Hidden in the Light

A spectrum showing lithium in a metal-poor star

Not all the great stuff astronomers get the from sky is in the form of pretty pictures. Granted, gorgeous astrophotos are addictive, but they don’t tell the whole story of the universe. Astronomers also study data in the form of spectra. The figure above is a good example of a spectrum. Basically it tells astronomers that a star called G271-162 has a certain amount of an element called “lithium” — which is relatively rare in the cosmos compared to other elements. This star is what is known as a “metal-poor” star — one that formed in the earliest times of the universe. “Metal-rich” stars are those formed from interstellar gas and dust that has probably been “recycled” through at least one star and enriched with metals. So, if we study older stars like G271-162 and figure out how much they have of certain elements, that will tell us a lot about what elements were most plentiful in the early, early universe. Astronomers want to understand how much lithium was produced in the birth of the universe — the Big Bang — some 12 to 14 billion years ago. The amount of lithium older star will help them understand it.

You can’t take a picture of lithium, but you can study the light coming from a star — and break it up into a spectrum. If lithium is present in the star, it will show as a “dip” in the spectral line — which is exactly what you see in this graph.

Musings

Well, here I am again.

It was pointed out to me that Blogging is “In”. Sure, I saw the link to Time Magazine here. And, now PC Magazine has made it official with their article on Blogging in the new issue. Life on the cutting edge, eh?

So, I’m working on this script about Hubble Space Telescope science and I keep wondering how much people really know about this magnificent telescope and the things it is revealing to all of us. In January I was attending the American Astronomical Society meeting in Washington, D.C. and had a chance to visit a new exhibit at the National Air and Space Museum. The exhibition, titled Explore the Universe, features the Kodak-built back-up mirror for the HST. I found it really impressive. For the first time I could measure my height against a mirror the one that is capturing the photons from so many interesting things in the cosmos! I mean, I always knew I could comfortably stand inside the telescope tube, but seeing a mirror built to fit in that tube finally made the connection. If you’re in Washington, D.C., you should check it out — admission is free!

Of course there ARE bigger ground-based mirrors. I remember visiting the 100-inch on Palomar Mountain a few years back. And many of the installations on Kitt Peak in Arizona. And the twin eyes of the Keck telescopes at Mauna Kea, Hawaii. They look incredibly huge and somehow delicate during a daytime visit, but at night, these (along with the orbiting telescopes like HST, Chandra, etc.) that we use to focus on “stuff” of the universe, are the heavy lifters of Big Astronomy.

Well, it’s time to get back to the script. Anything you wanna know about? Write me at: CC dot petersen at hot mail dot com

First-ever Blog Entry!

Hi. My name is Carolyn Collins Petersen. Those of you have read through my Web site, called The Henrietta Leavitt Flat Screen Space Theater have already figured out that my interests lie in astronomy, space science, space travel, and science fiction. I’m a science writer, specializing in those subjects through books, articles, planetarium shows, a video or two, and whatever else gets me paid to write about them.

Currently I’m working on a new book for Cambridge University Press (no I can’t talk about it yet), and a script for a program about Hubble Space Telescope. And some other things that float to the top of my desk when necessary.

I thought I’d form this WeBLog to air my thoughts out on any subjects (not just the ones listed above, necessarily), and sometimes answer questions that I get from people through the Web site.

So, why start a Blog? Lots of people who have them apparently have that question of themselves, too. I was inspired by Wil Wheaton’s Blog called Wil Wheaton Dot Net. What impresses me about Wil is his willingness to open his thoughts to the rest of us, knowing full well that as a member of the acting community (and due to his work in “Star Trek: The Next Generation” and “Stand By Me”) he’s already in the public eye — and apparently dealing with it pretty well.

Anyway, I enjoy reading Wil’s thoughts, his ramblings from Inside the Entertainment Machine (emphasis my own).

So, here I am, adding to the bandwidth — sort of using this public way of working through creative blocks (when I hit them) and clearing my mind of all but the essentials that I need to keep focused on the writing project at hand.

Some correspondents have asked me how I write planetarium shows. To be sure, it’s not like writing a book, although I certainly start out with the same source material. For example, I once was asked to write a show about the Moon for 3rd graders. It had to fulfill a certain set of educational standards for kids that age, but beyond that, the approach was up to me. So, I decided to look at the Moon from the viewpoint of a cat — figuring it would give me an easy way to explain some elementary facts about Earth’s nearest neighbor. It was fun to do — and the story of a little cat guy learning about something that humans figure most cats could care less about — well let’s just say that the story was an excellent framework to hang all the info on, and 12 years later, the show is still selling like hotcakes from Loch Ness Productions (at www.lochness.com).

That one was whimsical. Others have been straight documentary, or docu-drama.

Books, on the other hand, are a slog. Hubble Vision, written in 1995 and revised in 1998, just about needed a road map to keep all the data and images straight. As I work on my new book I’m databasing all the images, press releases, chats with scientists, etc. in ACCESS so that I can keep things a bit more orderly. Now I know why writers (the ones who can afford it) have assistants!

Articles — well, articles remind me of the old Mark Twain saying (paraphrased): “Please excuse the long letter, I didn’t have time to write you a short one.”