Starship Asterisk*

https://www.esa.int/var/esa/storage/images/esa_multimedia/images/2018/04/gaia_s_sky_in_colour2/17475368-10-eng-GB/Gaia_s_sky_in_colour_pillars.jpg One more thing. We are used to seeing pictures of spiral galaxies where the (typically blue) arms have been made to look brighter than they are, compare...

Ann wrote: ↑Wed Dec 27, 2023 7:00 pm

The Milky Way in Sagittarius. Note the bright yellow light from the bulge of the Milky Way. It seems highly likely that this bright yellow light dominates the overall color of the Milky Way, and that the Milky Way is a relatively yellow galaxy. Credit: Terrence Dickinson.

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Ann

But what if the Milky Way in Sagittarius is in fact the core looming from both sides of the disk? It would not be fair then to attribute all that yellow to the whole galaxy

here are my 5 layman's constellations

I'm assuming that the imager's stated time of 18:52 is his local time, CST (or 17:52 UT), which is what I'm basing my calculation on. FWIW, the mountain is 70 km from the basilica, and about 3000 m higher. So there's no way at all the Moon could be 9° above the horizon. 3 km / 70 km = tg 2.5° ok, t...

after subtracting the blue shine (rgb = 45 64 91) there are some stars in the sky, probably not visible without a telescope Cathedral, Mountain, Moon-black.jpg I think the near total absence of stars is largely explained because we are looking through hundreds of kilometers of atmosphere within jus...

after subtracting the blue shine (rgb = 45 64 91) there are some stars in the sky, probably not visible without a telescope

Double checked the ephemeris. Taking the location as Turin (because it's in the list, and only a few miles away), 15 Dec 2023, 18:52 local, I get the Moon at 2° above the horizon, the Sun at 21° below the horizon, Moon at 10% waxing. I am feeling lost. Is Stellarium so unprecise? Is using "loc...

This is a 10% Moon that is 2° above the horizon. The Sun is 21° below the horizon, so just out of astronomical twilight and it should not be contributing significant light. I would be curious to know the technical details of the image. I don't think it could be achieved without some kind of HDR pro...

This is a 10% Moon that is 2° above the horizon. The Sun is 21° below the horizon, so just out of astronomical twilight and it should not be contributing significant light. I would be curious to know the technical details of the image. I don't think it could be achieved without some kind of HDR pro...

looked up 1) date and time = December 15, 2023 at 18:52 pm 2) stellarium Cathedral, Mountain, Moon..jpg Cathedral, Mountain, Moon-..jpg https://asterisk.apod.com/download/file.php?id=48994&t=1 Moon is 9° above (+09°01'15.1") and Phase=9%, Sun is 11° below (-10°55'12.6") Twilight it is

Distance. Monviso is far enough from the camera that the air scatter (chiaroscuro) between them is saturated, or nearly so. (playing the kid who could have asked the kid's question) I take it you assume that the light scattered is not coming from Moon (and this must be so seeing the shine is blue r...

why the dark blue shine of the night sky looks almost the same in front of Monviso and beside it? Distance. Monviso is far enough from the camera that the air scatter (chiaroscuro) between them is saturated, or nearly so. (playing the kid who could have asked the kid's question) I take it you assum...

kid's question: why the dark blue shine of the night sky looks almost the same in front of Monviso and beside it?

I didn't say that photons can't be affected, only that they only can travel in a straight line (geodesic) which they cannot be deviated from. Which is why scattering involves the replacement of one photon with another. So is a photon that drops in energy while traveling along a space-time geodesic ...

Elastic scattering does not result in the same photon continuing. QM describes that scattering as the annihilation of one and the creation of another. That is different from an atom absorbing a photon and emitting another. Quantum Mechanics + Quantum Field Theory may add virtual particles every way...

2) Well, sure the extra length isn't "statistically significant", but the path the reflected photon takes (ignoring particle/wave duality, etc) is certainly not shorter than the path a "direct" photon takes! And in reply to Chris, for photons being absorbed and reemitted (the &q...

A December Summer Night (2023 Dec 23)..jpgmy second question: why some 8 minute exposure arcs are thin lines but others are parallelograms? offtopic To my eye there is some resemblance between the fuzzy reflections and the the Sparkler Galaxy :wink: https://asterisk.apod.com/download/file.php?id=48...

https://asterisk.apod.com/download/file.php?id=48983&t=1 Well, if you want to be really technical, the photon that comes from Alpha Centauri never makes it to the sensor at all, regardless of the path it takes. That photon is scattered (probably many times) by air, by water, by camera optics. A...

my second question: why some 8 minute exposure arcs are thin lines but others are parallelograms?

my question: the Solar system is peculiar-moving at the speed of 20 km/s toward an apex between Lyra and Hercules.
Now does the interstellar media headwind play any part in this night sky shine? (I know this APOD says it is just Sun's stellar wind and light)

a kid's question: is the path covered by a photon from Alpha Centauri any longer if that photon is registered by the sensor in the waters' part of the scene?

Please who can make a good job of fitting MIRI to NIRCAM? https://esawebb.org/images/comparisons/weic2330/ wow Now I can fit X-ray with neutron star labelled… and it can't be seen in either NIRCAM nor MIRI :( And it is not inside the Green Monster Cas A X-.jpg Cas A MIRI-.jpg Cas A NIRCAM-.jpg X-ra...

What are the purple bubbles? Any idea? Screenshot-20231213-212535[1].png https://i.ibb.co/LSzBhCZ/Screenshot-20231213-212535.png Seems intriguing to me. JWST team writes that this circular spots is all that's left of the Green Monster's spotted skin, seen in MIRI Please who can make a good job of f...

I think that's it. I've seen plenty of nighttime pictures taken when there's a full-ish Moon, and they are indistinguishable from daytime images. so you don't think that some brownness of Moon is dimming the sky shine and therefore deepening all the shadows (in long exposure colourful nighttime sho...

offtopic about colourful scenes at night I challenge everybody to solve this mystery. If you zoom in this APOD and see just the bridge, the water and the trees, why do you still feel that it is night? There are no (sharp) shadows in the APOD, and yet the light is unevenly distributed. The bridge is...