What is Westerlund 1?
Q: What is Westerlund 1?
A: Westerlund 1 (Wd1, also called Ara Cluster) is a compact young super star cluster located in the Milky Way galaxy.
Q: How far away from Earth is it?
A: Westerlund 1 is approximately 3.5–5 kiloparsecs (12000–16000 light years) away from Earth.
Q: Who discovered it?
A: It was discovered by Bengt Westerlund in 1961.
Q: What type of stars does it contain?
A: The cluster contains a large number of rare, evolved, high-mass stars, including six yellow hypergiants, four red supergiants, 24 Wolf-Rayet stars, a luminous blue variable, many OB supergiants, and an unusual supergiant sgB[e] star which may be the remnant of a recent stellar merger.
Q: What will happen to Westerlund 1 in the future?
A: In the future, it will probably evolve into a globular cluster.
Q: Why is this cluster useful to astronomers?
A: Apart from hosting some of the most massive and least-understood stars in the galaxy, Westerlund 1 is useful as an example of a relatively nearby and easier to observe super star cluster that can help astronomers find out what happens in extragalactic super star clusters.
Q: What type of object has been detected through X-ray observations at this location?
A: X-ray observations have revealed the presence of a strange X-ray pulsar; a slow rotating neutron star that must have formed from a high-mass progenitor star.
