APOD: A 212-Hour Exposure of Orion (2020 Mar 29)

[APOD Robot]

A 212-Hour Exposure of Orion

Explanation: The constellation of Orion is much more than three stars in a row. It is a direction in space that is rich with impressive nebulas. To better appreciate this well-known swath of sky, an extremely long exposure was taken over many clear nights in 2013 and 2014. After 212 hours of camera time and an additional year of processing, the featured 1400-exposure collage spanning over 40 times the angular diameter of the Moon emerged. Of the many interesting details that have become visible, one that particularly draws the eye is Barnard's Loop, the bright red circular filament arcing down from the middle. The Rosette Nebula is not the giant red nebula near the top of the image -- that is a larger but lesser known nebula known as Lambda Orionis. The Rosette Nebula is visible, though: it is the red and white nebula on the upper left. The bright orange star just above the frame center is Betelgeuse, while the bright blue star on the lower right is Rigel. Other famous nebulas visible include the Witch Head Nebula, the Flame Nebula, the Fox Fur Nebula, and, if you know just where to look, the comparatively small Horsehead Nebula. About those famous three stars that cross the belt of Orion the Hunter -- in this busy frame they can be hard to locate, but a discerning eye will find them just below and to the right of the image center.

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[Ann]

You haven't seen Orion until you have seen Stanislav Volskiy's portrait of Orion.

Just sayin'.

Ann

[Alex_515]

What a gorgeous image !!!

Alex

[Alex_515]

Looking the zoomed version of the image (which is really impressive...) I was wondering: take for instance Barnard's loop, you see many stars as white dot points in it. Are all these stars between us and Barnard's loop ? Or is it possible some stars are behind but we still can see them trough ?

I'm asking because it can help give a sense of depth seeing the image.

Alex.

[orin stepanek]

I keep getting ( This site can't be reached! ) I hope it comes up soon!

[Ann]

I keep getting ( This site can't be reached! ) I hope it comes up soon!

A 212-Hour Exposure of the Orion constellation. Photo: Stanislav Volskiy.

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Orion (right) and Monoceros (left). Note the abundance
of background stars in Monoceros. Photo: Alan Dyer.

I can't access the APOD either, so let's post Stanslav Volskiy's image from another source than the APOD. By the way, you can look at a large (11 MB) version of Volskiy's image here.

Alex asked if the stars that we see apparently peeking through Barnard's Loop are foreground or background stars, or if they are located right inside Barnard's Loop itself. I can't answer you, but if you scrutinize the large version of the image, you can see that the number of small stars differ in different parts of the image. One explanation is that in at least some of the areas where we see fewer stars (like, for example, to the right of Barnard's Loop), there is probably more dust that prevents us from seeing so many background stars.

This is a very deep image. We are going to see many stars that are bright and very distant, and many stars that are relatively faint and much more nearby.

You must bear in mind, too, that there are more Milky Way background stars on the left than on the right side of Stanislav Volskiy's image, because the band of the Milky Way passes through Monoceros, but hardly at all through Orion. So on the left side of the image, you are likely to see many distant Milky Way background stars, some of which may be thousands of light-years distant.

And it is possible that a non-negligent excess of background Milky Way outliers can be seen through Barnard's Loop, compared with how many background stars can be seen in the rest of Orion.

Ann

[orin stepanek]

I keep getting ( This site can't be reached! ) I hope it comes up soon!

A 212-Hour Exposure of the Orion constellation. Photo: Stanislav Volskiy.

---

Orion and Monoceros.png

Orion (right) and Monoceros (left). Note the abundance
of background stars in Monoceros. Photo: Alan Dyer.

I can't access the APOD either, so let's post Stanslav Volskiy's image from another source than the APOD. By the way, you can look at a large (11 MB) version of Volskiy's image here.

Alex asked if the stars that we see apparently peeking through Barnard's Loop are foreground or background stars, or if they are located right inside Barnard's Loop itself. I can't answer you, but if you scrutinize the large version of the image, you can see that the number of small stars differ in different parts of the image. One explanation is that in at least some of the areas where we see fewer stars (like, for example, to the right of Barnard's Loop), there is probably more dust that prevents us from seeing so many background stars.

This is a very deep image. We are going to see many stars that are bright and very distant, and many stars that are relatively faint and much more nearby.

You must bear in mind, too, that there are more Milky Way background stars on the left than on the right side of Stanislav Volskiy's image, because the band of the Milky Way passes through Monoceros, but hardly at all through Orion. So on the left side of the image, you are likely to see many distant Milky Way background stars, some of which may be thousands of light-years distant.

And it is possible that a non-negligent excess of background Milky Way outliers can be seen through Barnard's Loop, compared with how many background stars can be seen in the rest of Orion.

Ann

That I was able to get! I see I can't get any of the daily APOD's!

[orin stepanek]

Allright! Nice!

[sillyworm 2]

There is a podcast on youtube that describes the daily APODs.I found it when the APOD page would not come up earlier.

[felix_wegerer]

Wow, what a fantastic image! 212 hours is crazy. :O