Skip to main content

James Webb spots another pair of galaxies forming a question mark

MACS J0417.5-1154 Wide Field (NIRCam)
MACS J0417.5-1154 Wide Field (NIRCam) NASA, ESA, CSA, STScI, Vicente Estrada-Carpenter (Saint Mary's University)

The internet had a lot of fun last year when eagle-eyed viewers spotted a galaxy that looked like a question mark in an image from the James Webb Space Telescope. Now, Webb has stumbled across another questioning galaxy, and the reasons for its unusual shape reveal an important fact about how the telescope looks at some of the most distant galaxies ever observed.

The new question mark-shaped galaxy is part of an image of galaxy cluster MACS-J0417.5-1154, which is so massive that it distorts space-time. Extremely massive objects — in this case, a cluster of many galaxies — exert so much gravitational force that they bend space, so the light traveling past these objects is stretched. It’s similar using a magnifying glass. In some cases, this effect, called gravitational lensing, can even make the same galaxy appear multiple times in different places within one image.

The galaxy cluster MACS-J0417.5-1154 is so massive it is warping the fabric of space-time and distorting the appearance of galaxies behind it, an effect known as gravitational lensing. This natural phenomenon magnifies distant galaxies and can also make them appear in an image multiple times, as NASA’s James Webb Space Telescope saw here.
The galaxy cluster MACS-J0417.5-1154 is so massive it is warping the fabric of space-time and distorting the appearance of galaxies behind it via an effect known as gravitational lensing. This natural phenomenon magnifies distant galaxies and can also make them appear in an image multiple times, as NASA’s James Webb Space Telescope shows here. NASA, ESA, CSA, STScI, Vicente Estrada-Carpenter (Saint Mary's University)

This particular case is the result of the Earth, the galaxy cluster, and the target galaxy lining up just so, and it’s called a hyperbolic umbilic gravitational lens. There is actually one pair of galaxies here, but the lensing makes it appear five times and creates the question mark shape.

Recommended Videos

“We know of only three or four occurrences of similar gravitational lens configurations in the observable universe, which makes this find exciting, as it demonstrates the power of Webb and suggests maybe now we will find more of these,” said astronomer Guillaume Desprez of Saint Mary’s University in Halifax, Nova Scotia, in a statement.

The image was taken with Webb’s NIRCam instrument, but the researchers also used Webb’s NIRISS instrument to pick out where star formation was occurring, even in a galaxy located billions of light-years away. The rate of star formation can be ramped up when two galaxies are in the process of merging or colliding.

“Knowing when, where, and how star formation occurs within galaxies is crucial to understanding how galaxies have evolved over the history of the universe,” said astronomer Vicente Estrada-Carpenter of Saint Mary’s University. “Both galaxies in the Question Mark Pair show active star formation in several compact regions, likely a result of gas from the two galaxies colliding. However, neither galaxy’s shape appears too disrupted, so we are probably seeing the beginning of their interaction with each other.”

As well as being a fun oddity, the galaxies seen here are useful models of what our own galaxy was like when it was younger.

“These galaxies, seen billions of years ago when star formation was at its peak, are similar to the mass that the Milky Way galaxy would have been at that time. Webb is allowing us to study what the teenage years of our own galaxy would have been like,” said Marcin Sawicki of Saint Mary’s University.

The research is published in the Monthly Notices of the Royal Astronomical Society.

Georgina Torbet
Georgina has been the space writer at Digital Trends space writer for six years, covering human space exploration, planetary…
Hubble images a pair of tiny dwarf galaxies
hubble dwarf galaxy pair ic3430 potw2431a 1

A new image from the Hubble Space Telescope shows a small dwarf galaxy called IC 3430 that's located 45 million light-years away. This galaxy is classified as both a dwarf galaxy, because of its small size, and an elliptical galaxy, because of its form.

Elliptical galaxies are smooth and featureless, appearing blob-like and diffuse, unlike spiral galaxies, like our Milky Way, which have a distinct structure of a central hub and stretching spiral arms.

Read more
James Webb takes rare direct image of a nearby super-Jupiter
Artist’s impression of a cold gas giant orbiting a red dwarf. Only a point of light is visible on the JWST/MIRI images. Nevertheless, the initial analysis suggests the presence of a gaseous planet that may have properties similar to Jupiter.

Even with huge ground-based observatories and the latest technology in space-based telescopes, it's still relatively rare for astronomers to take an image of an exoplanet. Planets outside our solar system are so far away and so small and dim compared to the stars they orbit that it's extremely difficult to study them directly. That's why most observations of exoplanets are made by studying their host stars. Now, though, the James Webb Space Telescope has directly imaged a gas giant -- and it's one of the coldest exoplanets observed so far.

The planet, named Epsilon Indi Ab, is located 12 light-years away and has an estimated temperature of just 35 degrees Fahrenheit (2 degrees Celsius). The fact it is so cool compared to most exoplanets meant that Webb's sensitive instruments were needed to study it.

Read more
One half of this wild exoplanet reaches temperatures of 1,450 degrees Fahrenheit
webb wasp 39b dayside nightside stsci 01j2f12rm1s3n39yj938nhsf93 png

This artist’s concept shows what the exoplanet WASP-39 b could look like based on indirect transit observations from JWST and other space- and ground-based telescopes. Data collected by its NIRSpec (Near-Infrared Spectrograph) show variations between the morning and evening atmosphere of the planet. NASA, ESA, CSA, Ralf Crawford (STScI)

One of the ground-breaking abilities of the James Webb Space Telescope is that researchers can use it to not only detect distant planets but also to peer into their atmosphere. Now, new research using Webb has uncovered differing conditions between morning and evening on a distant exoplanet, the first time such differences have been observed on a planet outside our solar system.

Read more