APOD: Carina over Lake Ballard (2018 Jan 05)

[APOD Robot]

Carina over Lake Ballard

Explanation: A jewel of the southern sky, the Great Carina Nebula, also known as NGC 3372, is one of our galaxy's largest star forming regions. Easily visible to the unaided eye it stands high above the signature hill of Lake Ballard, ephemeral salt lake of Western Australia, in this serene night skyscape from December 25, 2017. The Milky Way itself stretches beyond the southern horizon. Along the Milky Way, bright stars Alpha and Beta Centauri lie just above the hill's right flank, with the Southern Cross and dark Coalsack Nebula above the hill top. Based on a 22 panel mosaic, the scene was cropped to reveal more closely the beauty of this region of the southern Milky Way. On that short summer night, a star tracking camera mount was used to record the mosaic images of the sky, but turned off to image the foreground in moonlight.

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[Boomer12k]

Way Cool... I had no idea you could see it with the naked eye... amazing...

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[BDanielMayfield]

How does the Great Carina Nebula compare to Orion, the most visible nebula of northern skies?

[Ann]

How does the Great Carina Nebula compare to Orion, the most visible nebula of northern skies?

Wikipedia wrote:

Although it is some four times as large and even brighter than the famous Orion Nebula, the Carina Nebula is much less well known due to its location in the southern sky.

Ann

[Chris Peterson]

How does the Great Carina Nebula compare to Orion, the most visible nebula of northern skies?

I find it less obvious, looking like a knot in the Milky Way, as opposed to an isolated diffuse patch. Carina is about four times brighter and twice the size, but less contrasty.

[MarkBour]

Great image, of stars and a part of the Milky Way I would not see from my home.

As an "armchair" astronomy buff, who does not have equipment and does not do such imaging, I am slowly improving in my intuitions with images such as this one. I understand that it can take considerable time for a scope or camera to gather the light to bring out an image of the sky such as this. And I don't know if there is any particular relation between the image taken of the foreground and the images of the sky features. The astrophotographer may simply choose a different amount of exposure for the foreground shot, I suppose. But it is interesting to develop some intuition about it to help in viewing such images. I did notice the foreground areas of light and shadow and guessed that this was mainly moonlight and one could determine the moon's location from the shadows. I don't know what the ground would have looked like on a dark-sky moonless night from a long exposure.

It would be nice if we could somehow teach our eyes and brains to do this. They do adjust some, and some animals are very good at night vision, but I mean if we could sit still and actually integrate like the camera does.

This is a basic technique for astronomy. I wonder are there any special applications for long exposures when imaging things on Earth?

I did google-search "long exposure photography" and got a site that (along with lots of ads, yuck) showed some fun images, though no particular applications of the technique, other than beautiful/fun images. I suppose all of the images in some sense reveal something that may not be noticed with a short exposure. https://digital-photography-school.com/ ... otography/

The Wikipedia article on Long Exposure Photography https://en.wikipedia.org/wiki/Long-exposure_photography also has some interesting examples. But I'm wondering if there are any scientific or industrial usages. The one image of insect flights in the Wikipedia article might be such a use. One can probably compute and compare speeds and other features.

Aha. Electrophoresis could be viewed as a form of long-exposure photography, and has lots of applications.

[Ann]

Mark, please note that while the Milky Way looks quite "realistic" in this picture and close to what the human eye would see, there is no way that our human eyes would see the great nebulas as intensely pink as they look in this image.

Ann

[rstevenson]

Mark, please note that while the Milky Way looks quite "realistic" in this picture and close to what the human eye would see, there is no way that our human eyes would see the great nebulas as intensely pink as they look in this image.

Ann

Nor would we see the ground looking like that in moonlight. The whole thing looks too pinkish to me. But those are the decisions the astrophotographer made, and I respect that.

Rob