing more than hydrogen, has no desire to leave the core. When this region of burning is completely filled with helium, burning will stop, the Sun will collapse a bit, and a shell of hydrogen will end up burning around the core (causing the Sun to expand back out).

Now, in the above comment the idea is put forward that we should be able to clear this “ash”, the helium, out of the way to keep the Sun on the main sequence burning hydrogen. Let’s just disregard the fact that you can’t exactly fly a spacecraft into the center of a star even in the Star Trek universe. Ignoring the problem of building something that will function under pressures and temperatures that turn everything into plasma, my question is, move the helium to where? This is like saying you’re going to swim to the 10ft deep bottom of a swimming pool (that is undergoing nuclear reactions), and pick up all the rocks some little kid threw in and just leave them 3 feet up from the bottom of the pool. Yes, you can pick them up and hold them there, but when you let go, they kind of fall straight back down to the bottom. Now, in general I would tend to carry the rocks up from the bottom and just set them on the side of the pool, but the Sun doesn’t exactly have an edge and it seems very silly to remove the helium all together. This helium is a non-trivial amount of mass, and the energy requirements to move it (F=ma, and W=Fd, even in the future) are HUGE. If you have this kind of energy and technology, wouldn’t it be easier to just move Earth? (Which after all weighs less then all that helium). And if you’re tired of Earth, if you have that much energy, you can probably grab a few asteroids or a small moon, hollow them out, and make them a colony vessel that can just go somewhere else altogether.

I do firmly believe their is a bright technological future of unimaginable wonder in front of us. I also believe in particle physics and know that things (like space craft) tend to melt in the centers of stars. So… I vote for taking Earth to Alpha Centauri.

Seriously though, trying to determine the formation date of a stellar object is tricky business, and the best direct method we have involves studying the ratios of different nuclear isotopes in stellar atmospheres. Called nucleo-chronometry, this process first asks “In what ratio where all the elements in this star formed?”, and then looks to see in what ratios those elements are actually observed. In a perfect universe, there will be a baseline distribution of stable elements that appear in textbook perfect ratios side by side with unstable elements with long but varied half-lifes. It is this combination of different decay rates that allow the star’s age to be determined. For instance, if a star was expected to form with some amount A of element Fo* and some amount B of element Fi* (where Fo has a half life of 1 billion years, and Fi has a half life of 3 billion years), than after 3 billion years, we’d expect to see only only 1/2^3 A= 1/8 A of element Fo and 1/2 B of element Fi. Only one element is required to get a rough estimate of how old a star is – in fact carbon dating uses just the element Carbon-14 to measure the age of old organic materials – but more reliable results come from looking at more then one element.

This technique was recently used to identify a population III star likely from about the first generation of low mass stars, that was born roughly 13.2 billion years. This star, named HE 1523-0901, is perhaps the oldest known star in our galaxy. At first glance, this is just another story of someone going, “Oh neat, an extreme,” but the reality is, determining the age of a star is a real bear, and, in many cases, it just isn’t possible. This piece of research, lead by A. Frebel of my graduate alma mata the University of Texas, and including T. Beers, my undergraduate advisor at M.S.U., required a lot of hard work, and 7.5 hours on the ESO’s Very Large Telescope in Chile.

On paper (or at least on the computer screen), this process sounds pretty straight forward, but in reality it is a messy problem. Observationally, nucleo-chronometry is challenging because it requires high quality (specifically high signal-to-noise) high resolution spectroscopy. In plain English, the light from the star has to get spread into an extremely long and bright rainbow that allows astronomers to study the specific shades of color that correspond to the electron energy levels in different isotopes of atoms. This can be done with the brightest stars without a lot of pain using couple-meter telescopes. To look at faint stars (in other words, most stars), many-meter behemoth telescopes and long exposure times are required. This is hard work, requires good observing conditions, and the data reduction is something known to make graduate students (including myself) want to throw things. The results are worth it, but it can take as long to acquire and reduce the data as it does to measure the elements in the data.

Obtaining and quantifying the data aren’t the only difficulties. Stars are created out of recycled materials, and one star may have had a dozen different types of supernovae, each with their own element distributions, in its ancestry. Star’s atmospheres can also be altered, either (in the case of extremely low mass stars) through mixing of internally enriched materials, or via mass transfer from a nearby star (where mass transfer may be just a nearby red supergiant undergoing normal mass loss that falls onto the star being observed). When looking at the atmosphere to determine age, one must have some sense of what is original, what should have been their originally, and what if anything ended up there after the fact.

This is good science that only comes from whatever one calls the typing equivalent of elbow grease.

But, this is also the type of work that Frebel and her team did. They were able to determine age estimations using 7 different atomic ratios. Having done my own painful share of isotopic measurements, my hat is totally off to these guys for this clean bit of science. They successfully dated the oldest star around – no bling required.

I could insert a joke about how this is harder than getting a date with Paris Hilton or Britney Spears, but… That would just be google fodder.

*Elements Fo and Fi are just made up