Wednesday, May 24, 2006

Observing report 5.20.06

I meant to post this earlier, but it's been a hectic week. I'm going to Italy for two weeks tomorrow and should have lots to say about the birthplace of Galileo when I get back.

In the meantime, I did manage to get out stargazing on Saturday night. I didn't go all the way out to Virginia, but instead hit my local site near Damascus, MD. Usually, this is not a very dark site because it's located too near the I-270 corridor, which is quite built up with housing and shopping malls. But for some reason Saturday was uncommonly clear with virtually no haze or ambient light at all. One of those nights where, instead of hunting and hunting for objects, you just point your telescope and there they are.

Unfortunately, the steadiness was pretty bad, so planets and doubles were out of the question. But galaxies... that was a different story. I made the limiting magnitude out at 5.5 or 5.6 (based on the Astrocards chart, which I'm not sure is particularly accurate). But still, that was very good for this location.

Anyway, I hit a bunch of the Coma-Virgo group where there were sometimes as many as 4 galaxies in a single field of view -- lovely! And a few old favorites like M81, M51, and M57 (below). I was able to just get a hint of the arm between the two disks of M51 and for the first time saw the little star lying next to the Ring Nebula.

Friday, May 19, 2006

"Life on Mars"

Not the scientific concept, silly, the David Bowie song.

OK, yes, his album, "Hunky Dory" was already 15 years old when I was really into it (more than 15 years ago). But there's nothing like listening to the albums of your youth to make you feel all that teenage angst all over again. Anyway, "Life on Mars," is kinda like that for me. And the digitally remastered version sounds great, nothing like the old turntable.

Wednesday, May 17, 2006

Expand your word power

I have an extreme and inexplicable fondness for the word "perijove,"—probably because I've always been intrigued by words in which an adjectival or compound form uses a different root. For example "Mancunian" (someone from Manchester) or "Jacobian" (from the era of King James). Mostly because they're not at all intuitive—you just have to know.

Perijove refers to the closest approach of an orbiting body to the planet Jupiter ("Jove" being the greek version of the god's name, by Jove). Just as we have perigee/apogee for the Earth, perihelion/aphelion for the Sun, and periastron/apastron for other stars, you can extrapolate the formula to get similar constructions for the other celestial bodies:

Saturn: perisaturnum/perikrone
Moon: periselene/perilune
Mercury: perihermion
Tom Cruise: peripleo*

Wikipedia has a pretty comprehensive rundown.

* Actually, this was more apt than I intended because, of course, "cruise" already means to traverse or circumnavigate.

Tuesday, May 16, 2006

What they don't tell you about southern skies

Most amateur astronomers are aware of the fact that there are all kinds of constellations and objects that are visible only in the Southern Hemisphere—like the Eta Carinae nebula, the Southern Cross, and the Coal Sack. But what surprised me on a trip to New Zealand last year is that everything is upside down.

Think about it—to get to the southern hemisphere you travel down the earth's surface, past our equator and underneath the ecliptic. So all of a sudden the ecliptic is in the north, not the south, which means that the moon is never where you think it ought to be. But, more shocking, the moon is upside down! Here's the drill: if you're in New York looking at a first quarter moon crossing the meridian due south, the bright side is to the right (west) and the dark side is to the left (east). You start walking south until you get to the equator. Now the moon is directly overhead. If you keep walking south until you get to Chile, the moon starts to move toward the north. If you turn around and stare at the moon, the lit side is still facing west, but now that's to your left. What used to be the top of the terminator in New York is now the bottom.

And, naturally, all the constellations that are near the ecliptic—like Orion—are upside down, too.

When I was in New Zealand, my young cousins were telling me about the only constellation they knew, "the Pot." I had never heard of this, so I asked them to point it out to me one night. Come to find out, it's actually Orion. Only, Orion upside down with the head and shoulders pretty low in the sky. So all you see is the bottom of his tunic, upside down. Kind of like a pot.

Thursday, May 11, 2006

The speed of two wheels

I'm trying to keep this blog on topic, but right now my entire psyche is consumed with the Giro d'Italia (bicycle race). For those who don't obsessively follow European road racing, this is one of the Grand Tours (3-week races) along with the Tour de France and the Vuelta a Espana, that are the crowns of the racing season. I'm alternately blessing and cursing OLN for providing a live internet pay-per-view broadcast of each day's stages, which means that I can't get any work done until after 11am. (Luckily, I work for myself, or this would NOT be an option.)

The speed of gravity

I gather it's been more or less proven that gravity moves at the speed of light, and not instanteously (or at an infinite speed) as has been previously suggested. This is the sort of issue that makes me wish I'd stuck with Physics and Math in college, since I find both subjects really fascinating but can't even hope to comprehend 10% of them.

This is how deluded I am: I was reading a book (for the layperson, natch) about string theory, and got so excited that I bought a little volume at my local used book store about tensor calculus. Riiiight. This is the person who dropped out of calculus in first year of college because I couldn't score more than 20% on any of the tests due to a complete inability to figure out limits. Sadly, it was one of those things where I understood the explanation and could follow along in class, but as soon as I had to do a proof on my own it was like my brain turned into molasses. Very humbling. I remember thinking, "this is what stupid people feel like."

Anyway, since I never seem to learn from the past, I thought I might try and slog through this paper online: The Speed of Gravity – What the Experiments Say.

Monday, May 08, 2006

Wedding presents

Regular readers will be thrilled to know that I managed to find a pair of shoes in time for the wedding, which was a lovely event. The father of the groom, who's more than a little eccentric, gave a long, rambling speech full of limericks he invented over the years and passed around 11x17 color photos of the groom in various embarassing poses from his youth. Of course, there had to be a grand gesture at the end (I was hoping in vain for something along the lines of "My Big Fat Greek Wedding"), which turned out to be a giant, framed certificate from—you guessed it!— the International Star Registry!

Anyone who hangs out with astronomers knows that the International Star Registry (ISR) has absolutely no legal or scientific standing anywhere. It's like selling people real estate on the moon. Basically, the deal is you send the ISR money to name a star after you. They send you a beautiful, expensively printed certificate and a star chart showing where "your" star is. Which is all very lovely and sweet except that you could name a star yourself, print yourself a certificate, save the $139 and it would be just as valid as theirs. Astronomers have their own internationally agreed-on classification and naming systems and are not going to start referring to SAO 067174 in the constellation Lyra as "Huggie Bear" just because you paid the ISR to call it that.

This issue came up on our astronomy club listserv and most of the people who piped up expressed disgust at the way the ISR preys on people's ignorance and sentimentality. But of course, someone had a story about their husband who was dying of cancer and the kids got together and named him a star from the ISR. Like my friend's father, they really meant well and wanted to make a special gesture.

The ISR website is careful to state (in small, hard-to-read type at the bottom of the page) that "International Star Registry star naming is not recognized by the scientific community." But on their "About Us" page (a large link at the top of the page), they say, "Because these star names are copyrighted with their telescopic coordinates in the book, 'Your Place in the Cosmos,' future generations may identify the star name in the directory and, using a telescope, locate the actual star in the sky." So, on balance, they're making it seem more legitimate than it is. And as far as I can tell, they don't claim anywhere that they won't sell the same star to different people—not that that really matters since it's all meaningless anyway, and furthermore there are a dozen other companies doing the same thing.

As with any flim-flammery, some people will say that if it makes you feel good or happy or loved, then what's the harm? Apart from fleecing the credulous, I'm not sure that there's any direct harm caused by the ISR. But there are plenty of wrong ideas that are harmful, so I don't think we ought to be encouraging even the ones that seem innocuous.

If you know someone who's considering buying into one of these star-naming scams, send them to the website of the International Astronomical Union (the people who ACTUALLY name stars) where they ruthlessly and humorously debunk the entire industry, while simultaneously making you feel like a total asshole for even considering it. Genius!

Friday, May 05, 2006

Mother's day, shmother's day

Actually, tomorrow is Astronomy Day, but—as previously mentioned—I'll be at a wedding instead of hanging out with my astronomy club wishing the skies would clear up. So far, the forecast is . . . how shall I say . . . rainy. Which is also going to make for a fun wedding, especially since I'm getting all tarted up in a sleeveless frock meant for the middle of summer and some sort of impractical shoes that I hope to purchase at the last moment later today. (If you're female and you hate to shop, getting dressed up can be a monumental pain in the @$$.)

But back to the topic at hand. Having completely neglected to create an Astronomy Day design to sell on Stargazer Tees (a major marketing faux pas), I decided I couldn't let Father's Day get by me. And yes, Mother's Day is only a week away, but how many mothers do you know who have enough time and energy to stay up half the night stargazing? So we'll be giving Mother's Day a complete miss and going straight to Father's Day:

Any feedback from the peanut gallery? I'm guessing that women will be buying this shirt, not men, so it has to simultaneously appeal to women and just possibly look like something a guy would wear. Which is pretty tough to parse out and something I'm still learning. Personally, this is too sentimental for my taste, but I've come to discover that my taste is not mainstream enough to build a t-shirt retailing venture on.

Tuesday, May 02, 2006

Where it all started

Actually, I can't remember where it all started—I was always interested in the sky and the stars. Even though stars were scarce in New York City, we went camping often enough so that I learned the major constellations. In high school I even took some classes as the Haydn Planetarium. In those days the classes were held in the basement and you had to walk through the dusty meteorite exhibit to get to them. Nothing like the the snazzy, multimedia Haydn Planetarium of today.

I have this defining intellectual memory, however, of reading a book I found on the shelf at home: Nigel Calder's Einstein's Universe. He has a chapter called "Directed Futures" in which he uses the concept of the "light bubble" to explain space-time. Imagine a spaceship with beacons on the outside. A flash of light will spread outwards from the spaceship at the speed of light, and since nothing can travel faster than that, that light bubble defines the spaceship's possible future:

Now, put our spaceship near a massive object. Gravity displaces the light-bubble off-centre and as a result the astronaut's future is somewhat biassed in a certain direction in space—towards the massive object. An interchange occurs between time and space. Its meaning assails our prejudices about time more fiercely than the slowing down of clocks. A black hole again clarifies the point. Imagine the spaceship just crossing the dire perimeter at the surface of a large black hole. The astronaut is trapped for ever. His future now lies inside the black hole, because the light constituting the light-bubble cannot, by definition, escape from the black hole.

That image has stayed with me ever since, which is probably a testament to Calder's engaging style, at least as much as the subject matter.

Monday, May 01, 2006

Observing report 4.29.06

Despite perfectly clear skies all day, as I was driving out to the wilds of Virginia a bank of high, thin cloud rolled in from the west. This was the view from the observing site at sunset:

Plenty of folks turned up so we made the best of it. It was supposed to be our second chance at the Messier Marathon but I didn't even make an attempt because of the conditions. Many of the early objects were going to be lost in the sunset and the cloud bank wasn't going to help. (I later found out that one of our club members actually stuck it out and logged 84 Messiers!)

Also, I was operating on a major sleep deficit and knew I wasn't going to have much stamina. The problem with driving for an hour to your observing site is that you have to drive back when you're tired, on the Capital Beltway, with a whole bunch of drunk drivers on a Saturday night. Not to mention the deer. So, it's a bad idea to wait until you're really tired. My preferred method of staying awake is to drink coffee before I leave for home and crank up my iTunes sing along playlist. Although I've noticed that when I'm really sleepy, I forget to sing along.

So, basically, I took it easy and checked out Saturn, a few galaxies in Leo, and made another attempt at Comet Schwassman-Wachmann. The latter was sadly almost lost in the eastern light dome and high cloud (I feel a bit cursed trying to view this object). But I did get one sketch of the C fragment:

If I'd been able to stay up later when it was higher in the sky, I think I would have had a better time of it. Couldn't find the B fragment at all -- I didn't have any current charts with me. I took a quick peek at Jupiter before I packed up at about 10:30. I'm pretty sure there was a little moon shadow just starting to cross the disk, but the view was boiling in the low altititude, so I couldn't be sure.