Starship Asterisk*

Google Translate wrote:A beautiful image of the Moon Halo in winter, congratulations!

Chris Peterson wrote:

RedFishBlueFish wrote:What is the bright blue spot in Orion, just outside the inner halo at about 5 o'clock: UFO, Healing Brush gone wrong, or some sort of reflection within the lens?

It appears to be an internal reflection. I see a subtle hexagonal structure aligned with the lunar diffraction spikes, created by the 6-leaf iris in this lens.

ronboy wrote:
A lunar Halo = What Neil Armstrong "really" said first.

http://en.wikipedia.org/wiki/Hello wrote:
<<Hello, with that spelling, was used in publications as early as 1833.

According to the Oxford English Dictionary, hello is an alteration of hallo, hollo,
which came from Old High German "halâ, holâ, emphatic imperative of halôn,
holôn to fetch, used especially in hailing a ferryman.">>

• • Twelfth Night Act 1, Scene 5
  
  VIOLA: Make me a willow cabin at your gate,
  • And call upon my soul within the house;
    Write loyal cantons of contemned love
    And sing them loud even in the dead of night;
    Halloo your name to the reverberate hills
    And make the babbling gossip of the air
    Cry out 'Olivia!' O, You should not rest
    Between the elements of air and earth,
    But you should pity me!

ronboy wrote:A lunar Halo = What Neil Armstrong "really" said first.

Chris Peterson wrote:

florid_snow wrote:
Getting corrected by Chris is like a dream come true, I always appreciate reading your clear comments on here.

Thanks... but you made me spit my coffee onto my keyboard when I saw that!

Chris Peterson wrote:

Indigo_Sunrise wrote:Can someone please explain the difference between the '46* halo' and the 'infralateral arc'?
In that image, they look like they are part of the same halo/arc....

The two are formed by different mechanisms. By all accounts, they can be difficult to distinguish from each other, and are easily confused. There's some good information here.

The lower colourful halo some 46° below the sun is an infralateral or circumhorizon arc. Note the greens and blues which would not be present in a 46° halo.

Chris Peterson wrote:

orin stepanek wrote:Interesting photo; but was the fish-eye lens necessary to capture the view? I think it could be a beautiful photo if done with regular photography! Just MHO!

A 46° halo is specified by its radius. In other words, just capturing it completely (which this image does not) requires a vertical field of view of 92°, which (given typical image aspect ratios) means a horizontal FOV of 140°. That requires what is commonly called an ultra wide angle lens, which is probably what was used for this image (not a fisheye).

orin stepanek wrote:Interesting photo; but was the fish-eye lens necessary to capture the view? I think it could be a beautiful photo if done with regular photography! Just MHO!

florid_snow wrote:Getting corrected by Chris is like a dream come true, I always appreciate reading your clear comments on here.

Chris Peterson wrote:

florid_snow wrote:Then the 46 degree halo, more often called the circum-horizontal arc

The 46° halo and circumhorizontal (or circumhorizon) arcs are different phenomena. They are not synonymous.

JohnD wrote:postscript.
I've seen the link from Chris: http://www.atoptics.co.uk/halo/46orsup.htm and am even less convinced that it is a circumscribed halo we see.
In the link's pics, those are a defined arc which, er, arc away from the internal halo, like an astrological Mercury sign.
John

florid_snow wrote:Then the 46 degree halo, more often called the circum-horizontal arc

JohnD wrote:

owlice wrote:

JohnD wrote:Four rainbows?

I can see a complete circle around the Moon, and an arc between it and the horizon.
Where are the other two?

John

Four halos, not rainbows. Please see this image, to which the text links, for a labelled version.

Thnaks, Owlice, but unconvincing.

The inner halo (apologies) is labelled both 22degrees and Circumscribed, and the outer arc the 46 degree halo and the infralateral arc.
That is astronomical legerdemain!
Nothing up my sleeves! Look! Abracadabra! Two haloes become ......... Four haloes!


But re-reading the original description, I note "Elongating the 22 degree arc horizontally is a circumscribed halo" Is this the tangential array touching the 22 halo at approx four oclock, and spreading outwards? I took that for very high cloud. Which I suppose it is, but as such unremarkable.
And the "(third) rainbow-like arc 46 degrees from the Moon and appearing here just above a picturesque winter landscape" is paired with "part of a whole 46 degree circular halo is also visible" as the fourth halo. Two for the price of one - a bargain!

I'm glad to accept if you say so, that the tangential cloud is the second halo. A straight, not round halo, but anyway.

And that two different sorts of ice crystals can cause different effects, with the same "distant tumbling ice crystals" cause the third and fourth haloes? In the same relationship around the Moon, so it's difficult to accept that this is more than one phenomenon, a total of three haloes. Remarkable enough by themselves, but please explain further why four - I'll be most grateful.

John

owlice wrote:

JohnD wrote:Four rainbows?

I can see a complete circle around the Moon, and an arc between it and the horizon.
Where are the other two?

John

Four halos, not rainbows. Please see this image, to which the text links, for a labelled version.