Starship Asterisk*

geckzilla wrote:

sallyseaver wrote:What I really like about this image is how it shows how a nebula is raw material for forming stars. And you can see where star formation has used up the surrounding nebula gases.

My understanding is that the orange-red gas around the orange crescent shape (that Alexander331 is referring to) is mostly hydrogen gas with some helium gas that is created by the multiple stars that are being born in the region. The hydrogen-helium gas is bumping into a clump of existing nebula gas and pushing it into the crescent shape. The proto-stars themselves are too small to be seen with the resolution of the image.

As a star forms, it actually creates and kicks out hydrogen and helium nuclei and electrons--the beginning of its stellar wind. You can see the mostly hydrogen (red) with some helium (orange) gas as part of star formation in the images below; these are images of proto-stars (called proplyds) from a study that the Hubble Space telescope did of the Orion Nebula. (The black in these images are multi-element gases that absorb the full visible spectrum of light.)

Click to view full size image

Those pictures illustrate artifacts around point sources. WISE resolution really isn't that great, and the stars tend to be all fuzzy partly because of the wavelengths, and I think partly also because of the way the data gets combined... Anyway, some sharpening filters have been applied which create some dark spots and rings, and infrared PSF's tend to form rings of dots.

It is also difficult to analyze the colors in this picture because they are more artistic than anything, but even when they are presented scientifically in the typical WISE color palette, red can sometimes be hydrogen-alpha emission, and other times it can be warm dust. Oftentimes it's both together. Context is important. And I think that saying this color is hydrogen and that color is helium is totally wrong. The bands being presented are wide, and you can see more about them here: http://www.astro.ucla.edu/~wright/WISE/passbands.html

Looking at the graph it's easy to see that all of them will cover multiple emission lines, even if you don't know exactly where the emission lines are. Note also that we are supplied no information about exactly which bands were even used, though I suspect it is mostly a combination of W3 and W4.

"Only the NASA/ESA Hubble Space Telescope, with its high resolution and sensitivity, can take such detailed pictures of circumstellar discs at optical wavelengths."

sallyseaver wrote:What I really like about this image is how it shows how a nebula is raw material for forming stars. And you can see where star formation has used up the surrounding nebula gases.

My understanding is that the orange-red gas around the orange crescent shape (that Alexander331 is referring to) is mostly hydrogen gas with some helium gas that is created by the multiple stars that are being born in the region. The hydrogen-helium gas is bumping into a clump of existing nebula gas and pushing it into the crescent shape. The proto-stars themselves are too small to be seen with the resolution of the image.

As a star forms, it actually creates and kicks out hydrogen and helium nuclei and electrons--the beginning of its stellar wind. You can see the mostly hydrogen (red) with some helium (orange) gas as part of star formation in the images below; these are images of proto-stars (called proplyds) from a study that the Hubble Space telescope did of the Orion Nebula. (The black in these images are multi-element gases that absorb the full visible spectrum of light.)

Click to view full size image

rstevenson wrote:

Alexander331 wrote:Right to the brightest star on the top right edge of the picture, after clicking on the image, there is an orange structure. What is it ?

Pretty much everything we see in this picture that isn't a star (or a distant galaxy) is the result of energy streaming out from stars pushing against the gas and dust around them. Most of it looks quite chaotic because there's a lot of stars doing the pushing, but the area you mention looks like a smallish concentration of gas and dust with just a few particularly large and bright stars doing the pushing, so you get a nice little bubble shape. That, in a nutshell, is what the stars are doing: blowing bubbles.

Rob

APOD Robot wrote: NGC 7822: Stars and Dust Pillars in Infrared

Explanation: Young stars themselves are clearing out their nursery in NGC 7822. ... This field spans around 40 light-years at the estimated distance of NGC 7822.

Ciao Bella Francesco,

Chiedo il permesso di usare la tua immagine [APOD 2017, 19 novembre] di NGC 7822 sul mio sito web. Il mio sito web avrà un blog e il suo scopo è quello di supportare l'introduzione della mia nuova teoria per la formazione stellare e la formazione dei pianeti.

Sito: http://massvortex.science

Cordiali saluti,
Sally Seaver

rstevenson wrote:

Alexander331 wrote:Right to the brightest star on the top right edge of the picture, after clicking on the image, there is an orange structure. What is it ?

Pretty much everything we see in this picture that isn't a star (or a distant galaxy) is the result of energy streaming out from stars pushing against the gas and dust around them. Most of it looks quite chaotic because there's a lot of stars doing the pushing, but the area you mention looks like a smallish concentration of gas and dust with just a few particularly large and bright stars doing the pushing, so you get a nice little bubble shape. That, in a nutshell, is what the stars are doing: blowing bubbles.

Rob

Alexander331 wrote:Right to the brightest star on the top right edge of the picture, after clicking on the image, there is an orange structure. What is it ?

heehaw wrote:Yes! Yesterday's APOD was serenity while todays is, as Boomer says, psychedelic!