Podcaster: Richard Drumm
Title: Space Scoop: Space Graffiti
Organization: 365 Days Of Astronomy
Link : astrosphere.org ; http://unawe.org/kids/unawe1610/
Description: Space scoop, news for children
Bio: Richard Drumm is President of the Charlottesville Astronomical Society and President of 3D – Drumm Digital Design, a video production company with clients such as Kodak, Xerox and GlaxoSmithKline Pharmaceuticals. He was an observer with the UVa Parallax Program at McCormick Observatory in 1981 & 1982. He has found that his greatest passion in life is public outreach astronomy and he pursues it at every opportunity.
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Transcript:
This is 365 Days of Astronomy. Today we bring you a new episode in our Space Scoop series. This show is produced in collaboration with Universe Awareness, a program that strives to inspire every child with our wonderful cosmos.
Today’s story is: Space Graffiti
The Universe is filled with many galaxies that have perfectly uniform shapes. But the uneven S-shape of the galaxy in this 2006 picture in today’s album artwork is messy, like a graffiti artist has hurriedly drawn it by hand!
How did this spiral galaxy end up with this weird shape? Astronomers think that a long time ago, another galaxy tugged at its spiral arms unevenly, making one arm longer than the other.
Sounds like something from a Sponge Bob cartoon…
The longer arm looks like a hook that is used to hang meat, so astronomers have given it a funny nickname: the Meathook Galaxy.
Ewww… That’s not Sponge Bob…
It’s 50 million light years away and is seen in the southern skies in the constellation Volans, the flying fish. This is one of the 12 constellations that were added in the late 1500s by Dutch navigators as they sailed southward around Africa. The original take on the current name was Piscis Volans, literally fish flying.
The great astronomer John Herschel proposed shortening the name to one word and the new constellation name stuck. Volans it was!
The galaxy is also called NGC 2442 & NGC 2443. It gets 2 NGC designations, one for each arm, which is not all that unusual. Let’s just call it 2442.
There is also a nearby cloud of gas called HIPASS J0731-69, which is a cloud of gas only with no stars, but this is a bit more unusual. It was discovered by the neutral hydrogen detecting, H-One Parkes All Sky Survey with the Parkes 64 meter radio telescope. If you’ve seen the movie “The Dish” you’re familiar with Parkes.
It’s likely that this gas was pulled away from 2442 in the same close pass that distorted the galaxy. Another example of a starless cloud of gas like this is the so-called “Leading Arm” of the Magellanic Stream.
This is a stream of high velocity gas that appears to have been stolen from the Milky Way by the Small Magellanic Cloud and it’s larger partner in crime, the Large Magellanic Cloud.
The close-up inset image in today’s album artwork is from the Hubble Space Telescope and focuses on 2442’s nucleus and the more compact of its two spiral arms.
ESO’s observations also highlight the other end of the life cycle of stars. Dotted across much of the galaxy, and particularly in the longer of the two spiral arms, are patches of pink and red.
This color comes from hydrogen gas in star-forming regions: as the powerful radiation of new-born stars excites the gas in the clouds they formed from, it glows a bright shade of red called hydrogen alpha.
The interaction with another galaxy that gave the Meathook Galaxy its unusual asymmetric shape is also likely to have been the trigger of this recent episode of star formation. The same tidal forces that deformed the galaxy disrupted clouds of gas and triggered their gravitational collapse to form new stars.
Hey, Here’s A Cool Fact:
In 1999, a massive star at the end of its life exploded in the shorter arm in a supernova.
By comparing older ground-based observations, previous Hubble images made in 2001, and these shots taken in late 2006, astronomers have been able to study in detail what happened to the star in its dying moments.
By the time of this 2006 image the supernova itself had long since faded and was not visible.
Thank you for listening to 365 Days of Astronomy!
End of podcast:
365 Days of Astronomy
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The 365 Days of Astronomy Podcast is produced by Astrosphere New Media. Audio post-production by Richard Drumm. Bandwidth donated by libsyn.com and wizzard media. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. This year we will celebrate more discoveries and stories from the universe. Join us and share your story. Until tomorrow! Goodbye!