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Object
............................................ Double
Cluster ( NGC 869 & NGC 884) - Caldwell 14
Constellation .............................. Perseus
RA / DEC
.....................................
02h:20m. /
+57°
08m.
Distance + Ap. Magnitude......... 7.500 Light years (2300
Mpc) / 3.7 & 3.8
Date + Time ............................... 4-5 & 14-15 /09/2015 -
19:00 UTC
Location ....................................
"Nunki Observatory" - Skiathos
Optics .........................................
Officina Stellare Advanced RILA 400
f/5.25
Tools ..........................................
The Sky
X - CCDAutopilot 5
Camera .....................................
SBIG STXL11002
with
FW8G-STXL (Astrodon filters)
Exposure Time....................... RGB : 3 X 300 sec (each)
More Details ...........................
Environment Temperature : 24oC Camera Temperature -30οC
Mount ....................................... Paramount
ME
Guiding .................................... Self guided
Processing Details ................ Photoshop , CCDsoft
Notes ........................................ Weather:
Partialy thin clouds Transparence: Mediun Humidity : 72%
Target details .........................
The Double Cluster (also
known as Caldwell 14) is the common name for the
naked-eye open clusters NGC 869 and NGC 884 (often
designated h Persei and χ Persei, respectively), which are close
together in the constellation Perseus. NGC 869 and NGC 884
both lie at a distance of 7500 light years. NGC 869 has a mass of
3700 solar masses and NGC 884 weighs in at 2800 solar masses;
however, later research has shown both clusters are surrounded with
a very extensive halo of stars, with a total mass for the complex of
at least 20,000 solar masses. Based on their individual stars, the
clusters are relatively young, both 12.8 million years old. 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
39 km/s (24 mi/s) and NGC 884 approaching at a similar speed
of 38 km/s (24 mi/s).Their hottest main sequence stars are of
spectral type B0.
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