Skip to main content

Stars sparkle in various colors in this week’s Hubble image

Close out your week with a soothing view of the wonders of space, as provided by the Hubble Space Telescope. This week’s image from Hubble shows an enormous structure of stars called a globular cluster, located 23,000 light-years away in the constellation of Sagittarius.

A globular cluster is a group of thousands or even millions of stars that are held together by gravity. This group, named NGC 6558, is located close to the center of the Milky Way. Previous Hubble images also show similar globular clusters near the heart of our galaxy, which are being investigated as part of a Hubble project.

This glittering gathering of stars is the globular cluster NGC 6558, and it was captured by the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys. NGC 6558 is closer to the center of the Milky Way than Earth is, and lies about 23,000 light-years away in the constellation Sagittarius.
This glittering gathering of stars is the globular cluster NGC 6558, and it was captured by the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys. NGC 6558 is closer to the center of the Milky Way than Earth is, and lies about 23,000 light-years away in the constellation Sagittarius. Image used with permission by copyright holder

“Globular clusters are interesting natural laboratories where astronomers can test their theories,” Hubble scientists write. “Because the stars in a globular cluster formed at approximately the same time with similar initial compositions, they provide unique insights into how different stars evolve under similar conditions. This image comes from a set of observations investigating globular clusters in the inner Milky Way. Astronomers were interested in studying these globular clusters to gain greater insight into how they form and evolve.”

As you can see in the image, stars come in a variety of colors, and this color can gives clues to their age. That’s because a star’s color is a function of how hot its surface is, and surface temperature is related to age. However, the mass of a star also plays a role, not to mention factors like the redshift observed in very distant stars or dust which can get in the way and affect the perceived color of a star. Generally speaking, blue stars are typically the youngest and hottest, while as stars age and use up their fuel they become cooler and redder.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Hubble spies baby stars being born amid chaos of interacting galaxies
Galaxy AM 1054-325 has been distorted into an S-shape from a normal pancake-like spiral shape by the gravitational pull of a neighboring galaxy, seen in this Hubble Space Telescope image. A consequence of this is that newborn clusters of stars form along a stretched-out tidal tail for thousands of light-years, resembling a string of pearls. They form when knots of gas gravitationally collapse to create about 1 million newborn stars per cluster.

When two galaxies collide, the results can be destructive, with one of the galaxies ending up ripped apart, but it can also be constructive too. In the swirling masses of gas and dust pulled around by the gravitational forces of interacting galaxies, there can be bursts of star formation, creating new generations of stars. The Hubble Space Telescope recently captured one such hotbed of star formation in galaxy AM 1054-325, which has been distorted into an unusual shape due to the gravitational tugging of a nearby galaxy.

Galaxy AM 1054-325 has been distorted into an S-shape from a normal pancake-like spiral shape by the gravitational pull of a neighboring galaxy, as seen in this Hubble Space Telescope image. A consequence of this is that newborn clusters of stars form along a stretched-out tidal tail for thousands of light-years, resembling a string of pearls. NASA, ESA, STScI, Jayanne English (University of Manitoba)

Read more
Small exoplanet could be hot and steamy according to Hubble
This is an artist’s conception of the exoplanet GJ 9827d, the smallest exoplanet where water vapour has been detected in its atmosphere. The planet could be an example of potential planets with water-rich atmospheres elsewhere in our galaxy. It is a rocky world, only about twice Earth’s diameter. It orbits the red dwarf star GJ 9827. Two inner planets in the system are on the left. The background stars are plotted as they would be seen to the unaided eye looking back toward our Sun, which itself is too faint to be seen. The blue star at upper right is Regulus, the yellow star at bottom centre is Denebola, and the blue star at bottom right is Spica. The constellation Leo is on the left, and Virgo is on the right. Both constellations are distorted from our Earth-bound view from 97 light-years away.

One of the big topics in exoplanet research right now is not just finding exoplanets but also looking at their atmospheres. Tools like the James Webb Space Telescope are designed to allow researchers to look at the light coming from distant stars and see how it is filtered as it passes by exoplanets, allowing them to learn about the composition of their atmospheres. But scientists are also using older telescopes like the Hubble Space Telescope for similar research -- and Hubble recently identified water vapor in an exoplanet atmosphere.

“This would be the first time that we can directly show through an atmospheric detection that these planets with water-rich atmospheres can actually exist around other stars,” said researcher Björn Benneke of the Université de Montréal in a statement. “This is an important step toward determining the prevalence and diversity of atmospheres on rocky planets."

Read more
Hear the otherworldly sounds of interacting galaxies with this Hubble sonification
This new NASA Hubble Space Telescope image showcases a resplendent pair of galaxies known as Arp 140.

When two different galaxies get close enough together that they begin interacting, they are sometimes given a shared name. That's the case with a newly released image from the Hubble Space Telescope that shows two galaxies, NGC 274 and NGC 275, which are together known as Arp 140. not only is there a new image of the pair, but there's also a sonification available so you can hear the image as well as see it.

This new NASA Hubble Space Telescope image showcases a resplendent pair of galaxies known as Arp 140. NASA/ESA/R. Foley (University of California - Santa Cruz)/Processing: Gladys Kober (NASA/Catholic University of America)

Read more