M57
M57 is one of the best known objects in the late summer sky. Its distinctive and easily discernable smoke ring appearance makes it an interesting visual target, setting it apart from the usual smudge most nebulae present to the eyepiece. I venture to say there isn't a single public star party in the late summer or autumn public star party where this object is not observed.
M57 is a planetary nebula. These nebula are so named because to early telescopic astronomers their generally round shape resembled planets. Of course, they knew they weren't planets because they never moved, but the resemblance in small telescopes can be uncanny. These nebulae are actually the result of processes that occur toward the end of a star's nuclear life. If the star is too small to produce a supernova explosion, it simply runs out of fuel. As this happens, the star shrinks and actually becomes hotter in the process, thus blowing off some of its matter, producing fascinating and intricately shaped nebulae.
At first glance, M57 appears to be a relatively simple ring around a relatively bright central star. Careful photographic analysis reveals that this is anything but the case. The bright central region has a complex spiral structure that seems to be wind into a bright red oval shaped shock region. This shock wave is colliding with another fainter layer produced in an earlier weight-loss episode. This second layer has a rich structure, and itself culminates in a shock front as it collides with a very faint third layer from even earlier in the star's slow "death."
It is this third layer I wanted to capture in this image. It's very faint, and so I used longer than normal exposures to see if I could bring it out. At first I thought I had failed, but as I worked on the data I began to see that the third layer was actually there. It's not bright, even in the finished image, but there's no doubt I've captured it. It has a subtle structure that includes the remnants of a shock front that's mostly spent now. Perhaps there is another even fainter layer outside this one that's energizing this shock front. To my knowledge, nobody has ever imaged anything outside of the third layer.
In spite of it's ring-shaped appearance, it's likely this object is a barrel-shaped cylinder. From our vantage point, we are looking into the interior pretty much through the end of the barrel.
Also of note in this image is IC1296, a curiously shaped barred spiral galaxy some 220 million light years behind M57. It has one spiral arm that seems to encircle the entire galaxy, with a vestigial second arm that seems to go nowhere. It adds meaning to the scene. M57 is a single star heading toward the end of its energy production phase. IC1296 contains millions of stars at this same point in their life.
For you astrophotographers, This is 10x1200b1 luminance and 6x900b2 RGB, taken with the Twin City Amateur Astronomers - TCAA 20" Planewave over the last few months when the instrument was not otherwise engaged. While processing this data, I ran across a stack of 7 hydrogen alpha images taken with the 20" in 2014. Each is 1800 seconds long, for a total of 3.5 hours of additional imagery I could add to this one. It adds is a ton of yummy detail in the outer layers. To top it all off, I was able to locate my image from 2013 of SN2013ev, to add that detail to the image.
I have to say I'm quite surprised at how this image turned out. It far exceeds the objective I set before starting this "filler" project, and I'm very pleased with the result.
M57
M57 is one of the best known objects in the late summer sky. Its distinctive and easily discernable smoke ring appearance makes it an interesting visual target, setting it apart from the usual smudge most nebulae present to the eyepiece. I venture to say there isn't a single public star party in the late summer or autumn public star party where this object is not observed.
M57 is a planetary nebula. These nebula are so named because to early telescopic astronomers their generally round shape resembled planets. Of course, they knew they weren't planets because they never moved, but the resemblance in small telescopes can be uncanny. These nebulae are actually the result of processes that occur toward the end of a star's nuclear life. If the star is too small to produce a supernova explosion, it simply runs out of fuel. As this happens, the star shrinks and actually becomes hotter in the process, thus blowing off some of its matter, producing fascinating and intricately shaped nebulae.
At first glance, M57 appears to be a relatively simple ring around a relatively bright central star. Careful photographic analysis reveals that this is anything but the case. The bright central region has a complex spiral structure that seems to be wind into a bright red oval shaped shock region. This shock wave is colliding with another fainter layer produced in an earlier weight-loss episode. This second layer has a rich structure, and itself culminates in a shock front as it collides with a very faint third layer from even earlier in the star's slow "death."
It is this third layer I wanted to capture in this image. It's very faint, and so I used longer than normal exposures to see if I could bring it out. At first I thought I had failed, but as I worked on the data I began to see that the third layer was actually there. It's not bright, even in the finished image, but there's no doubt I've captured it. It has a subtle structure that includes the remnants of a shock front that's mostly spent now. Perhaps there is another even fainter layer outside this one that's energizing this shock front. To my knowledge, nobody has ever imaged anything outside of the third layer.
In spite of it's ring-shaped appearance, it's likely this object is a barrel-shaped cylinder. From our vantage point, we are looking into the interior pretty much through the end of the barrel.
Also of note in this image is IC1296, a curiously shaped barred spiral galaxy some 220 million light years behind M57. It has one spiral arm that seems to encircle the entire galaxy, with a vestigial second arm that seems to go nowhere. It adds meaning to the scene. M57 is a single star heading toward the end of its energy production phase. IC1296 contains millions of stars at this same point in their life.
For you astrophotographers, This is 10x1200b1 luminance and 6x900b2 RGB, taken with the Twin City Amateur Astronomers - TCAA 20" Planewave over the last few months when the instrument was not otherwise engaged. While processing this data, I ran across a stack of 7 hydrogen alpha images taken with the 20" in 2014. Each is 1800 seconds long, for a total of 3.5 hours of additional imagery I could add to this one. It adds is a ton of yummy detail in the outer layers. To top it all off, I was able to locate my image from 2013 of SN2013ev, to add that detail to the image.
I have to say I'm quite surprised at how this image turned out. It far exceeds the objective I set before starting this "filler" project, and I'm very pleased with the result.