Sun Puffs - sense of scale (APOD 29 Oct 2006)

d_weye · Post by **d_weye** » Sun Oct 29, 2006 12:57 pm

A lovely Sun image. I have found that I enjoy pictures of the sun more when I can get a sense of scale. How large is this sun eruption? How would an earth diameter compare with the size of this eruption? Earth's mass compared with the mass ejection? Does anyone know the scale that this image is representing?
Daniel

Andy Wade · Post by **Andy Wade** » Sun Oct 29, 2006 3:21 pm

d_weye wrote:A lovely Sun image. I have found that I enjoy pictures of the sun more when I can get a sense of scale. How large is this sun eruption? How would an earth diameter compare with the size of this eruption? Earth's mass compared with the mass ejection? Does anyone know the scale that this image is representing?
Daniel

Well, this is not precisely accurate, but...
Start from the centre of the sun image, go out in the direction of 2.30 (on a clock face), about one third of the radius of the sun out from the center is a white dot. That's not far from the approximate size of the earth in relation to this sun image. Small aren't we?

Edit: The diameter of the sun is approximately equal to 109 Earth diameters.
So that white dot is actually a bit bigger than the earth.
And we're even smaller than I first thought.

d_weye · Post by **d_weye** » Mon Oct 30, 2006 12:09 am

Oh, I can now see that it is a picture of the entire sun diameter. I had thought that that outer edge was the edge of the disturbance not the edge of the sun. So in fifteen minutes the shock wave traveled, what, twenty or thirty earth diameters or about two earth diameters per minute or three to for hundred miles per second. Definutly super-sonic. Any figures on the quantities of max ejection in earth masses?
Daniel

DavidLeodis · Post by **DavidLeodis** » Mon Oct 30, 2006 12:33 pm

Thanks Andy. Like d_weye I had also thought the image showed a close-up of an active area, not the Sun's disc. It's not at all obvious that it shows the disc.

The APOD mentions the WIND spacecraft. I've looked at several search result pages but I cannot find out what WIND stands for (if it is an acronym). If it is not an acronym then why is it capitalised, as that makes it look like one? I would be grateful if anyone can clear it up for me. Thanks.

Andy Wade · Post by **Andy Wade** » Mon Oct 30, 2006 6:05 pm

DavidLeeds wrote:Thanks Andy. Like d_weye I had also thought the image showed a close-up of an active area, not the Sun's disc. It's not at all obvious that it shows the disc.

Ah, Well I just assumed it was the 'whole' Sun in the picture, I could be wrong of course, you know what they say about assuming things...

DavidLeeds wrote: The APOD mentions the WIND spacecraft. I've looked at several search result pages but I cannot find out what WIND stands for (if it is an acronym). If it is not an acronym then why is it capitalised, as that makes it look like one? I would be grateful if anyone can clear it up for me. Thanks.

It measures effects in the Solar Wind, so I expect it really does mean 'wind'.
There's probably a joke in this somewhere but I won't state the obvious...

It is strange that they have capitalised the whole word though. I expect it's just to distinguish it as being different from 'wind'.
They use both on their webpage. A bit confusing.

Here's the Wiki page link:
http://en.wikipedia.org/wiki/WIND

DavidLeodis · Post by **DavidLeodis** » Mon Oct 30, 2006 6:33 pm

Thanks Andy. It is confusing capitalising the word WIND.

When I did the search for WIND spacecraft I got lots of hits and I tried a number of them, but I did not spot the Wikipedia one (it was probably on a later page). I find the Wikipedia website to be very good for information on astronomy related things that are not explained, or not well, in other links. Cheers.

Andy Wade · Post by **Andy Wade** » Mon Oct 30, 2006 9:17 pm

DavidLeeds wrote:Thanks Andy. It is confusing capitalising the word WIND.

When I did the search for WIND spacecraft I got lots of hits and I tried a number of them, but I did not spot the Wikipedia one (it was probably on a later page). I find the Wikipedia website to be very good for information on astronomy related things that are not explained, or not well, in other links. Cheers.

Yeah, Wiki is pretty good IMO. However, not all of the people making changes/additions are experts in their field, in fact probably most of the people doing it are just 'interested' people. So some of the info may not be accurate. It's one of the problems with Wikipedia. I have some contributions on there myself, but they get added to/chopped by others of course.
I try to keep things referenced properly to well regarded published sources.
It's not perfect, but it is a good antidote to all the spam emails, and porn/rubbish sites out there on the web.
Wikipedia and the APOD and LPOD sites are my current favourite places to visit online.

Starship Asterisk*

Sun Puffs - sense of scale (APOD 29 Oct 2006)

Sun Puffs - sense of scale (APOD 29 Oct 2006)

Re: Sun Puffs Oct 29 2006 sense of scale

Oh yeah

WIND spacecraft

Wikipedia