Portrait of a galaxy cluster

A massive, spacetime-warping cluster of galaxies, Abell 209, is the setting of today’s NASA/ESA Hubble Space Telescope Picture of the Week.

Credit: ESA/Hubble & NASA, M. Postman, P. Kelly
https://esahubble.org/images/potw2527a/

Incredible new #JWST deep field (120 hours!) released by folks from ESA/NASA Webb teams.

Not only is nearly everything in this image a galaxy (the two spiky stars are not), but those curved arcs are images of galaxies beyond this cluster, which are projected and warped into our view thanks to the power of gravity!

It's called a gravitational lens. To visualise what's happening, take a look at this diagram.

There are distant galaxies that we can't normally see. There's also a galaxies between them and us, with lots of mass.

This mass warps space-time and bends the distant galaxy light towards us so we see them.

I am amazed. You should be amazed. This is a really epic image.

Galaxy image and alt-text credit: ESA/Webb, NASA & CSA, H. Atek, M. Zamani (ESA/Webb)

Diagram credit: NASA, ESA & L. Calçada

The JWST Discovery of the Triply-imaged Type Ia "Supernova H0pe" and Observations of the #GalaxyCluster PLCK G165.7+67.0: https://arxiv.org/abs/2309.07326 -> JWST’s first triple-image supernova could save the Universe: https://bigthink.com/starts-with-a-bang/triple-lens-supernova-jwst/ - named #Supernova H0pe, it shows how #JWST plus #GravitationalLensing can be used to solve the greatest puzzle facing astronomy today, the #HubbleConstant tension.

#GravitationalLensing by the #GalaxyCluster SDSS J1226+2149, imaged by the #JWST's NIRCAM from 1.2 bis 4.4 µm (particularly funny details): https://esawebb.org/images/potm2303a/

Two views of the galaxy cluster #SMACS0723—#HubbleSpaceTelescope on the left, #JamesWebbSpaceTelescope on the right. #Hubble’s image on the left shows many faint stars and galaxies, but the #Webb image absolutely pops with light, revealing many hidden structures.

Hubble vs Webb: https://webb.nasa.gov/content/about/comparisonWebbVsHubble.html