There’s something very strange about this image from the Hubble Space Telescope. If you look closely, it looks like almost two mirror images, two orange galaxies, connected by a long thread.

Surprisingly, it is not two galaxies, but one, and its name is SGAS J143845 + 145407. Thanks to the gravitational pull of a massive object (or group of galaxies), it seems that there are only two. Faraway is where light travels.

Imagine putting a heavy weight on a trampoline, where the weight represents the mass of galaxies and the trampoline mat represents spacetime. Now roll some balls from one side of the trampoline to the other. Its normal “straight” paths appear bent in different paths, not like rays of light through distorted space.

This gravitational variation, known as gravitational lensing, is used to magnify the light of background galaxies that are too far away to see in great detail, as shown in the diagram below.

Gravitational lens diagram. (NASA, European Space Agency and El Calcutta)

Gravitational lenses like these can therefore be an important tool for understanding the distant universe.

Sometimes this light is distorted and distorted, as seen in a recent deep-field image from the James Webb Space Telescope. Those wobbly, worm-like strange objects are lenticular galaxies. When the lens effect produces four images of a distant object lined up around the central lens block, it is called an Einstein cross.

SGAS J143845 + 145407 appears at the right point behind the gravitational lensing of a small galaxy cluster, producing two close-up perfect images of the galaxy.

Light from SGAS J143845 + 145407 has traveled about 6.9 billion years to reach us. This is half the lifetime of the current universe. The cluster’s light traveled about 2.8 billion years.

Mirror images of SGAS J143845 + 145407 around a gravitational lens. (ESA/Hubble and NASA, J. Rigby)

SGAS J143845 + 145407 is scientifically interesting because it is an infrared-luminous galaxy that glows relatively brightly due to high star formation activity. Studying galaxies like hers will help scientists understand star formation and how it has changed throughout the history of the universe. For this type of work, gravity lenses can be invaluable.

Using gravitational lensing, scientists have recently been able to do this Reconstruction of the star formation distribution in SGAS J143845 + 145407And read the details of the process. They found that a galaxy is mostly of its kind, meaning information that helps to contextualize and classify other galaxies.

Webb is expected to reveal more details, but Hubble has revolutionized the study of lenticular galaxies. His observations were the first to resolve details within lenticular galaxies, giving scientists a new window into the early universe.

The photo was published that day Hubble site.