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Object
............................................ NGC 884 & NGC 869 - "
Perseus Double open cluster "
Constellation .............................. Perseus
Distance + Ap. Magnitude....... 6800 Light Years -
4.3
Date + Time ............................... 8 / 10 /2009 -
20:15 UTC
Location .................................... "Nunki
Observatory" - Skiathos
Optics .........................................
Celestron
ED 80
Tools .......................................... Maxim
DL
Camera ..................................... SBIG ST 10
XE , AO-8
Exposure Time....................... RGB : 4 X
300 sec (each filter)
More Details ...........................
Environment Temperature : 20 oC Camera Temperature - 15
oC
Mount ....................................... Paramount
ME
Guiding .................................... Self guided
Processing Details ................ Photoshop ,
Maxim , CCDsoft
Notes ........................................ Weather:
Weather:6 /10 - Transparence: 3/6 - Humidity : 79%
Target details ......................... The
Double Cluster (also known as
Caldwell
14)
is the common name for the naked-eye
open clusters
NGC
884 (÷ Persei) and
NGC
869 (h Persei), which are close together in the constellation
Perseus. NGC
884 and NGC
869 are at distances of
7600 and
6800 light-years away,
respectively, so they are also close to one another in space. The
clusters' ages, based on their individual stars, are relatively
young. NGC
869 is
5.6 million years old
and NGC
884 is
3.2 million years old,
according to the 2000 Sky Catalogue. In comparison, the
Pleiades have an estimated
age ranging from
75
million years to
150 million years.
There are more than
300 blue-white
super-giant stars in each of the clusters. The clusters are also
blueshifted, with NGC
869 approaching Earth
at a speed of
22 km/s
(14
mi/s) and NGC
884 approaching at a
similar speed of
21 km/s
(13
mi/s). Their hottest main sequence stars are of
spectral type B0.
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