Starship Asterisk*

June 5, 2012 Venus transit
iPhone image through small H-alpha telescope (Lunt)
Public outing including BBQ and kid's air Moon-walk
[No processing]
Image by Matt Cooper

I lost a number of comments I made, somehow, because I failed to login. The picture that Philip Hart posted in the discussion thread, where he had applied no increase in contrast, saturation and vibrance, makes the color of Spica to appear very "normal-blue-sky"-like to me. Fortunately, Ph...

However, when you discuss the color of the sky, I see a great problem here - the exact color of the blue sky isn't fixed. It changes. Due to the presence or absence of moisture in the sky, it changes. Due to the height of the Sun above the horizon, it changes. Due to the height above the horizon of...

The following illustrates that, perhaps, around 75,000K (Planck distribution) temperature will produce the color ratios that come reasonable close to a blue sky spectrum I found. [The blue sky spectrum, I suspect, is of an AM1 (coastal) spectrum. I have seen blue sky SEDs that have higher blue end ...

I disagree. Astrophotographer David Malin once said that A0-type star Vega, at about 10,000K, is about the same blue color as the Earth's sky. Does he live on the coast? :) This is bound to be in error, unless the sky he sees is desaturated blue. The following illustrates that, perhaps, around 75,0...

what a buzz to get my image on APOD! :-) for helio.. yes this image was captured reasonably high in the sky above the tree.. not much reddening as the stars drifted down in this field of view. was lucky to get a calm night though otherwise the tree would have been blurred out. there's a little bit ...

There are a few things a bit odd about the impressive color trails: 1) The color near the horizon does not seem to change. Atmospheric effects, even with a pristine morning, will cause some reddening or desaturation. "Never a white sun has set" - I think I just made that up, but it's true....

Well... the problem is that there is no single way of mapping color temperature to the limited gamut available with an RGB filter system. So different camera manufacturers use different algorithms. A specific temperature setting on a Nikon will look different from the same setting on a Canon. And t...

I've chased down a few more sunset pictures that I find revealing... Don't overlook the fact that the gamut of cameras is different from that of the eye, and in images with "unusual" color combinations, such as sunset images, cameras generally produce colors somewhat different from what t...

At the horizon there appears to be some clouds, nevertheless. Hugging the horizon is a thin orange-to-red layer. It is easy to imagine that here light has had to pass through so much atmosphere that even some of the red wavelengths are being scattered, though only horizontally (where light has to p...

Well, now I have another question which is an honest question, because I don't know the answer. It is why earthly sunsets are never green. You have some nice answers and I'd like to add a little to them. [Your sunset images are outstanding, btw!] The very tenuous layer of ozone does a great job of ...

take a sunset for example, where sun light is scattered the most - the sun is getting not only yellow but even red. maybe when a sun is directly above us, it is white, then adding some blue back to it would indeed make it blue in outer space? btw, I think I have seen some webpage that claimed to co...

on subject of this thread: isn't it kinda obvious that, if our sky scatters away blue light, the color of the sun = yellow we see + blue = emmm, white? That is an important viewpoint. The white solar image I gave above comes from sunlight that has been somewhat scattered by our atmospere. A correct...

Helio George wrote: Thanks much, Ann! You're very kind considering all the "corn" I dished out in the blog. :) Hah!!! I wondered if George Cooper was you! Helio George (Sun George?) linking to a blog by George Cooper, who takes a great interest in the Sun - that was a bit of a coincidence...

I disagree. The Sun definitely has a warm cast when viewed directly through a neutral density filter, and it definitely has a yellowish cast when projected, as long as the projection is viewed in an area shielded from skylight. I see this from my observatory at 3000m elevation with very clean, dry ...

So indeed, as the intensity of the Sun changes, so does its apparent hue. This is readily obvious if you simply view the Sun through different neutral density filters. Most anybody who views the Sun directly (briefly!) will critically report that it appears white. Surprisingly, many see yellow or y...

This also demonstrates the inadequacy of color names in actually describing colors. Our eyes easily perceive a significant difference in color between 555nm and 558nm. Some may, but 3 nm will likely make little to no difference. Are there some experiments that demonstrate your view? If you have a m...

Thanks much, Ann! You're very kind considering all the "corn" I dished out in the blog. :) As for the wavelength where the solar emission peaks as seen from below the atmosphere, Chris said it was at 555nm. This may be a peak wavelength for a Sun when the sunlight is passing through our at...

Ooh, fun topic... the Sun's color that is. :) There are a number of things stated in this thread that may deserve a little more attention. I did not read every post carefully, so I am probably restating some things. The Sun has a number of colors, so one must clarify whether its true color (as seen ...

I for one don't think Old Sol quite fits the White Dwarf category; but that is my opinion. This definition of a White Dwarf doesn't sound like Sol! http://en.wikipedia.org/wiki/White_dwarf That is a great point to raise since changing the "yellow dwarf" classification -- I think "dwa...

Though this has to be the greatest visible spectrum image of the Sun, the topic of Solar color can become quite, well..., colorful. The above spectrum was created at the McMath-Pierce Solar Observatory and shows, first off, that although our yellow- appearing Sun emits light of nearly every color,.....

What a beautiful Solar image! A false color version of a false-color producing filter (H-alpha).

Reversing it makes it all that more impressive, though it isn't the best image to bring up the topic of limb darkening.

Uh oh, how do we know it crashed? What a clever way to gain a spy satellite.

The observation and drawing depict just how bright Venus is since it was seen as standing out like a "diamond" next to the bright surface of the Moon. The surface brightness of Venus is noteably brighter than the surface brightness of the Moon.

The Economist? Ug. I never did see it in Yahoo or in mainstream news. Did anyone???

I could be wrong, but wouldn't the fact that Folmhault b was imaged in 2004 count it as first? Yesterday seems to be a confirmation of that event, which I assume was earlier than the others, or was it?