Another lovely wide field Bert, despite the sleep deprivation.
As for the red cluster found out it's Westerlund 1.
And ripped from wiki... (NOTE: don't try the hyperlinks, they won't work).
Westerlund 1 (sometimes abbreviated
Wd1) is the most massive compact young
star cluster known in the
local group of galaxies and is about 3.5-5
kpc away from Earth. It was discovered by Bengt Westerlund in 1961
[1] but remained largely unstudied for many years due to high
interstellar extinction (absorption) in its direction.
The cluster contains a large number of rare, evolved high-mass stars including 6
yellow hypergiants, 4
red supergiants, 24
Wolf-Rayet stars, a
luminous blue variable, many
OB supergiants and an unusual
sgB[e] star that has been proposed as the remnant of a recent stellar merger
[2]. In addition,
X-ray observations have revealed the presence of the
magnetar CXO J164710.2-455216 (also known as the Westerlund 1 magnetar), a slow X-ray
pulsar that must have formed from a high-mass progenitor star
[3][4]. Westerlund 1 is believed to have formed in a single burst of star formation, implying the constituent stars have the same age and composition.
Besides hosting some of the most massive and least-understood stars in the galaxy, it is useful as an analog to help astronomers determine what occurs within extragalactic
super star clusters.
The brightest O7-8V
main sequence stars in Wd1 have
V-band photometric magnitudes around 20.5, and therefore at visual wavelengths Wd1 is dominated by highly luminous post-Main Sequence stars (V-band magnitudes of 14.5-18,
absolute magnitudes -7 to -10), along with less-luminous post-Main Sequence stars of
luminosity class Ib and II (V-band magnitudes of 18-20). Due to the extremely high interstellar reddening towards Wd1, it is very difficult to observe in the U- and B-bands, and most observations are made in the R- or I-bands at the red end of the spectrum or in the
infra red. Stars in the cluster are generally named using a classification introduced by Westerlund
[5], although a separate naming convention is often used for the Wolf-Rayet stars.
Very interesting, active region.
Nice place to visit but you wouldn't want to live there.
Justin