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In the first image released by the James Webb Space Telescope, some galaxies seem to have many bright dots - what are these? Young, huge stars? Supernovae? Just hot things behind the galaxy?

enter image description here

enter image description here

(30 MB full resolution here)

Saurav Maheshkar
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  • Regarding the bottom image: I too quickly gravitated to that when the pic was published. It appears to be a jet spurting from a quasar. Or just a coincidental positioning of different entities. – White Prime Jul 12 '22 at 10:20
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    I doubt the dots are stars, I would suggest perhaps clusters but haven't got anything to prove that. I doubt its a jet, note that it has a central bright region (note the diffraction spikes) so its probably just a coincidental alignment with another galaxy, and the rbight spot is the center of that Galaxy.. – Rob Jul 12 '22 at 11:44
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    It's the diffraction pattern that you usually only see from bright stars, but JWST is so sensitive and has so high resolution that the nuclei of some bright and compact galaxies show it as well. It will probably be a bit of a problem removing them. – pela Jul 12 '22 at 12:11
  • @pela It doesn't look like the diffraction pattern to me. There are many other places in the image where the diffraction pattern is evident and they don't show these seemingly-randomly scattered dots around the source. They look like something physical to me – Prallax Jul 13 '22 at 20:46
  • @Prallax: it does roughly seem like the diffraction pattern to me. It has the same number of spikes (6) as a star, the spikes are just fuzzier and less defined. Maybe the light from some galaxies is simply point-like enough that we start to see that spike pattern. It was something I thought was curious as well. – Greg Burghardt Jul 14 '22 at 01:38
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    @Prallax Ah, sorry, I misunderstood! No, those things are probably globular (star) clusters, belonging to the galaxy. It's quite amazing that they're resolved :) – pela Jul 14 '22 at 08:31
  • (btw, I don't think a quantum mechanic would like to hear that diffraction is not physical ;-) ) – pela Jul 14 '22 at 08:35
  • @pela ops! I hope no quantum mechanic/optic expert passes by and gets personally offended ;) – Prallax Jul 14 '22 at 11:31
  • @pela I think your comments would make combined for a brief yet nice answer. – planetmaker Jul 14 '22 at 11:33
  • @planetmaker maybe it's better to wait some time. My impression is that it is too soon to tell with certainty, but I bet that in a few days/weeks many people will have analyzed the data and will have come out with more solid conclusions – Prallax Jul 14 '22 at 11:38
  • @Prallax Yes, I'm not certain enough to write an answer at this point. But I just discussed with a colleague that agrees. – pela Jul 14 '22 at 11:46
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    @pela great! Keep us updated! – Prallax Jul 14 '22 at 11:58

1 Answers1

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Myung Gyoon Lee et al 2022 seem confident that they are globular clusters.

Faisst et al 2022 seem to also consider the possibility that they could be stripped cores of dwarf galaxies.

They are both analyzing small dots near a galaxy in the SMACS field, but is different from the one in the OP. I am not sure these findings can also be applied to the picture in the OP.

Prallax
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