Starship Asterisk*

A February Moon Halo

Explanation: Lighting the night last Tuesday, February's Full Moon is sometimes called the Snow Moon. But the Moon was not quite full in this mosaicked skyscape recorded on February 2 south of Budapest, Hungary, and there was no snow either. Still, thin clouds of ice crystals hung in the cold, wintry sky creating this gorgeous lunar halo. Refraction of moonlight by the six-sided crystals produce the slightly colored halo with its characteristic radius of 22 degrees. Just below the Moon is bright star Aldebaran. Also well within the halo at the right is the Pleiades star cluster. At the lower left, near the halo's edge lie the stars of Orion with bright Capella, alpha star of the constellation Auriga, just beyond the halo near the top of the frame.

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Halo moon, how ya doin'?

This I like a lot!

Beautifully composed and framed, it also includes my favourite constellation!

I agree. It's fun to pick out the constellations peeking through the milky light of this mighty "halo Moon". The tree looks good, too.

Ann

Nice shot. Just curious, but what's that ~2nd mag object a close five o'clock from Bellatrix? All the other faint objects in the image correspond to known stars and there are no other processing artefacts visible.

I've seen Moon Halos and this photo is really a pleasant reminder. The tree sets it off nicely!

WOW ~~ what a spectacular scene ~~ beautiful photo!

von fonebone wrote:Nice shot. Just curious, but what's that ~2nd mag object a close five o'clock from Bellatrix? All the other faint objects in the image correspond to known stars and there are no other processing artefacts visible.

I was wondering the same thing.

Ann

von fonebone wrote:Nice shot. Just curious, but what's that ~2nd mag object a close five o'clock from Bellatrix? All the other faint objects in the image correspond to known stars and there are no other processing artefacts visible.

I just wondered the same. Who will answer?

von fonebone wrote:Nice shot. Just curious, but what's that ~2nd mag object a close five o'clock from Bellatrix? All the other faint objects in the image correspond to known stars and there are no other processing artefacts visible.

Hard to say for sure without access to the original image or images, but it's most likely just a hot pixel- not uncommon in images like this. In this region of the sky, a geosynchronous satellite is also a possibility- something that probably wouldn't have moved enough in a few seconds to show blurring. This could be checked if the exact time of the image were known.

The incorrect location of Betelgeuse alerted me to look more carefully at this image. The key is that the caption states that this is a mosaic, and that explains the peculiarities - the stitching together of the images isn't perfect, and so Betelgeuse is not where it should be. Also, as others have already noticed, there is a second bright star next to Bellatrix. I believe this is just Belatrix again, and it shows up twice in the
mosaic because of imperfect registration of the individual images. It is a shame that it isn't quite correct, as otherwise it is a very nice image.

genghis wrote:The incorrect location of Betelgeuse alerted me to look more carefully at this image. The key is that the caption states that this is a mosaic, and that explains the peculiarities - the stitching together of the images isn't perfect, and so Betelgeuse is not where it should be. Also, as others have already noticed, there is a second bright star next to Bellatrix. I believe this is just Belatrix again, and it shows up twice in the
mosaic because of imperfect registration of the individual images. It is a shame that it isn't quite correct, as otherwise it is a very nice image.

Very plausible. It is hard to mosaic wide field shots made with camera lenses, because the image scale varies with distance from the optical center. That means quite a lot of distortion must be removed during the stacking, which requires specialized software.

I also noticed that there must be some distortion in the scaling of the image (maybe due to the mosiac-ing of the image that others have discussed) because the radius of the halo is 22 degrees, but the radius of the moon is about 1/4 degree. So, in just eyeballing the picture, these proportions don't seem to apply (the moon seems larger than 1/4 degree radius if the halo is 22 degrees radius), and there must be some "fisheye" lensing going on here. That's not a criticism, just an observation.

Nice one. Mosaics seem difficult to photograph and comes with many difficulties, especially the placement of stars such as Betelgeuse and the duplication of them like Bellatrix.

Guest wrote:
I also noticed that there must be some distortion in the scaling of the image (maybe due to the mosiac-ing of the image that others have discussed) because the radius of the halo is 22 degrees, but the radius of the moon is about 1/4 degree. So, in just eyeballing the picture, these proportions don't seem to apply (the moon seems larger than 1/4 degree radius if the halo is 22 degrees radius), and there must be some "fisheye" lensing going on here. That's not a criticism, just an observation.

The Moon is way overexposed.

Overexposed Betelgeuse also shows up as multiple pixels.

Oh darn. I was really enjoying this image until I read all the nitpicking comments. But I guess if you have nits it's helpful to have a friend pick them out of your hair. Seriously, this is a beautiful image. I love looking at the night sky during every phase of the moon and all kinds of weather. Sure, you want a clear, dark, moonless sky to observe faint deep sky objects, but the sky always has something unique to show us, if we care to look closely. Sometimes it's just the mother-of-pearl glow of moonlight through the clouds ... .