APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

Post a reply


This question is a means of preventing automated form submissions by spambots.
Smilies
:D :) :ssmile: :( :o :shock: :? 8-) :lol2: :x :P :oops: :cry: :evil: :roll: :wink: :!: :?: :idea: :arrow: :| :mrgreen:
View more smilies

BBCode is ON
[img] is ON
[url] is ON
Smilies are ON

Topic review
   

Expand view Topic review: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by chadleader » Thu Oct 31, 2024 12:18 pm

Ann wrote: Thu Oct 31, 2024 5:31 am

Thanks so much, Chad, for your explanation!

You explained why your old image looks the way it does, but you also explained why the APOD editors wanted it. It is, frankly, because it looks spooky, and this is Halloween week.

Tao made the perfect comment on why the APOD editors wanted your picture:

Image Image


And I can see that Pferkul made a similar observation:


I checked out your websites, and your later work is something else entirely. Just as an example, this is your beautiful portrait of Andromeda:


nfFdhj2_pfu6_1824x0_n1wMX-gx[1].jpg


Ann
Thanks for taking the time, Ann. Yes - the spooky vibe and resemblance to Halloween characters is exactly the reason the image was selected.

My opinion is that APOD isn't a contest of technical ability. Sometimes an image is just interesting, different, or unique in some way. The editors have every right to select images that meet that criteria (or whatever criteria they want). It's not their job to "set a standard" in the hobby, as some have alluded to. If that were the case, the only images featured would be from Hubble, JWST, remote observatories and those who own $50,000 telescopes in bortle 1 skies. I quite like seeing amateur images on APOD, knowing someone overcame light pollution, modest gear limitations and processing challenges to create a beautiful image.

Anyway, hopefully case closed :lol2: Happy Halloween!

Chad

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by Ann » Thu Oct 31, 2024 5:31 am

Guest wrote: Thu Oct 31, 2024 12:43 am Hi everyone,

I really appreciate this conversation. As the owner of the image, please allow me to provide some information and clarity on the situation.

This photo was taken in July of 2020 (over four years ago), when I had less than one of year of astrophotography experience. I submitted it to APOD around that same time, and they decided to publish it just now.

Before you criticize too harshly - think about how much you've learned about astrophotography in the last four years, and how much the equipment and software has evolved in that time. I was a beginner, with a dream of winning an APOD - so I collected some data with my 8" SCT from a bortle 9 sky in Washington DC, and processed it to DEATH. Yes, that's right - I wanted to squeeze every little detail out of this data that I could. In doing so, I over processed it. I destroyed the data with deconvolution and sharpening tools from multiple applications. To my inexperienced eyes, it looked really cool. And, at the time, there were lots of FB and IG astrophotographers processing their images this way. I've grown a lot in the hobby since that time.

When the nice folks at APOD reached out to me last week about this image being selected, I offered up a newer SHO version of the Bubble Nebula I took in 2021 to replace it - but they opted to keep the older version. I respect their decision, as it is ultimately their website and their subjective eyes as to what deserves to be an APOD. I was still very honored any image of mine was selected, old or new.

I knew the harsh processing and artifacts would bring out the AP police - and maybe rightly so. There's a school of AP-ers out there that are "purists", and hold other hobbyists accountable when it comes to being "overly-subjective" during the processing of data. This is not necessarily a bad thing. At the same time, all of us take liberties with color, sharpness, noise reduction, brightness, etc. with every single image. There's a fine line there, one which ALL of us are guilty of crossing. My current philosophy is somewhere in the middle. I like to take some liberties, but I also want to respect the data.

Would I process this data the same way now, more than 4 years later? Absolutely not. Am I proud of this image? Yes - it's a reminder of how far I've come, and a reminder to not be so harsh with others' subjective decisions on how they process their own images. When I look at this old image, I still feel something and see an interesting and beautiful astronomical object. Selfishly, that's really all that matters to me. And if it makes other people feel something similar, then that's great too.

I invite you to check out my astrobin https://www.astrobin.com/users/chadleader/ and website: https://www.ancientphotonsastro.com/. I really love the hobby and want to respect it. I realize this APOD is not a popular one amongst many of the heavy hitters of astrophotography. But, hopefully reading this will provide some context and perspective.

Thanks, and clear skies to you all. I look forward to seeing many of your images as APODs some time soon, and maybe if I'm lucky enough, I'll snag another in the future as well.

Chad
Thanks so much, Chad, for your explanation!

You explained why your old image looks the way it does, but you also explained why the APOD editors wanted it. It is, frankly, because it looks spooky, and this is Halloween week.

Tao made the perfect comment on why the APOD editors wanted your picture:

Image Image


And I can see that Pferkul made a similar observation:


I checked out your websites, and your later work is something else entirely. Just as an example, this is your beautiful portrait of Andromeda:

nfFdhj2_pfu6_1824x0_n1wMX-gx[1].jpg

Ann

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by Chris Peterson » Thu Oct 31, 2024 3:41 am

chadleader wrote: Thu Oct 31, 2024 3:11 am
Chris Peterson wrote: Thu Oct 31, 2024 1:56 am
chadleader wrote: Thu Oct 31, 2024 1:37 am
Hi Chris - I believe I have the old master file on an old hard drive. I'll check tomorrow and see. That's a good idea - I haven't worked with OSC data in a while, so it'll be fun to see what these new tools can do with that type of data. A lot has changed in the last four years!

FYI, for anybody who's curious: the image was taken with an Edge HD 8 and a ZWO ASI533MC Pro with a dual band filter (L-eNhance). Still have the Edge, not the camera.
An example, quite relevant to today's APOD: data taken in 2002 with an ST8i camera on a 12" LX200, 30 15-second frames. First image processed at the time, second image processed earlier this year. Exactly the same source data. (Second image is twice the size because I used drizzle processing.)
_
NGC7635_2002.jpg
NGC7635_2024.jpg
Huge difference, and an excellent demonstration! Thanks for sharing. I should probably go through a lot of my old data and take a look with fresh eyes and updated tools / skills. You must’ve been thrilled to get that image back in 2002.
I sure was!

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by chadleader » Thu Oct 31, 2024 3:11 am

Chris Peterson wrote: Thu Oct 31, 2024 1:56 am
chadleader wrote: Thu Oct 31, 2024 1:37 am
Hi Chris - I believe I have the old master file on an old hard drive. I'll check tomorrow and see. That's a good idea - I haven't worked with OSC data in a while, so it'll be fun to see what these new tools can do with that type of data. A lot has changed in the last four years!

FYI, for anybody who's curious: the image was taken with an Edge HD 8 and a ZWO ASI533MC Pro with a dual band filter (L-eNhance). Still have the Edge, not the camera.
An example, quite relevant to today's APOD: data taken in 2002 with an ST8i camera on a 12" LX200, 30 15-second frames. First image processed at the time, second image processed earlier this year. Exactly the same source data. (Second image is twice the size because I used drizzle processing.)
_
NGC7635_2002.jpg
NGC7635_2024.jpg
Huge difference, and an excellent demonstration! Thanks for sharing. I should probably go through a lot of my old data and take a look with fresh eyes and updated tools / skills. You must’ve been thrilled to get that image back in 2002.

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by Chris Peterson » Thu Oct 31, 2024 1:56 am

chadleader wrote: Thu Oct 31, 2024 1:37 am
Hi Chris - I believe I have the old master file on an old hard drive. I'll check tomorrow and see. That's a good idea - I haven't worked with OSC data in a while, so it'll be fun to see what these new tools can do with that type of data. A lot has changed in the last four years!

FYI, for anybody who's curious: the image was taken with an Edge HD 8 and a ZWO ASI533MC Pro with a dual band filter (L-eNhance). Still have the Edge, not the camera.
An example, quite relevant to today's APOD: data taken in 2002 with an ST8i camera on a 12" LX200, 30 15-second frames. First image processed at the time, second image processed earlier this year. Exactly the same source data. (Second image is twice the size because I used drizzle processing.)
_
NGC7635_2002.jpg
NGC7635_2024.jpg

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by chadleader » Thu Oct 31, 2024 1:37 am

Chris Peterson wrote: Thu Oct 31, 2024 1:06 am
Guest wrote: Thu Oct 31, 2024 12:43 am Hi everyone,

I really appreciate this conversation. As the owner of the image, please allow me to provide some information and clarity on the situation.

This photo was taken in July of 2020 (over four years ago), when I had less than one of year of astrophotography experience. I submitted it to APOD around that same time, and they decided to publish it just now.

Before you criticize too harshly - think about how much you've learned about astrophotography in the last four years, and how much the equipment and software has evolved in that time. I was a beginner, with a dream of winning an APOD - so I collected some data with my 8" SCT from a bortle 9 sky in Washington DC, and processed it to DEATH. Yes, that's right - I wanted to squeeze every little detail out of this data that I could. In doing so, I over processed it. I destroyed the data with deconvolution and sharpening tools from multiple applications. To my inexperienced eyes, it looked really cool. And, at the time, there were lots of FB and IG astrophotographers processing their images this way. I've grown a lot in the hobby since that time.

When the nice folks at APOD reached out to me last week about this image being selected, I offered up a newer SHO version of the Bubble Nebula I took in 2021 to replace it - but they opted to keep the older version. I respect their decision, as it is ultimately their website and their subjective eyes as to what deserves to be an APOD. I was still very honored any image of mine was selected, old or new.

I knew the harsh processing and artifacts would bring out the AP police - and maybe rightly so. There's a school of AP-ers out there that are "purists", and hold other hobbyists accountable when it comes to being "overly-subjective" during the processing of data. This is not necessarily a bad thing. At the same time, all of us take liberties with color, sharpness, noise reduction, brightness, etc. with every single image. There's a fine line there, one which ALL of us are guilty of crossing. My current philosophy is somewhere in the middle. I like to take some liberties, but I also want to respect the data.

Would I process this data the same way now, more than 4 years later? Absolutely not. Am I proud of this image? Yes - it's a reminder of how far I've come, and a reminder to not be so harsh with others' subjective decisions on how they process their own images. When I look at this old image, I still feel something and see an interesting and beautiful astronomical object. Selfishly, that's really all that matters to me. And if it makes other people feel something similar, then that's great too.

I invite you to check out my astrobin https://www.astrobin.com/users/chadleader/ and website: https://www.ancientphotonsastro.com/. I really love the hobby and want to respect it. I realize this APOD is not a popular one amongst many of the heavy hitters of astrophotography. But, hopefully reading this will provide some context and perspective.

Thanks, and clear skies to you all. I look forward to seeing many of your images as APODs some time soon, and maybe if I'm lucky enough, I'll snag another in the future as well.

Chad
Do you have the original subs and calibration images? If so, you ought to reprocess them. I've reprocessed images I took more than 20 years ago, with my current experience and much better processing tools. The results can be amazing!
Hi Chris - I believe I have the old master file on an old hard drive. I'll check tomorrow and see. That's a good idea - I haven't worked with OSC data in a while, so it'll be fun to see what these new tools can do with that type of data. A lot has changed in the last four years!

FYI, for anybody who's curious: the image was taken with an Edge HD 8 and a ZWO ASI533MC Pro with a dual band filter (L-eNhance). Still have the Edge, not the camera.

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by Chris Peterson » Thu Oct 31, 2024 1:06 am

Guest wrote: Thu Oct 31, 2024 12:43 am Hi everyone,

I really appreciate this conversation. As the owner of the image, please allow me to provide some information and clarity on the situation.

This photo was taken in July of 2020 (over four years ago), when I had less than one of year of astrophotography experience. I submitted it to APOD around that same time, and they decided to publish it just now.

Before you criticize too harshly - think about how much you've learned about astrophotography in the last four years, and how much the equipment and software has evolved in that time. I was a beginner, with a dream of winning an APOD - so I collected some data with my 8" SCT from a bortle 9 sky in Washington DC, and processed it to DEATH. Yes, that's right - I wanted to squeeze every little detail out of this data that I could. In doing so, I over processed it. I destroyed the data with deconvolution and sharpening tools from multiple applications. To my inexperienced eyes, it looked really cool. And, at the time, there were lots of FB and IG astrophotographers processing their images this way. I've grown a lot in the hobby since that time.

When the nice folks at APOD reached out to me last week about this image being selected, I offered up a newer SHO version of the Bubble Nebula I took in 2021 to replace it - but they opted to keep the older version. I respect their decision, as it is ultimately their website and their subjective eyes as to what deserves to be an APOD. I was still very honored any image of mine was selected, old or new.

I knew the harsh processing and artifacts would bring out the AP police - and maybe rightly so. There's a school of AP-ers out there that are "purists", and hold other hobbyists accountable when it comes to being "overly-subjective" during the processing of data. This is not necessarily a bad thing. At the same time, all of us take liberties with color, sharpness, noise reduction, brightness, etc. with every single image. There's a fine line there, one which ALL of us are guilty of crossing. My current philosophy is somewhere in the middle. I like to take some liberties, but I also want to respect the data.

Would I process this data the same way now, more than 4 years later? Absolutely not. Am I proud of this image? Yes - it's a reminder of how far I've come, and a reminder to not be so harsh with others' subjective decisions on how they process their own images. When I look at this old image, I still feel something and see an interesting and beautiful astronomical object. Selfishly, that's really all that matters to me. And if it makes other people feel something similar, then that's great too.

I invite you to check out my astrobin https://www.astrobin.com/users/chadleader/ and website: https://www.ancientphotonsastro.com/. I really love the hobby and want to respect it. I realize this APOD is not a popular one amongst many of the heavy hitters of astrophotography. But, hopefully reading this will provide some context and perspective.

Thanks, and clear skies to you all. I look forward to seeing many of your images as APODs some time soon, and maybe if I'm lucky enough, I'll snag another in the future as well.

Chad
Do you have the original subs and calibration images? If so, you ought to reprocess them. I've reprocessed images I took more than 20 years ago, with my current experience and much better processing tools. The results can be amazing!

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by Guest » Thu Oct 31, 2024 12:43 am

Hi everyone,

I really appreciate this conversation. As the owner of the image, please allow me to provide some information and clarity on the situation.

This photo was taken in July of 2020 (over four years ago), when I had less than one of year of astrophotography experience. I submitted it to APOD around that same time, and they decided to publish it just now.

Before you criticize too harshly - think about how much you've learned about astrophotography in the last four years, and how much the equipment and software has evolved in that time. I was a beginner, with a dream of winning an APOD - so I collected some data with my 8" SCT from a bortle 9 sky in Washington DC, and processed it to DEATH. Yes, that's right - I wanted to squeeze every little detail out of this data that I could. In doing so, I over processed it. I destroyed the data with deconvolution and sharpening tools from multiple applications. To my inexperienced eyes, it looked really cool. And, at the time, there were lots of FB and IG astrophotographers processing their images this way. I've grown a lot in the hobby since that time.

When the nice folks at APOD reached out to me last week about this image being selected, I offered up a newer SHO version of the Bubble Nebula I took in 2021 to replace it - but they opted to keep the older version. I respect their decision, as it is ultimately their website and their subjective eyes as to what deserves to be an APOD. I was still very honored any image of mine was selected, old or new.

I knew the harsh processing and artifacts would bring out the AP police - and maybe rightly so. There's a school of AP-ers out there that are "purists", and hold other hobbyists accountable when it comes to being "overly-subjective" during the processing of data. This is not necessarily a bad thing. At the same time, all of us take liberties with color, sharpness, noise reduction, brightness, etc. with every single image. There's a fine line there, one which ALL of us are guilty of crossing. My current philosophy is somewhere in the middle. I like to take some liberties, but I also want to respect the data.

Would I process this data the same way now, more than 4 years later? Absolutely not. Am I proud of this image? Yes - it's a reminder of how far I've come, and a reminder to not be so harsh with others' subjective decisions on how they process their own images. When I look at this old image, I still feel something and see an interesting and beautiful astronomical object. Selfishly, that's really all that matters to me. And if it makes other people feel something similar, then that's great too.

I invite you to check out my astrobin https://www.astrobin.com/users/chadleader/ and website: https://www.ancientphotonsastro.com/. I really love the hobby and want to respect it. I realize this APOD is not a popular one amongst many of the heavy hitters of astrophotography. But, hopefully reading this will provide some context and perspective.

Thanks, and clear skies to you all. I look forward to seeing many of your images as APODs some time soon, and maybe if I'm lucky enough, I'll snag another in the future as well.

Chad

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by Chris Peterson » Wed Oct 30, 2024 11:07 pm

gorante wrote: Wed Oct 30, 2024 9:42 pm I don't know the history of this image, but I think it is exactly what should NEVER be awarded an APOD.

Aside from the shape of the bubble, there is not a single detail that is real, there is no match with the details visible in the Hubble version.

Here is a simple comparison:
Click to play embedded YouTube video.
two_bubbles.jpg



I don't want to be mean or overly critical, but for all the good amateur astronomical photos, this is really the last image I would ever publish.
That's a bit extreme. Most everything in the APOD roughly corresponds to structure visible in the HST image. But at the fine scale, much less than the seeing-limited resolution, the deconvolution tool created a lot of artifacts. This is sort of the imaging equivalent of multiplying a couple of numbers with two decimal precision together and then claiming some significance to your result out to a dozen places.

It is worth noting that the HST image is narrowband SHO, while today's APOD appears to be RGB or HRGB, so some variation is to be expected.

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by gorante » Wed Oct 30, 2024 9:42 pm

I don't know the history of this image, but I think it is exactly what should NEVER be awarded an APOD.

Aside from the shape of the bubble, there is not a single detail that is real, there is no match with the details visible in the Hubble version.

Here is a simple comparison:
Click to play embedded YouTube video.
two_bubbles.jpg


I don't want to be mean or overly critical, but for all the good amateur astronomical photos, this is really the last image I would ever publish.

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by AVAO » Wed Oct 30, 2024 8:33 pm

johnnydeep wrote: Wed Oct 30, 2024 8:14 pm
AVAO wrote: Wed Oct 30, 2024 8:11 pm
johnnydeep wrote: Wed Oct 30, 2024 7:27 pm

Well, I did say that it was "refined" in some way. But Chad Leader is the author of both, that's for certain! I eagerly anticipate AVAO's excellent mouse-over work comparing the two.
ThanX Johnny 4 the suggestion for teamwork :wink:
Click to view full size image 1 or image 2
Copyrights: Chad Leader
Sweet! So what's your verdict - is it the same image, though processed in still unknown ways, or not?
Good question. The image alignment was only shifted by under one percent,
which is already suspicious. I would assume it was a well-intentioned Halloween joke,
to demonstrate what is possible with long exposure (wide stars) & AI (hyperrealistic structures).

But maybe the creator of the work is reading our discussion and would like to have his say?

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by AVAO » Wed Oct 30, 2024 8:18 pm

Ann wrote: Wed Oct 30, 2024 7:46 am
And bubbles, or rings, appear in unexpected places.
Ann

Well spoken. I also like rings .-)
Click to view full size image 1 or image 2
Original data: NASA/ESA (GLIMPSE/WISE)


R Aquarii I like too... (wikipedia)
https://www.youtube.com/watch?v=cT8ISvc7mxs

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by johnnydeep » Wed Oct 30, 2024 8:14 pm

AVAO wrote: Wed Oct 30, 2024 8:11 pm
johnnydeep wrote: Wed Oct 30, 2024 7:27 pm
Ann wrote: Wed Oct 30, 2024 7:25 pm

I don't think the APOD looks much like the image by Chad Leader that you posted, Johnny:


Ann
Well, I did say that it was "refined" in some way. But Chad Leader is the author of both, that's for certain! I eagerly anticipate AVAO's excellent mouse-over work comparing the two.
ThanX Johnny 4 the suggestion for teamwork :wink:
Click to view full size image 1 or image 2
Copyrights: Chad Leader
Sweet! So what's your verdict - is it the same image, though processed in still unknown ways, or not?

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by AVAO » Wed Oct 30, 2024 8:11 pm

johnnydeep wrote: Wed Oct 30, 2024 7:27 pm
Ann wrote: Wed Oct 30, 2024 7:25 pm
johnnydeep wrote: Wed Oct 30, 2024 7:04 pm
I think the image is from this one, altered or not I'm not sure [ EDIT: ok, yes, the image is refined in some way for the APOD ]:

Found on https://www.astrobin.com/users/chadleader
I don't think the APOD looks much like the image by Chad Leader that you posted, Johnny:


Ann
Well, I did say that it was "refined" in some way. But Chad Leader is the author of both, that's for certain! I eagerly anticipate AVAO's excellent mouse-over work comparing the two.
ThanX Johnny 4 the suggestion for teamwork :wink:
Click to view full size image 1 or image 2
Copyrights: Chad Leader
Attachments
Unbenannt-26.jpg

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by pferkul » Wed Oct 30, 2024 8:05 pm

Right: A Melkotian from the original Star Trek series (Spectre of the Gun)
Attachments
Melkotian-ST.jpg

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by johnnydeep » Wed Oct 30, 2024 7:27 pm

Ann wrote: Wed Oct 30, 2024 7:25 pm
johnnydeep wrote: Wed Oct 30, 2024 7:04 pm
I think the image is from this one, altered or not I'm not sure [ EDIT: ok, yes, the image is refined in some way for the APOD ]:

Found on https://www.astrobin.com/users/chadleader
I don't think the APOD looks much like the image by Chad Leader that you posted, Johnny:


Ann
Well, I did say that it was "refined" in some way. But Chad Leader is the author of both, that's for certain! I eagerly anticipate AVAO's excellent mouse-over work comparing the two.

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by Ann » Wed Oct 30, 2024 7:25 pm

johnnydeep wrote: Wed Oct 30, 2024 7:04 pm
I think the image is from this one, altered or not I'm not sure [ EDIT: ok, yes, the image is refined in some way for the APOD ]:

Found on https://www.astrobin.com/users/chadleader
I don't think the APOD looks much like the image by Chad Leader that you posted, Johnny:


Ann

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by johnnydeep » Wed Oct 30, 2024 7:04 pm

AVAO wrote: Wed Oct 30, 2024 5:55 pm
Chris Peterson wrote: Wed Oct 30, 2024 2:43 pm This image displays a disturbing trend in some astroimaging these days of overprocessing to the point that structure is invented. We only need to look at the size of the stars to see that seeing conditions were limited to about 2 arcseconds. All that fine detail inside the nebula was synthesized by deconvolution techniques... and it's apparent that much of it is inaccurate. Compare an image I made that has almost exactly the same star sizes as today's APOD, and compare both with a Hubble image. I'm not buying that today's image has more detail than the HST could recover! And there's clearly structure in today's image that doesn't exist in the genuinely high resolution Hubble image. (And note that the HST star sizes are consistent with the detail in the fine structure.)
_
bubble_clp.jpg
bubble_leader.jpg
bubble_hst.jpg

I completely agree with your opinion, even though a synthetic zombie APOD fits this week's topic perfectly :evil: . What irritates me a little is the fact that the APOD image shown cannot be found anywhere else on the internet, so there is no information on how the fine structures were created. This surprises me, because Chad Leader is one of the professionals.

https://www.ancientphotonsastro.com/photo-gallery
https://www.youtube.com/@ancientphotonsastrophotogr6999

Your own image is probably one of the very best that I have ever seen on Earth.

When zoomed in, it shows the inside of the bubble in all its three-dimensionality.
What you see inside is a jumble of snake-like filament strands.
Interestingly, in IR you can see their continuation also OUTSIDE the bubble.
Click to view full size image 1 or image 2
Original data: NASA/ESA (HST/SST) jac berne (flickr)
I think the image is from this one, altered or not I'm not sure [ EDIT: ok, yes, the image is refined in some way for the APOD ]:

Found on https://www.astrobin.com/users/chadleader

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by AVAO » Wed Oct 30, 2024 5:55 pm

Chris Peterson wrote: Wed Oct 30, 2024 2:43 pm This image displays a disturbing trend in some astroimaging these days of overprocessing to the point that structure is invented. We only need to look at the size of the stars to see that seeing conditions were limited to about 2 arcseconds. All that fine detail inside the nebula was synthesized by deconvolution techniques... and it's apparent that much of it is inaccurate. Compare an image I made that has almost exactly the same star sizes as today's APOD, and compare both with a Hubble image. I'm not buying that today's image has more detail than the HST could recover! And there's clearly structure in today's image that doesn't exist in the genuinely high resolution Hubble image. (And note that the HST star sizes are consistent with the detail in the fine structure.)
_
bubble_clp.jpg
bubble_leader.jpg
bubble_hst.jpg

I completely agree with your opinion, even though a synthetic zombie APOD fits this week's topic perfectly :evil: . What irritates me a little is the fact that the APOD image shown cannot be found anywhere else on the internet, so there is no information on how the fine structures were created. This surprises me, because Chad Leader is one of the professionals.

https://www.ancientphotonsastro.com/photo-gallery
https://www.youtube.com/@ancientphotonsastrophotogr6999

Your own image is probably one of the very best that I have ever seen on Earth.

When zoomed in, it shows the inside of the bubble in all its three-dimensionality.
What you see inside is a jumble of snake-like filament strands.
Interestingly, in IR you can see their continuation also OUTSIDE the bubble.
Click to view full size image 1 or image 2
Original data: NASA/ESA (HST/SST) jac berne (flickr)

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by zendae » Wed Oct 30, 2024 3:39 pm

So why would the astroimagers do that? Does it in some way contribute to data which may verify the reason for it? Or is it just boys playing in a sandbox?

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by HunterofPhotons » Wed Oct 30, 2024 3:34 pm

Today is a sad day.
Presenting badly manipulated data as reality isn't cool.
APOD has been a hallmark of quality, let's keep it that way.

dan kowall

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by Chris Peterson » Wed Oct 30, 2024 2:43 pm

This image displays a disturbing trend in some astroimaging these days of overprocessing to the point that structure is invented. We only need to look at the size of the stars to see that seeing conditions were limited to about 2 arcseconds. All that fine detail inside the nebula was synthesized by deconvolution techniques... and it's apparent that much of it is inaccurate. Compare an image I made that has almost exactly the same star sizes as today's APOD, and compare both with a Hubble image. I'm not buying that today's image has more detail than the HST could recover! And there's clearly structure in today's image that doesn't exist in the genuinely high resolution Hubble image. (And note that the HST star sizes are consistent with the detail in the fine structure.)
_
bubble_leader.jpg
bubble_clp.jpg
bubble_hst.jpg

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by tao » Wed Oct 30, 2024 12:56 pm

A bit of a threadjack (or maybe not?):
Today's image of NGC 7635 instantly brought to mind this character:
Image Image

Re: APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by Ann » Wed Oct 30, 2024 7:46 am

David Malin once wrote that bubble structures are much less common in the Milky Way than in many smaller galaxies, "because the interstellar material is at the same time both more constrained and more turbulent in our Galaxy, and these delicate structures are swept away before they become recognisable."

So the Milky Way doesn't have the bubbles of dwarf galaxy NGC 6822:


Ah, but we do have a bubble nebula - the Bubble Nebula!


I like Dominic Gareau's image a lot, because it brings out the Bubble Nebula very clearly while at the same time showing us its nebular environment.

The Bubble Nebula is quite distant. Its Gaia parallax puts it at almost 10,000 light-years away. The central star, BD+60 2522 or SAO 20575, is a hot high-mass mass-losing star.

The most typical mass-losing stars are, of course, the Wolf-Rayet stars.The way I understand it - warning! Amateur explanation! - is that the Wolf-Rayet stars may actually still be on the main sequence and fusing hydrogen to helium in their cores, but they are so massive and so hot inside that their nuclear engines run in overdrive, and they generate so much energy that that they simply blow their outer layers away.


More common, I think, are the Wolf-Rayet stars that have left the main sequence, and their already extremely hot cores undergo large changes, which can lead to pretty violent outbursts and mass-loss events.

As for BD+60 2522, Simbad describes it as an O6.5 type star, so it's not a Wolf-Rayet star yet, although it probably will become one. If you are wondering how Simbad can know that BD+60 2522 is not a Wolf-Rayet star, it's because Wolf-Rayet stars have typical WR lines in their spectra, and BD+60 2522 lacks these. Well, a very hot O-type star can have an outburst anyway.

Actually, my guess is that BD+60 2522 has undergone something that is not so much a mass-loss event as an "eruptive event", where the star "sneezed" or "hiccuped" violently and pushed gas away from it in all directions. Or maybe it suffered from temporary indigestion and releasad a sudden gust of wind? Or maybe the star has just systematically, slowly blown almost all surrounding gas away from it, until the gas that was blown away from the star met the surrounding interstellar medium, forming a bubble-like interface.

And bubbles, or rings, appear in unexpected places.


Ann

APOD: NGC 7635: The Bubble Nebula (2024 Oct 30)

by APOD Robot » Wed Oct 30, 2024 4:06 am

Image NGC 7635: The Bubble Nebula

Explanation: What created this huge space bubble? Blown by the wind from a star, this tantalizing, head-like apparition is cataloged as NGC 7635, but known simply as the Bubble Nebula. The featured striking view utilizes a long exposure to reveal the intricate details of this cosmic bubble and its environment. Although it looks delicate, the 10 light-year diameter bubble offers evidence of violent processes at work. Seen here above and right of the Bubble's center, a bright hot star is embedded in the nebula's reflecting dust. A fierce stellar wind and intense radiation from the star, which likely has a mass 10 to 20 times that of the Sun, has blasted out the structure of glowing gas against denser material in a surrounding molecular cloud. The intriguing Bubble Nebula lies a mere 11,000 light-years away toward the boastful constellation Cassiopeia.

<< Previous APOD This Day in APOD Next APOD >>

Top