Hubble peered through dust and gas to capture this dazzling globular cluster

By Georgina Torbet September 26, 2021

This week’s image from the beloved Hubble Space Telescope shows a dazzling array of stars, squeezed into a group known as a globular cluster. This is a dense collection of stars held together by gravity, forming a roughly spherical shape and composed of hundreds of thousands or even millions of stars.

This particular cluster is named ESO 520-21 and is also known as Palomar 6 after the Palomar Observatory in California where it was discovered in a sky survey in the 1980s.

This sparkling starfield, captured by the NASA/ESA Hubble Space Telescope’s Wide Field Camera 3 and Advanced Camera for Surveys, contains the globular cluster ESO 520-21 (also known as Palomar 6). — This sparkling starfield, captured by the NASA/ESA Hubble Space Telescope’s Wide Field Camera 3 and Advanced Camera for Surveys, contains the globular cluster ESO 520-21 (also known as Palomar 6). ESA/Hubble and NASA, R. Cohen

Capturing this image wasn’t easy because the cluster is located near the center of our galaxy. There is a lot of matter floating around in the central region of the galaxy, making it hard to capture a clear image.

“A densely packed, roughly spherical collection of stars, it lies close to the center of the Milky Way, where interstellar gas and dust absorb starlight and make observations more challenging,” Hubble scientists write.

“Interstellar absorption affects some wavelengths of light more than others, changing the colors of astronomical objects by causing them to appear redder than they actually are. Astronomers call this process ‘reddening,’ and it makes determining the properties of globular clusters close to the galactic center — such as ESO 520-21 — particularly difficult.”

This difficulty means there are many questions about this cluster that are hard to answer. Researchers weren’t sure of the cluster’s age, or exactly how far away from us it is. They also weren’t sure what heavier elements exist there in what quantities.

But recently, astronomers from the University of São Paulo in Brazil have studied this cluster using both Hubble and the Very Large Telescope and found that it is 12.4 billion years old and is located 25,000 light-years away.

Editors' Recommendations

Topics

Georgina Torbet

Space Writer

Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…

Space

Hubble captures a messy irregular galaxy which hosted a supernova

The irregular spiral galaxy NGC 5486 hangs against a background of dim, distant galaxies in this image from the NASA/ESA Hubble Space Telescope. The tenuous disk of the galaxy is threaded through with pink wisps of star formation, which stand out from the diffuse glow of the galaxy’s bright core.

This week's image from the Hubble Space Telescope shows a dramatic spiral galaxy called NGC 5486, which is shot through with wisps of pink showing regions where new stars are being born.

Located 110 million light-years away in the famous constellation of Ursa Major, this galaxy is a type called an irregular spiral galaxy because its arms are wandering and indistinct. If you compare the image of this galaxy to one of a quintessential spiral galaxy like NGC 2336, you'll see that a non-irregular spiral galaxy has clearly defined arms that reach out from its center and are symmetrical.

Space

Hubble captures a cosmic sea monster with this image of a jellyfish galaxy

A jellyfish galaxy with trailing tentacles of stars hangs in inky blackness in this image from the NASA/ESA Hubble Space Telescope. As Jellyfish galaxies move through intergalactic space they are slowly stripped of gas, which trails behind the galaxy in tendrils illuminated by clumps of star formation. These blue tendrils are visible drifting below the core of this galaxy, and give it its jellyfish-like appearance. This particular jellyfish galaxy — known as JO201 — lies in the constellation Cetus, which is named after a sea monster from ancient Greek mythology. This sea-monster-themed constellation adds to the nautical theme of this image.

This week's image from the Hubble Space Telescope shows a special and delightful cosmic object: a jellyfish galaxy. These galaxies are named for their larger main body with tendrils that float along after them, like the sea creatures.

This particular jellyfish galaxy is called JO201, and is located in the constellation of Cetus. Appropriately for the sea theme, Cetus is a constellation named after a Greek mythological sea monster that sometimes had the body of a whale or serpent along with the head of a boar. In the image, you can see the main body of the galaxy in the center, with the trailing tendrils spreading down toward the bottom of the frame.

Space

Satellites like SpaceX’s Starlink are disrupting Hubble observations

The curving light streak created by an artificial satellite mars an image taken by the Hubble Space Telescope.

Astronomers are once again worried about the effect that satellites like those used by SpaceX for its Starlink service will have on scientific research. A recent study looked at the effect that such satellites were having on observations from the Hubble Space Telescope and found that observations were already being impacted by the number of satellites nearby.

Telescopes like Hubble are particularly vulnerable to interference from satellites because of their location, in an area called low-Earth orbit (LEO). At less than 1,200 miles above the Earth's surface, this region is prime real estate for both scientific projects like Hubble and the International Space Station and for commercial projects like satellite megaconstellations. While there have been satellites in this region for many years, recently the number of satellites has been rising dramatically, especially due to projects like Starlink which rely on having thousands of satellites in orbit.