Greetings, fellow explorers,
There is something unexpectedly familiar about Arp 107. A bright curve, two glowing patches, and suddenly a pair of distant galaxies seems to be smiling back at us. Once you notice the resemblance, it is difficult to look away.
But spend a little longer with the image. The broken ring and the faint connection between the galaxies tell a story that is still unfolding.
A meeting that reshaped two galaxies
Arp 107 brings together a spiral galaxy and a smaller elliptical companion in the constellation Leo Minor. NASA places the pair roughly 465 million light-years from Earth. Their encounter has disturbed the spiral’s arms, producing the unusual shape that catches our attention.
The smaller galaxy likely passed through off-center. That detail matters: the path of an encounter helps determine the structures left behind. These galaxies are in the process of merging, with hundreds of millions of years of change still ahead.
It is a strange scale to sit with. We can study the shape in a moment, while the event responsible for it extends far beyond a human lifetime.
Follow the faint bridge
This Webb view combines observations from NIRCam, its Near-Infrared Camera, and MIRI, its Mid-Infrared Instrument. Together they reveal different parts of the same scene.
The near-infrared observations bring out older stars and a delicate bridge of stars and gas between the galaxies. The orange and red regions in the composite highlight areas associated with young stars and star formation in the mid-infrared data.
Look for that bridge before returning to the brighter curve. It is easy to miss beside the stronger shapes, yet it makes the relationship between the galaxies much easier to imagine.
Reading the colors
The colors translate infrared measurements into a visible image. Different filters receive different hues, allowing structures observed at different wavelengths to appear together. This is a way of seeing information our eyes cannot collect on their own.
For me, knowing that makes the image more interesting. The warm curve is immediately inviting, and the quieter details give you a reason to keep looking.
A conversation across the room
Arp 107 would be a natural conversation piece above a desk or in a reading space. You might begin by pointing out the smile, then find yourself talking about the bridge and the long encounter behind it.
Explore our Arp 107 print to see the available presentations.
Clear skies,
D.R. Skywalker
Image credit: NASA, ESA, CSA, STScI. Image processing: M. Garcia Marin and Alyssa Pagan (STScI).
Sources: NASA’s account of the Arp 107 encounter; NIRCam and MIRI image details and credits.