May: Two big stars in the southern hemisphere

w Centauri (NGC5139) and Centaurus A (NGC5128) are two big stars in the southern sky. Although this image from the STC Astrograph shows them seemingly close together in the sky, nothing could be further from the truth. On the left, at over 12 billion years old and with several million stars, the largest globular cluster in our galaxy. It can be seen with the naked eye and occupies an area similar to that of the Moon in the sky. It is possibly the core of a dwarf galaxy hundreds of times larger that was cannibalised by our own galaxy long ago. About 825 times further away is Centaurus A (on the right in the picture), a lenticular galaxy, the fifth brightest galaxy in the sky. It is one of the closest radio galaxies to our planet, so its active galactic nucleus has been extensively studied.

Author: Daniel López / IAC (STC Astograph - UC3)