Comments on: Shocking!

By: Anne

Anne — Wed, 29 Aug 2007 16:01:39 +0000

Pulsar wind nebulae also often have bow shocks, often very hot because pulsars get such large kicks (tens of kilometers per second?) at birth. They also often have tails, but apparently the “tails” are not exactly what they look like: the gas is moving at the wrong speed to have simply been left behind. We’re not sure quite what they are, but there’s some evidence that it’s some sort of jet thrown off by the pulsar. Is it possible to look at the velocities of the gas in Mira’s “tail” and see whether it’s actually been left behind or whether it’s been actively ejected in that direction?

By: ad

ad — Tue, 28 Aug 2007 23:24:01 +0000

I’m also curious to hear what people are saying about Abell 520.

http://physicsworld.com/cws/article/news/30849

By: IseFire

IseFire — Fri, 24 Aug 2007 19:47:22 +0000

Great post and beautiful images!

By: Alan Tennant

Alan Tennant — Thu, 23 Aug 2007 19:06:25 +0000

The first picture is very nice, I just wish it was more detailed, gets a little fuzzy a little to quickly as you zoom in.

The bright bit at the (lower left)most corner has some odd circular patterns in it that you see when you download the full resolution tiff and zoom in.

http://img205.imageshack.us/img205/5386/185516mainamirafullpy4.png

I seem to have made them less obvious by drawing the blob around them but you can still see them, like someone at NASA used the picture as a mat to put there hot coffee on.

alan2here@gmail.com

By: Jon H

Jon H — Sun, 19 Aug 2007 22:51:47 +0000

I expect there are many aging, famous stars who go around trailing gas, but you just never hear about it.

By: eric gisse

eric gisse — Sat, 18 Aug 2007 20:58:56 +0000

Oh dear, the replies are extra cranky today.

By: Michael T

Michael T — Sat, 18 Aug 2007 20:48:07 +0000

A little something on Abell 520.

http://www.centauri-dreams.org/?p=1407

By: Brian

Brian — Sat, 18 Aug 2007 16:33:20 +0000

Beautiful, Julianne. Gorgeous and fascinating. Thanx. I must confess, though, I came here today hoping to hear something about Abell 520.

By: Mike Schuler

Mike Schuler — Sat, 18 Aug 2007 09:41:01 +0000

A bow shock created by an object hurtling through the near vacuum of space is easily explainable by perpetually expanding matter and space.

By: Quasar9

Quasar9 — Sat, 18 Aug 2007 08:19:17 +0000

Hi Julianne, interesting post on bowshocks and the Mira image
I like the contrast with the lower image in Orion’s sword, instead of the star ramming into some more slow moving interstellar gas, some fast moving gas is (probably) ramming into the star

Now people can say they have seen a real shooting star, albeit in the ultraviolet and – not quite with the naked eye
Compared to other red giants, Mira is travelling unusually fast, possibly due to gravitational boosts from other passing stars over time. It now plows along at 130 kilometers per second, or 291,000 miles per hour. Racing along with Mira is a small, distant companion thought to be a white dwarf. The pair, also known as Mira A (the red giant) and Mira B, orbit slowly around each other as they travel together in the constellation Cetus 350 light-years from Earth.

By: Mira « Meng Bomin

Mira « Meng Bomin — Sat, 18 Aug 2007 02:55:28 +0000

[...] There is another good post on the topic by Julianne of Cosmic [...]

By: Ellipsis

Ellipsis — Sat, 18 Aug 2007 00:29:37 +0000

Just as a fussy detail: the blue light in a reactor
core are shocks produced on Earth that do light up — although that
case (Cherekov light) is a little different.

Sonoluminescence is another case. There are more, in plasma physics etc.
But none of these will supplant astronomical shocks anytime soon

There are many nice
Youtube videos of sonic shockwaves from aircraft.

By: Michael T

Michael T — Fri, 17 Aug 2007 22:42:53 +0000

Curious as to what you think about the recent observations of Abell 520. Appears to throw a new wrinkle into the present conjectures regarding the nature of dark energy/matter.

By: My underwear is on backwards » Reason #4236 why I have a physics degree

My underwear is on backwards » Reason #4236 why I have a physics degree — Fri, 17 Aug 2007 22:21:03 +0000

[...] above image is Mira plowing through the interstellar medium. Julianne over at Cosmic Variance gives an [...]

By: Mid August Friday « blueollie

Mid August Friday « blueollie — Fri, 17 Aug 2007 21:37:07 +0000

[...] Cosmic Variance has a nice post (with photos) about deadly astronomical beauty (e. g., layers of dying stars being blown off of the star, [...]