Skip to main content

Thousands of stars press close together in stunning Hubble image

If this week’s release of the biggest James Webb image so far hasn’t fully satisfied your urge for beautiful pictures of space, the old faithful Hubble Space Telescope is here for you. Each week, Hubble researchers share an image collected by the 30-year-old telescope, and this week shows a dazzling globular cluster by the name of NCG 6540.

A globular cluster is a group of tens of thousands or even millions of stars, which are packed closely together and held in a cluster by their shared gravity. This particular globular cluster was imaged using two of Hubble’s instruments, the Wide Field Camera 3 and the Advanced Camera for Surveys.

Related Videos
This scintillating image showcases the globular cluster NGC 6540 in the constellation Sagittarius, which was captured by the NASA/ESA Hubble Space Telescope’s Wide Field Camera 3 and Advanced Camera for Surveys. These two instruments have slightly different fields of view — which determines how large an area of sky each instrument captures. This composite image shows the star-studded area of sky that was captured in both instruments’ field of view.
This scintillating image showcases the globular cluster NGC 6540 in the constellation Sagittarius, which was captured by the NASA/ESA Hubble Space Telescope’s Wide Field Camera 3 and Advanced Camera for Surveys. These two instruments have slightly different fields of view — which determines how large an area of the sky each instrument captures. This composite image shows the star-studded area of the sky that was captured in both instruments’ fields of view. ESA/Hubble & NASA, R. Cohen

This cluster is located around 17,000 light years away and is in the constellation of Sagittarius. It was first observed in 1784 by William Herschel, who originally classified it as a “faint nebula,” but its true nature as a globular cluster was noted when it was observed by Celtech astronomer Stanislav George Djorgovski in 1986.

Studying these huge groups of stars can help astronomers learn more about the evolution of stars and galaxies, and this image was collected as part of a study into globular clusters within the Milky Way. As Hubble scientists explain, “Hubble peered into the heart of NGC 6540 to help astronomers measure the ages, shapes, and structures of globular clusters towards the center of the Milky Way. The gas and dust shrouding the center of our galaxy block some of the light from these clusters, as well as subtly changing the colors of their stars … Globular clusters contain insights into the earliest history of the Milky Way, and so studying them can help astronomers understand how our galaxy has evolved.”

Editors' Recommendations

Hubble sees the dramatic collision of NASA’s DART spacecraft and an asteroid
These three panels capture the breakup of the asteroid Dimorphos when it was deliberately hit by NASA's 1,200-pound Double Asteroid Redirection Test (DART) mission spacecraft on September 26, 2022. Hubble Space Telescope had a ringside view of the space demolition derby.

Last year NASA tested out a new method for defending the planet from incoming objects by crashing a spacecraft into an asteroid. Recently, further analysis of data from the impact has shown more about what occurred during and after the impact, and how effective it was at changing the orbit of the asteroid.

The Hubble Space Telescope captured a series of images showing the aftermath of the impact, which have been put together into a video showing the bright flash of the impact and the emerging plume of material sent up from the asteroid:

Read more
An enormous galaxy cluster warps spacetime in this Hubble image
A massive galaxy cluster in the constellation Cetus dominates the centre of this image from the NASA/ESA Hubble Space Telescope. This image is populated with a serene collection of elliptical and spiral galaxies, but galaxies surrounding the central cluster — which is named SPT-CL J0019-2026 — appear stretched into bright arcs, as if distorted by a gargantuan magnifying glass. This cosmic contortion is called gravitational lensing, and it occurs when a massive object like a galaxy cluster has a sufficiently powerful gravitational field to distort and magnify the light from background objects.

Every week, scientists using the Hubble Space Telescope share an image from this beloved piece of space technology, and this week's image shows a vital astronomical phenomenon in action. While space telescopes can observe very far-off objects if they are bright enough, there is still a lot of the universe that is too far away to observe -- which is why researchers make use of a natural occurrence called gravitational lensing.

Gravitational lensing happens when an object like a galaxy or galaxy cluster has so much mass that it noticeably warps spacetime. Everything with mass bends spacetime somewhat, but usually this effect is so small as to be effectively invisible. But when the object is something with as much mass as a large galaxy or even a collection of galaxies, then this warping can be significant enough for us to observe it.

Read more
Three galaxies are in the process of merging in this Hubble image
A spectacular trio of merging galaxies in the constellation Boötes takes center stage in this image from the NASA/ESA Hubble Space Telescope. These three galaxies are set on a collision course and will eventually merge into a single larger galaxy, distorting one another’s spiral structure through mutual gravitational interaction in the process. An unrelated foreground galaxy appears to float serenely near this scene, and the smudged shapes of much more distant galaxies are visible in the background.

This week's image from the Hubble Space Telescope shows a dramatic collision of three different galaxies. The trio, located in the Boötes constellation, are in the process of merging and will eventually form one single large galaxy.

A spectacular trio of merging galaxies in the constellation Boötes takes center stage in this image from the NASA/ESA Hubble Space Telescope. These three galaxies are set on a collision course and will eventually merge into a single larger galaxy, distorting one another’s spiral structure through mutual gravitational interaction in the process. An unrelated foreground galaxy appears to float serenely near this scene, and the smudged shapes of much more distant galaxies are visible in the background. ESA/Hubble & NASA, M. Sun

Read more