Starship Asterisk*

Chris Peterson wrote:

Anthony Barreiro wrote:Why are sunspots bright in CaK while the surrounding regions are dark in CaK?

blueberrysun_friedman_960_i.jpg

They aren't. The image has been inverted. This is what the Sun actually looks like in singly ionized calcium- the sunspots are cooler and darker, and the surrounds are hotter and brighter, pretty much as we'd expect.

Anthony Barreiro wrote:Why are sunspots bright in CaK while the surrounding regions are dark in CaK?

APOD Robot wrote: ... This solar depiction is actually scientifically illuminating as a level of the Sun's chromosphere appears quite prominent, showing a crackly textured surface, cool sunspots appearing distinctly bright, and surrounding hot active regions appearing distinctly dark. ...

MargaritaMc wrote:Following up links and generally reading around the subject of today's Apod, I read this:

http://en.wikipedia.org/wiki/Chromosphere

Whilst the photosphere has an absorption line spectrum, the chromosphere's spectrum is dominated by emission lines.

Can anyone explain to me how the spectrum of one is taken separately from the other? To me this seems impossible - but, clearly, it is not!

MargaritaMc wrote:
Following up links and generally reading around the subject of today's Apod, I read this:

http://en.wikipedia.org/wiki/Chromosphere

Whilst the photosphere has an absorption line spectrum, the chromosphere's spectrum is dominated by emission lines.

Can anyone explain to me how the spectrum of one is taken separately from the other? To me this seems impossible - but, clearly, it is not!

http://en.wikipedia.org/wiki/Calcium#H_and_K_lines wrote:

[b][color=#0000FF][size=125]If one is observing the sun with a narrow pass spectral filter of a strong CaK and CaH chromospheric emission line one cannot see down to the [u]DARK[/u] ~ 393.37/396.85 nm photosphere.[/size][/color][/b]

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H and K singly ionized calcium lines

<<Visible spectra of many stars, including the Sun, exhibit strong absorption lines of singly ionized calcium. Prominent among these are the H-line at 3968.5 Å and the K line at 3933.7 Å of singly ionized calcium, or Ca II. For the Sun and stars with low temperatures, the prominence of the H and K lines can be an indication of strong magnetic activity in the chromosphere. Measurement of periodic variations of these active regions can also be used to deduce the rotation periods of these stars.>>

Whilst the photosphere has an absorption line spectrum, the chromosphere's spectrum is dominated by emission lines.

deathfleer wrote:

emc wrote:

deathfleer wrote:Can somebody answer me. Do these energetic particles push the Earth to correct orbit, equalizing the gravitational pull of the sun that drags it to fall into the blazing ball of fire?

Not only does the Sun make life possible here on Earth, it keeps the Earth from flying off into space. The Earth does not fall into the Sun due to the balance between the gravitational tug of the Sun and the Earth’s speed traveling through space (around the Sun). The Sun does “push” photons, flares, etc. our way and solar particles can affect certain aspects of Earth’s physics but they are not of sufficient mass to move the Earth.

thanks. It must be like a spinning top that is gradually slowing down, I thought it was like those floating things above a bonfire .

emc wrote:

FLPhotoCatcher wrote:
What are the sunspot-sized blue areas surrounded by, sometimes faint, dark (hot) 'cracks'?

I don’t know... and not intending to be disrespectful but your question reminded me of a joke…

What is the white stuff in bird poop?

More bird poop.

emc wrote:

deathfleer wrote:Can somebody answer me. Do these energetic particles push the Earth to correct orbit, equalizing the gravitational pull of the sun that drags it to fall into the blazing ball of fire?

Not only does the Sun make life possible here on Earth, it keeps the Earth from flying off into space. The Earth does not fall into the Sun due to the balance between the gravitational tug of the Sun and the Earth’s speed traveling through space (around the Sun). The Sun does “push” photons, flares, etc. our way and solar particles can affect certain aspects of Earth’s physics but they are not of sufficient mass to move the Earth.

FLPhotoCatcher wrote:What are the sunspot-sized blue areas surrounded by, sometimes faint, dark (hot) 'cracks'?

deathfleer wrote:Can somebody answer me. Do these energetic particles push the Earth to correct orbit, equalizing the gravitational pull of the sun that drags it to fall into the blazing ball of fire?

deathfleer wrote:
Can somebody answer me. Do these energetic particles push the Earth to correct orbit, equalizing the gravitational pull of the sun that drags it to fall into the blazing ball of fire?

• Not yet.