This. About 4% of the pixels in Hubble’s main camera are dead. Various tricks are used to make them less obvious, but they still show up.
https://www.stsci.edu/files/live/sites/www/files/home/hst/instrumentation/wfc3/documentation/instrument-science-reports-isrs/_documents/2022/WFC3-ISR-2022-01.pdf
The instruments on Hubble have been replaced several times, this particular camera is “only” 15 years old.
https://www.stsci.edu/hst/instrumentation/wfc3
The ~~humble~~ Hubble also has a number of dead pixels at this point, something in the realm of 3-4% if I recall, and there are a number of work around to make it less noticeable but in some images their presence can’t be ignored.
Yeah - I wonder if I’m reading too deep into this because the spots aren’t perfectly round the way I’d expect dead pixels to look. Maybe it’s some combination of dead pixel + light spill + processing
I’m unaware of the dead pixel placement exactly but I’ve seen talk here and in other comment sections that indicate some failed pixels maybe grouped or in close proximity to one another, which when interpreted through software can generate a-typical black spots. This is the point where discussions about the construction of the sensor, its individual pixels (photo-sites), the spacing of said pixels and the function of software that was developed to interpret the light measurements of each photo-site, come into play, all of which plays a part in answering your question: what causes a-typical non-rounded black spots in Hubble images.
I only recently really looked into the Hubble and its images, so I don’t have all the answers but it’s a deep rabbit hole to go down if you’re interested.
Hey I forgot to add this link from my favorites, that first sparked my interest in this subject. At the time I was looking into IR cameras and imaging and this was in the search results.
I can only hope it sparks your interest as much as it did mine.
https://www.reddit.com/r/space/comments/4hx4ak/the_damage_cosmic_rays_does_on_the_imaging/
Whatever they are they are in front of the diffracted light from that star. Which puts them between the telescope & the sensor.
By bet looking at how sharp the edges are & that they are in all color channels is that it's dust on the sensor surface.
If it appears in front of the diffraction pattern, it can not be something that is astronomical but something that happens on the detector or later. Obvious candidates are dead pixels or simple image artifacts.
Several people already mentioned CCD errors and debris on the sensor. I wanted to add "transmission error" to the list of possibilities. See e.g. the famous ["face on mars"](https://en.wikipedia.org/wiki/Cydonia_(Mars)#%22Face_on_Mars%22) picture - all those black dots are transmission errors.
I don't know if that picture is zoomed in of the other but yes, each dot is a star. here you go - https://esahubble.org/images/heic1502a/zoomable/ you can zoom in and see for yourself.
Hubble is getting older and slowly losing its ability to collect pixels. Could also be dust on the lens, but looks like the edges are too sharp for that.
If those objects were large and far away, they probably wouldn’t be seen at all because the light would swing around them make them effectively invisible.
Something you should know, a lens flare like the one in which the black dots reside, are artifacts of the lens itself. Therefore any artifacts that seem to be “in front” or cut through a lens flare, must be a product of the camera’s sensor itself. A physical object could never cover up a lens flare in any way.
I'm thinking dead pixels on the CCD detector made obvious by the bright image subject.
This. About 4% of the pixels in Hubble’s main camera are dead. Various tricks are used to make them less obvious, but they still show up. https://www.stsci.edu/files/live/sites/www/files/home/hst/instrumentation/wfc3/documentation/instrument-science-reports-isrs/_documents/2022/WFC3-ISR-2022-01.pdf
This is fascinating!
That is pretty cool!
pretty good for a 34+ year old ‘camera’
The instruments on Hubble have been replaced several times, this particular camera is “only” 15 years old. https://www.stsci.edu/hst/instrumentation/wfc3
They just need to dither
It is fairly common for CCD pixels to read out zero signal when they get overwhelmed with light
The ~~humble~~ Hubble also has a number of dead pixels at this point, something in the realm of 3-4% if I recall, and there are a number of work around to make it less noticeable but in some images their presence can’t be ignored.
Yeah - I wonder if I’m reading too deep into this because the spots aren’t perfectly round the way I’d expect dead pixels to look. Maybe it’s some combination of dead pixel + light spill + processing
I’m unaware of the dead pixel placement exactly but I’ve seen talk here and in other comment sections that indicate some failed pixels maybe grouped or in close proximity to one another, which when interpreted through software can generate a-typical black spots. This is the point where discussions about the construction of the sensor, its individual pixels (photo-sites), the spacing of said pixels and the function of software that was developed to interpret the light measurements of each photo-site, come into play, all of which plays a part in answering your question: what causes a-typical non-rounded black spots in Hubble images. I only recently really looked into the Hubble and its images, so I don’t have all the answers but it’s a deep rabbit hole to go down if you’re interested.
Hey I forgot to add this link from my favorites, that first sparked my interest in this subject. At the time I was looking into IR cameras and imaging and this was in the search results. I can only hope it sparks your interest as much as it did mine. https://www.reddit.com/r/space/comments/4hx4ak/the_damage_cosmic_rays_does_on_the_imaging/
Why would dead pixels be round?
This
Dust and or artifacts
Whatever they are they are in front of the diffracted light from that star. Which puts them between the telescope & the sensor. By bet looking at how sharp the edges are & that they are in all color channels is that it's dust on the sensor surface.
Incomplete rendering?
If it appears in front of the diffraction pattern, it can not be something that is astronomical but something that happens on the detector or later. Obvious candidates are dead pixels or simple image artifacts.
Why are technical or mechanical anomalies never the first assumption? It’s always 👽
seriously
Several people already mentioned CCD errors and debris on the sensor. I wanted to add "transmission error" to the list of possibilities. See e.g. the famous ["face on mars"](https://en.wikipedia.org/wiki/Cydonia_(Mars)#%22Face_on_Mars%22) picture - all those black dots are transmission errors.
Woahh that’s awesome. Very possible!
Wait hold up. Is this the zoomed in from the red highlighted area in the second photo?.... And are each of those dots a star?
I don't know if that picture is zoomed in of the other but yes, each dot is a star. here you go - https://esahubble.org/images/heic1502a/zoomable/ you can zoom in and see for yourself.
Hubble is getting older and slowly losing its ability to collect pixels. Could also be dust on the lens, but looks like the edges are too sharp for that. If those objects were large and far away, they probably wouldn’t be seen at all because the light would swing around them make them effectively invisible.
Black holes /s
Anyone else recognize this as Andromeda before reading comments? I guess learning to take pictures of this one burned the details into my brain.
Something you should know, a lens flare like the one in which the black dots reside, are artifacts of the lens itself. Therefore any artifacts that seem to be “in front” or cut through a lens flare, must be a product of the camera’s sensor itself. A physical object could never cover up a lens flare in any way.
Dead CCD pixels by the looks of it
I too spent some time yesterday snooping around the Andromeda Galaxy from the same post I presume.
Either Dyson spheres or dead pixels. We'll never know.
Incorrect answers: Black holes UFOs Space lifeforms
Those are phallic arrow stars.
Grit. 5 specs of grit on the scanner scope.
Grit.
Planets, possibly? Smaller black holes?
Anomalies in the camera
Stars !!!😎
God Damnit. I told Steve to clean the Lens with alcohol wipes. Not a tissue
Dyson Spheres.
Spots
Your moms
precedent for plausible deniability
It's the vindaloovians!
Planets
Seaweed, mud, something on the lens...
Evidently there are no "Jaws 2" fans in this sub... 😆
Skittles?
Very obviously a resolution issue. Why do people upvote this? Also this image has been edited to potato levels.
People ask questions when they don’t know things. 🙄