ESO’s Very Large Telescope (VLT) has delivered an unrivalled snapshot of the spiral galaxy Messier 77.
This image shows the barred spiral galaxy Messier 77, which lies in the constellation Cetus, about 62 million light-years away. Image credit: ESO.
Messier 77, also known as NGC 1068, LEDA 10266 and Cetus A, is a barred spiral galaxy located in the constellation Cetus.
It has an apparent magnitude of 9.6 and lies at a distance of 62 million light-years.
Messier 77 was discovered by French astronomer Pierre Méchain in 1780, who originally identified it as a nebula. Méchain then communicated the discovery to his colleague, French astronomer Charles Messier.
Messier believed that the highly luminous object he saw was a cluster of stars, but as technology progressed its true status as a galaxy was realized.
At 100,000 light-years across, Messier 77 is one of largest galaxies in the Messier catalogue — so massive that its gravity causes other nearby galaxies to twist and become warped.
It is also one of the closest galaxies with an active galactic nucleus (AGN).
Such active galaxies are among the brightest objects in the Universe and emit light at most, if not all, wavelengths, from gamma rays and X-rays all the way to microwaves and radiowaves.
Messier 77 is also a Type II Seyfert galaxy, characterised by being particularly bright at infrared wavelengths.
This new image is made up of observations from VLT’s FOcal Reducer and low dispersion Spectrograph 2 (FORS2) instrument in four different wavelength bands (blue, red, violet and pink).
Each wavelength brings out a different quality: for example, the pinkish hydrogen-alpha highlights the hotter and younger stars forming in the spiral arms, while in red are the fine, thread-like filamentary structures in the gas surrounding Messier 77.
A foreground Milky Way star is also seen beside the galaxy center, displaying tell-tale diffraction spikes.
Additionally, many more distant galaxies are visible; sitting at the outskirts of the spiral arms, they appear tiny and delicate compared to the colossal active galaxy.
