Just a quick note: Atlantis is back home. Interestingly, that press release doesn’t mention the debris that was seen that delayed the landing. Anyway, with another one under their belt, we’re one step closer to a Hubble servicing mission.

Check this out:

What is it? It’s the Shuttle Atlantis (on the left) as it was leaving the International Space Station on September 17. It was taken from the ground by astrophotographer extraordinaire Thierry Legault. Most people don’t know that, under the right conditions, you can use a telescope to actually see the Shuttle and ISS this clearly — and even then it ain’t easy.

But what makes this so fracking cool is that this isn’t any old picture: the two space-borne objects were crossing in front of the Sun at the time:

Holy Haleakale! Amazing. Even better, the transit lasted less than a second, so Thierry had to be right on the money to get that picture. The ‘scope he used, a 150 mm Takahashi, is one I drooled over at a star party some years ago… but at $8600 it’s a tad out of my range.

Go to Thierry’s website to see a whole slew (slew! Haha!) of other incredible shots. The man is an artist.

… and the podcasters’ names might be familiar to you.

The podcast is called Astronomy Cast, and the hosts are Fraser Cain (from Universe Today and, of course the Bad Astronomy & Universe Today forum) and Pamela Gay, formerly of Slacker Astronomy.

Yes, I said "formerly". Slacker has gone in a different direction, and so Pamela hooked up with Fraser to make Astronomy Cast. The first episode about Pluto went online on September 10, and the second, about searching for extrasolar planets went live on September 19.

You can get the show through iTunes, too. In fact, that’s probably the best way, since that makes it easier fro Fraser and Pamela to measure metrics (how many people are downloading the show, etc.).

You can discuss the episodes in a new section of Bad Astronomy & Universe Today bulletin board. Full disclosure on this: I’m one of two admins on that board; I mean, c’mon: duh, but I feel I should make sure this is as obvious as it an be.

Anyway, give ‘em a listen. You’ll find Fraser and Pamela are making a good team. And I might drop in every now and again sometime in the future…

Spitzer Space Telescope images of the two T dwarfs: HD 3651 B on the left, and HN Peg B on the right. Those pictures may look a lot alike, but they are indeed of two different stars; compare the background stars.

Astronomers using the Spitzer Space Telescope have found a couple of brown dwarfs orbiting nearby stars. While brown dwarfs around other stars are seen fairly often, these ones are nifty for several reasons.

One of them, HN Peg B, is interesting because it’s fairly low mass, about 20 times Jupiter’s mass. This makes it what’s called a T dwarf. Those of you who’ve taken Astronomy 101 may remember that stars are classified according to their spectra, which corresponds roughly to their mass and temperature. The hottest, most massive stars are O stars, then, going lower mass and cooler, they are B, A, F, G, K, M. M stars are the lowest mass stars that can fuse hydrogen into helium into their cores. But brown dwarfs are cooler and lower mass. They get added to the end of the list above, as L and T dwarfs. T dwarfs are so cool that they can actually have methane in their atmospheres (in hotter stars, methane breaks down).

HN Peg B orbits a star about 60 light years away, relatively close by as these things go. Since it’s close, getting an image of it is easier (it appears brighter, and farther away from its parent star). The parent star is itself interesting, in that it’s a solar analogue, a star like the Sun. For those keeping track at home, it’s a G0, or slightly more massive and hotter than the Sun. No T dwarf has ever been seen orbiting a star like this. It’s probably common (G stars make up about 10% of all stars, and some are bound to have brown dwarf companions), but T dwarfs are so faint compared to their parent stars that they are really hard to detect. This one can be seen in images because T dwarfs put out most of their light in the infrared, where G stars are relatively dim. That increases the contrast and makes the T dwarf easier to see.

But the very neatest thing about the T dwarf is that it’s young: HN Peg A, as it’s called, is probably only about 300 million years old (this can be found by looking at a number of characteristics, including how fast it spins (younger stars tend to spin faster), how much lithium it has (lithium is destroyed easily in stars, so more lithium means the star is younger), magnetic activity (tied to spin, so young stars have stronger magnetic fields), and other properties).

Assuming that HN Peg B formed together with A, which is likely, that means the brown dwarf is young, too. All other T dwarfs ever seen are much older, like a billion years or more, so seeing one that’s this young is cool. Astronomers can learn more about T dwarfs!

Learning more is always good. Always.

The other T dwarf was found orbiting the star HD 3651 A, which is about 35 light years away. This one is cool because a planet has already been detected orbiting HD 3651 A. It’s a Saturn-mass planet orbiting the star about as far out as Mercury orbits our Sun. The orbit of the planet is known to be highly elliptical, which is unusual for such a close-orbiting planet — tides from the star tend to make the planets’ orbits circular. It’s been thought for a while that a massive object farther out might keep the inner planet orbit elliptical, and this is now confirmed. The T dwarf HD 3651 B orbits the star about 10 times farther out than Pluto orbits the Sun, which is a fair walk, but close enough that it can warp the inner planet’s orbit.

I studied brown dwarfs for a few years, and I’m pretty interested in them. I suppose I’d call myself an educated layman when it comes to these guys (as opposed to real experts like the ones who ran these studies), so I’m not fully up on what’s what. But it’s nice to see the field making so much progress, and as usual I’m pretty eager to find out what will happen next!

Salon magazine’s website has a lot of articles I disagree with (like trying to link autism with vaccines) and a lot I agree with. They just posted an article indicating the Bush White House may have been controlling media access to climate scientists. This article makes an interesting case, but it’s not as solid as what happened earlier this year (oh, just search for "Deutsch" in my blog search engine), so I’m not sure what to think about it.

Evidently, WH emails indicate that they were controlling what media could access which scientists, the implication being that the WH was trying to spin global warming. We know for a fact they’ve done that in other cases, so more evidence isn’t surprising. My question is how strong this evidence is. My Senator, Barbara Boxer, is looking into this. I might send her an email about it as well.

Update: British scientists have written a letter to ExxonMobile asking the company to stop funding groups that lie about the science of global warming. Very cool.

Carnivals?

Physics.

Skeptics.

Now we can prove we doubt things!

Update: I added a picture below of the three folks involved with this blog entry; in my rush to post this last night from the Las Vegas airport I forgot to add it initially!

In a recent blog entry, I said that a lot of deals in astronomy (and science in general) are done at bars. Something about the atmosphere, the collegiality, the sense of comrades; they lubricate the gears of progress.

I wasn’t kidding. I just literally sat through it.

If you’re an amateur astronomer, you know the name Tim Puckett: his images of the sky are legendary. He’s an artist when it comes to taking pictures of astronomical images. He runs a fleet of telescopes from his base in Georgia. He has ‘scopes all over the country, and people to operate them.

The other night, Tim got a phone call from one of his operators. In a routine imagining run, they found a bright star in an image of a galaxy, and when they checked old images it wasn’t there. They checked to see if it might be an asteroid, a chunk of rock a mile or two across that happened to get in the way. The check turned up nothing.

The operator was getting excited. Was it a supernova, the titanic death spasm of a massive star? They needed to confirm it using a different telescope, preferably one as far from the original as possible to minimize any errors. Unfortunately there were no other well-placed ‘scopes in Tim’s network, so the operator called him.

And where was Tim? Sitting in a bar with a dozen other astronomers! At the time, there was a meeting of astronomers and educators going on. It was after hours, and the scientists had gathered at a bar to blow off steam. This turned out very well for Tim indeed…

Gina Brissenden was sitting next to him — she’s part of "Out of the Rain Productions" – and overheard. She told Tim that her friend Jake Noell-Storr – who was also there at the bar — might be able to help. Jake had the phone number for the operations room of the MDM telescope, a 2.4 meter behemoth in Arizona. Jake made the call, and handed the phone back to Gina.

Gina introduced herself as an astronomer from Steward observatory, and asked if the folks at MDM could give Tim a hand. The answer? Of course!

This is the wonderfulness of astronomy: those professional astronomers stopped what they were doing so they could help some amateur astronomers they don’t even know to confirm a supernova. They got the coordinates from Tim and put the ‘scope on the field immediately. Within minutes he got the word back from MDM that there was definitely a bright star in the field. A few minutes later another call came in: they checked old records, and the star wasn’t there. It was looking good—not 100% confirmed, but it was pretty much a lock. Tim had bagged a supernova!

Remember: this was discovered by what is technically an "amateur" astronomer, and confirmed within minutes — just because they asked! — by a major professional observatory.

Spirits ran high after that. Literally, in fact, as Gina went to the bartender, told him the news, and asked him to create a new drink called a Supernova.

If you’re wondering how I know all this, the answer should be fairly obvious by now: I was sitting right there the whole time. I didn’t participate, but instead soaked it all up (for the record, the Supernova drinks didn’t come out until after 1:00 a.m., and I had a 7:30 meeting so I bagged on the drinks). The next day, the supernova was indeed confirmed for real, and was at a magnitude of 17.4 when discovered– about 20,000 times fainter than you can see with your unaided eye.

Imagine! This galaxy, this nearly anonymous galaxy a few hundred million light years away might be thought to have no direct impact on us on Earth. But a mighty star in that distant galaxy ran out of fuel, exploded, and flooded the Universe with light. Across that crushing distance the expanding sphere of photons expanded, diluting as it spread out. By the time the that sphere touched us here, even big telescopes were only able to catch and count a few thousand photons.

That’s not enough light to illuminate a gnat, but it was enough to have a profound effect on us.