Interesting Astronomy & Astrophysics news from the week of 12/13/2020

Next week’s night sky:

Tomorrow, one of the most interesting and rare astronomy events happens! Jupiter and Saturn will be closer together than they ever have been since 1683. This event will not happen again until 2080!. Tomorrow, look towards the southwestern sky just after sunset. You should see a huge dot, brighter than any star in the sky. It should even be visible through clouds to the naked eye! With binoculars, you should be able to see the individual planets, Jupiter being the larger one. 

The Shadows of a Black Hole

NASA’s Hubble Space Telescope recently captured this sunset-esque view of the nearby galaxy IC 5063, located some 156 million light-years from Earth. Beams of light — along with their shadowy counterparts — seem to streak out from the center of this galaxy, just as sunlight creates similar shadows and beams of light during a cloudy sunset here on Earth. 

A team of researchers traced the rays and resulting shadows back to a supermassive black hole at the center of IC 5063. Because the black hole is gobbling up nearby material at a rapid rate, its food piles up around it like too much water going down a small drain. This cosmic whirlpool causes the circling material to heat up and glow around the otherwise black hole. 

The light then hits dense patches in the dust ring, which casts shadows out into space. And thanks to the orientation of the black hole compared to its galaxy, the beams of light and the shadows are visible to us here on Earth. 

To learn more, go here: The Astrophysical Journal Letters – IOPscience.

The Farthest Galaxy

A team of astronomers used the Keck I telescope to measure the distance to an ancient galaxy. They deduced the target galaxy GN-z11 is not only the oldest galaxy but also the most distant. It’s so distant it defines the very boundary of the observable universe itself. The team hopes this study can shed light on a period of cosmological history when the universe was only a few hundred million years old.

From previous studies, the galaxy GN-z11 seems to be the farthest detectable galaxy from us, at 13.4 billion light-years, or 134 nonillion kilometers (that’s 134 followed by 30 zeros). But actually measuring the distance is not so easy.

They used the MOSFIRE telescope to capture the emission lines from GN-z11 in detail, which allowed the team to make a much better estimation of its distance than was possible from previous data. When working with distances at these scales, it is not sensible to use our familiar units of kilometers or even multiples of them; instead, astronomers use a value known as the redshift number denoted by z. Kashikawa and his team improved the accuracy of the galaxy’s z value by a factor of 100. If subsequent observations can confirm this, then the astronomers can confidently say GN-z11 is the farthest galaxy ever detected in the universe. 

To learn more, go here: Evidence for GN-z11 as a luminous galaxy at redshift 10.957.

Do you have any cool astronomy research news from this week? Share it in the comments below!