The Flaming Skull Nebula. Seriously.

Bad Astronomy
The entire universe in blog form
June 28 2013 8:00 AM

The Flaming Skull Nebula. Seriously.

Planetary nebulae are among my favorite objects in the sky. When a star a bit more massive than the Sun starts to die, it blows off a super solar wind of gas. As it ages more, this wind it blows speeds up, slamming into the stuff previously ejected, carving it into weird and amazing shapes. Eventually, the entire outer layers of the star blow off, exposing the star’s hot, dense core. This floods the surrounding gas with ultraviolet light, causing it to glow.

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

Once it starts to emit light, the gas cloud becomes visible to us on Earth, and we can see the weird forms it can take. This structure can be quite fantastic, depending on how exactly the star was spinning as it blew off those winds, what angle we see this at, and the chemical composition of the gas.

Advertisement

In the case of the planetary nebula Sh2-68, though, we have an added factor: motion. The star at the heart of this nebula is moving rapidly through space, and it happens to be in a location in our galaxy where there is more gas and dust between stars than usual. So as it moves, the gas it blows off is itself blown back, like a dog’s hair is blown back when it sticks its head out of a car window.

The image above, taken by my friend Travis Rector using the KPNO 4-meter telescope, shows this in detail. The blue gas is oxygen (which is slightly false-color here; this flavor of oxygen is actually more greenish), and the red is hydrogen. The star itself is the blue one right in the center of the blue gas.

I could go into great detail about the overall shape of the gas, the cavities in it, the actually quite interesting physics of how the gas interacts with the interstellar gas … but c’mon. Seriously.

The nebula looks like a giant screaming head with its hair aflame streaking across the galaxy!

That is just way too cool. I used to read the Ghost Rider comic books when I was a kid, and when I look at Sh2-68, it’s hard to shake the image of Johnny Blaze on his motorcycle, his flaming skull grinning maniacally as he wreaks vengeance upon evildoers.

Or maybe that’s just me. Either way, this is no illusion; we are seeing the gas blowing back due to what is essentially wind, with the parallel tendrils and streamers of gas flowing downwind adding to the effect. The red color Travis used doesn’t hurt, either.

'Nuff said.

TODAY IN SLATE

Politics

Smash and Grab

Will competitive Senate contests in Kansas and South Dakota lead to more late-breaking races in future elections?

I Am 25. I Don’t Work at Facebook. My Doctors Want Me to Freeze My Eggs.

The XX Factor
Oct. 20 2014 6:17 PM I Am 25. I Don’t Work at Facebook. My Doctors Want Me to Freeze My Eggs.

Republicans Want the Government to Listen to the American Public on Ebola. That’s a Horrible Idea.

The Most Ingenious Teaching Device Ever Invented

Tom Hanks Has a Short Story in the New Yorker. It’s Not Good.

Brow Beat

Marvel’s Civil War Is a Far-Right Paranoid Fantasy

It’s also a mess. Can the movies do better?

Watching Netflix in Bed. Hanging Bananas. Is There Anything These Hooks Can’t Solve?

The Procedural Rule That Could Prevent Gay Marriage From Reaching SCOTUS Again

  News & Politics
Politics
Oct. 20 2014 8:14 PM You Should Be Optimistic About Ebola Don’t panic. Here are all the signs that the U.S. is containing the disease.
  Business
Moneybox
Oct. 20 2014 7:23 PM Chipotle’s Magical Burrito Empire Keeps Growing, Might Be Slowing
  Life
Outward
Oct. 20 2014 3:16 PM The Catholic Church Is Changing, and Celibate Gays Are Leading the Way
  Double X
The XX Factor
Oct. 20 2014 6:17 PM I Am 25. I Don't Work at Facebook. My Doctors Want Me to Freeze My Eggs.
  Slate Plus
Tv Club
Oct. 20 2014 7:15 AM The Slate Doctor Who Podcast: Episode 9 A spoiler-filled discussion of "Flatline."
  Arts
Brow Beat
Oct. 20 2014 9:13 PM The Smart, Talented, and Utterly Hilarious Leslie Jones Is SNL’s Newest Cast Member
  Technology
Future Tense
Oct. 20 2014 4:59 PM Canadian Town Cancels Outdoor Halloween Because Polar Bears
  Health & Science
Medical Examiner
Oct. 20 2014 11:46 AM Is Anybody Watching My Do-Gooding? The difference between being a hero and being an altruist.
  Sports
Sports Nut
Oct. 20 2014 5:09 PM Keepaway, on Three. Ready—Break! On his record-breaking touchdown pass, Peyton Manning couldn’t even leave the celebration to chance.