Galaxies in the Universe

An image from the Hubble Space Telescope showing hundreds of faraway galaxies. (Image credit: NASA, ESA, CSA, STScI, J. Diego (Instituto de Física de Cantabria, Spain), J. D’Silva (U. Western Australia), A. Koekemoer (STScI), J. Summers & R. Windhorst (ASU), and H. Yan (U. Missouri))



The Milky Way is just a speck in a universe filled with an untold number of galaxies. But if we had to take an educated guess, how many galaxies are in the universe?


That sounds like a simple question, but it's anything but. The first problem is that even with our most powerful telescopes, we can see only a tiny fraction of the universe.


"The observable universe is only that part of the universe from which the light has had time to reach us," astrophysicist Kai Noeske, now outreach officer at the European Space Agency, told Live Science.     
READ MORE...   

Space Telescope Finds Supernova

ASTRONOMERS spotted something unusual happening in a distant galaxy in recent images from the James Webb Space Telescope — something that wasn’t there when Hubble last looked at the same galaxy.

"We suspect it's a supernova," astronomer Mike Engesser of the Space Telescope Science Institute (STScI) tells Inverse. Finding short-lived cosmic events like supernovae isn’t what Webb was designed to do, but the newly-operational space telescope seems to be full of surprises. 

And this one could open the door for looking for the death throes of the universe's first generations of massive stars.  WHAT’S NEW – Engesser and his colleagues say the bright object is probably the first supernova spotted by the Webb Telescope. 

It's extremely bright compared to the rest of the galaxy, for one thing. And Webb observed the galaxy, called SDSS.J141930.11+5251593, twice, five days apart; the object dimmed, just slightly, over those five days — classic supernova behavior.

"We would need more time series data to make a determination, but the data we do have does match that of a supernova, so it's a very good candidate," says Engesser.  READ MORE...