Credit: KPNO/NOIRLab/NSF/AURA.  Acknowledgments: PI: M T. Patterson (New Mexico State University) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin

This stunning image features NGC 3198, a galaxy that lies about 47 million light-years away in the constellation Ursa Major. This image was taken with the Mosaic instrument on the 4-meter Nicholas U. Mayall Telescope at Kitt Peak National Observatory, a Program of NSF NOIRLab, and shows the full extent of the galaxy, from the bright central bulge to the tenuous outer reaches of the tightly-wound spiral arms. Almost all the objects lurking in the background are galaxies or galaxy clusters — a sea of distant galaxies of all shapes, sizes, and orientations. Accurately measuring the distance to an astronomical object — everything from our own Sun to galaxies such as NGC 3198 — is an age-old challenge for astronomers, and requires a combination of measurements and methods. The galaxy at the heart of this image has played a part in this astronomical undertaking by allowing astronomers to calibrate astronomical distance measurements based on a type of variable star known as a Cepheid variable.

Provider: NOIRLab

Image Source: https://noirlab.edu/public/images/iotw2035a/

Curator: NSF's NOIRLab, Tucson, AZ, USA

Image Use Policy: Creative Commons Attribution 4.0 International License