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What is this structure in the Hubble WFC3 814W and 606W capture of NGC 5189 ?

Planetary Nebula
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Pranay Kanwar avatar
Pranay Kanwar avatar
There is a strange infinity/dumbbell shaped structure like the one below.


Full image, a stretch of 814W capture.



You can also see them just at the bottom, two similar faint structures. The same is seen in F606W at the exact location, though very faint.

Filter details
https://hst-docs.stsci.edu/acsihb/chapter-10-imaging-reference-material/10-3-throughputs-and-correction-tables/wfc-f814w
https://hst-docs.stsci.edu/acsihb/chapter-10-imaging-reference-material/10-3-throughputs-and-correction-tables/wfc-f606w

It makes sense it is seen in both 814W/606W as there is a slight overlap in response to wavelengths in these filters. From proposal id 12812 https://archive.stsci.edu/proposal_search.php?mission=hst&id=12812

Plan is too look for similar structures, around planetary nebulas if it is not something instrument/optical related.
andrea tasselli avatar
andrea tasselli avatar
Optical gremlins, even the HST isn't free of them…
Peter Myers avatar
Peter Myers avatar
Eyes of God…playing Kilroy was here   smile
Joe Linington avatar
Joe Linington avatar
You have to find it in an overlapping image to confirm or overlay the 2 images and see if there is enough movement of the field to confirm it isn't an aberration.
Pranay Kanwar avatar
Pranay Kanwar avatar
andrea tasselli:
Optical gremlins, even the HST isn't free of them...

Yes, that was my first guess also .  I reached out to Mehmeton Instagram, who confirmed they see it all the time and pointed me to this resource https://illuminateduniverse.org/2021/04/01/image-artifacts/. See the  "Donuts, Ghosts, and Glints" section.
Pranay Kanwar avatar
Pranay Kanwar avatar
Joe Linington:
You have to find it in an overlapping image to confirm or overlay the 2 images and see if there is enough movement of the field to confirm it isn't an aberration.


I didn't understand the entire thing. Maybe an example, if possible?
John Bozeman avatar
John Bozeman avatar
Optics artifact. Very common in HST WFC3 and ACS data. Use clone stamp and spot healing brush to remove.
Michael Gruenwald avatar
Michael Gruenwald avatar
Talking about weirds….
Posted this on Cloudy Nights a few months back and didn’t get a real response
Imaging SH2-157, the Lobster Claw nebula I found this little guy in the unprocessed SHO preview ( some 17 hours integration so far, 3nm narrowband) What's up with these apparent "rays", most apparent in Ha? don't think I have ever seen anything like it, I don't think its an artifact, shows up un several images on the web...


 A Herbig Ae/Be Star at the green arrow, but i am interested in the tiny guy next to it, with the peculiar “radiating pattern“… thanks,Mike
Michael Gruenwald avatar
Michael Gruenwald avatar
andrea tasselli avatar
andrea tasselli avatar
Maybe a higher resolution image would give better data. What it is its redshift?
Michael Gruenwald avatar
Michael Gruenwald avatar
andrea tasselli:
Maybe a higher resolution image would give better data. What it is its redshift?

If you klick the image on Astrobin (linked above) you’ll get the native resolution.

redshift? Don’t think I can estimate that for a stellar object with data from my backyard rig😀
Thomas W avatar
Thomas W avatar
Looks like ghost reflections of a bright star from two optical surfaces. You can see a second one in the F814W image if you brighten it. Bit of digging shows that they're well aware of this, see section 6.5.3: https://hst-docs.stsci.edu/wfc3ihb/chapter-6-uvis-imaging-with-wfc3/6-5-uvis-spectral-elements#id-6.5UVISSpectralElements-6.5.3
Helpful Insightful Concise
andrea tasselli avatar
andrea tasselli avatar
Michael Gruenwald:
If you klick the image on Astrobin (linked above) you’ll get the native resolution.

redshift? Don’t think I can estimate that for a stellar object with data from my backyard rig😀


I mean actual higher resolution, not bigger picture. And as for the redshift and other info you might get I suggest you research around the object's location with tools such as Aladin, Simbad and such.
Pranay Kanwar avatar
Pranay Kanwar avatar
Looks like ghost reflections of a bright star from two optical surfaces. You can see a second one in the F814W image if you brighten it. Bit of digging shows that they're well aware of this, see section 6.5.3: https://hst-docs.stsci.edu/wfc3ihb/chapter-6-uvis-imaging-with-wfc3/6-5-uvis-spectral-elements#id-6.5UVISSpectralElements-6.5.3


Thanks, this was very informative.