The Euclid Consortium wishes everyone joyful holidays at the end of 2025!
NGC 646 is a large barred spiral galaxy located in the constellation Hydrus. It was discovered in 1834 by the British astronomer John Herschel and has recently been observed by the Euclid space telescope. The galaxy is moving away from us at a speed of about 8,145 km/s, which corresponds to a distance of roughly 120 ± 8 megaparsecs, or about 392 million light-years.
Although this may seem very far, NGC 646 is actually quite close compared to the billions of galaxies that Euclid will observe during its six-year mission. By the end of 2026, the European Space Agency (ESA) and the Euclid Consortium will release the first year of its observations, corresponding to 2,500 square degrees. These images will show hundreds of thousands of galaxies in exquisite detail, marking an important milestone in the history of astrophysics. Along with many other scientific investigations, this unprecedented dataset will help scientists deeply understand how galaxies form and evolve, including why such barred galaxies become more common as the Universe ages.
In images, NGC 646 appears close to a smaller galaxy to its east, called PGC 6014. However, PGC 6014 is at a distance of about 106 ± 7 megaparsecs (around 347 million light-years). This means that the two galaxies are actually separated by about 45 million light-years, even though they look like neighbors in the sky. As a result, any gravitational interaction between them, if it exists at all, would be very weak and short-lived.
