NGC 7789, 'Carolines' Rose', or the 'White Rose' cluster.
What a lovely romantic name this cluster has.The right sort of name for
such a beautiful cluster, and a marvellous memorial to Caroline Herschel,
sister of William and aunt to John, and the discoverer of this cluster
Not only did she come to England from Germany when she was 22 to be housekeeper
for William, and vocalist for him when engaged as an organist, but she
became his assistant and was a top rate astronomer in her own right, although
often overshadowed by the fame of William and John, and responsible for
many entries in the Herschel catalogue.
In recognition of her services to astronomy, she received the gold medal
of the Royal Astronomical Society in 1828 and was made a Fellow of the
RAS in 1835, the first woman to be made a member.
She never married, and died in 1848, at the ripe old age of 98.
Her epitaph reads, 'The eyes of her who is glorified here below turned
to the starry heavens.'
The cluster is roughly 1.6 billion years old, about the time that the
first blue-green algae were forming on earth, and before the first plants.
Because of its age, it contains a lot of giant stars that are coming out
of their main sequence, and going into the red giant stage. While processing
this, I was surprised at the amount of really red stars lurking in the
It is 7,600 light years away from us, in Cassiopeia, and at a little below
magnitude 6 is easily visible in binoculars or a small telescope.
Click on image below for full size
Telescope. William Optics ZS80FD
Camera. Atik 16HR
Red. 14 x 130 seconds
Green. 13 x 160 seconds
Blue. 13 x 180 seconds
Imaged in November 2009.