4/1/2003: v838, a cool huge star

[Undertoad]

http://www.space.com/scienceastronom...ho_030326.html

space.com says this is one of the "coolest stars ever known", which is hard to dispute - just look at it! (It's the red thing.)

At an estimated 3600F it's less than half the temperature of the sun. But at the same time, it's gotten much brighter. They are trying to figure out why it's behaving the way it is. In a matter of months, it has gotten brighter without getting hotter, and the dust cloud that surrounds it has been expanding in spectacular fashion. They say it isn't a supernova for that reason - a supernova would get way hotter. The link above has a link to an animation that gives us the detail of the expanding dust, and an explanation of light that I don't understand at all.

This must be one of the nicest-looking Hubble images yet. Simply awesome - and a space mystery, to boot.

[Elspode]

The neat thing about this image is that it is explained as being an example of a "light echo". Light emitted by the star is reflected off of different sections of the expanding dust cloud surrounding the star, causing light from those differing areas to arrive at Earth at successively later and later times. In effect, we are seeing a sort of naturally animated exploded view (no pun intended) of the star, not terribly unlike MRI's or CAT scans that show successive layers of the human body (or so I divine from reading on the image series that this shot is taken from).

Of course, you need to watch the actual animation to appreciate this, but man, this picture is awesome just by itself.

[xoxoxoBruce]

Fudge ripple with a cherry?

[goethean]

Indeed, <a href="http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=light_echo_animation_030226_02,0.gif&cap=ANIMATION:%20Four%20images%20of%20V838%20Mon.%20The%20different%20colors%20in%20the%20nebula%20reflect%20changes%20in%20the%20color%20of%20the%20star%20during%20its%20outburst.%20CREDIT:%20NASA,%20ESA%20and%20H.E.%20Bond%20(STScI)">the animation</a> is an even neater visual.

[Slight]

3 words:

Bad fucking ass.

[Drydock]

Thank you soooo much. i actually lost that marble one day when i was playing in my yard. i thought that i would never see it again. If you could tell me where it is that you saw it, there would most certainly be a reward when i finally got it back. i am also looking for this one:



If you find it, let me know please. It is one of my favorites and it is kind of one of a set.

i would be most appreciative. All of the Others are laughing at me. You know, "Lost your marbles, have You?" and all that.

Ta-taa!

[Griff]

Go ahead... touch it.... I double dog dare ya!

[Nightsong]

That is one pretty pic! I thought people had to get to a certain "high" to see shit like that...lol. Mother nature supplies us with an even better one.:p

[kisrael]

That's like the tackiest thing I've seen in space! It looks like "Star Wars Night" at a 1970s Disco!

[juju]

Perhaps the star's brightness is a function of the density of the dust cloud partially obscuring our view? The same thing happens on a cloudy day when you try to to look at our sun.

It reminds me of a cordial cherry. Mmmmmmmmmm.

[bjlhct]

Juju, they find the temp by wavelength (color) of the light, not by intensity. (brightness)

Hotter things give off shorter wavelengths of light. It's called blackbody radiation.

[juju]

But Undertoad said that the star was getting brighter without getting hotter. So the temperature is remaning the same while the brightness is changing.

I was just suggesting that the brightness might appear to be changing because dust clouds are reflecting or obscuring some of the light. But when the dust clouds move away (move? Would they be in orbit, or just stationary?), more of the star's light is able to get through, thus increasing the brightness.