Omega Centauri

No doubt about it – the largest, most massive and most glorious Milky Way globular cluster in the entire sky is Omega Centauri!

It is a whopper, containing about 10 million stars and a total of 4 million solar masses. It is even visible to the naked eye as a faint fuzzball about the size of the Moon if you know where to look.

Omega Centauri is technically visible from a latitude as far north as 40° N but here in the Southern Hemisphere, it is easily visible for much of the year, as is the almost as impressive 47-Tucanae, which is even further South.

I’ve imaged this stunning object several times before but this is the first time using the ZWO ASI071 camera and I was doing ok – until the Moon rose.

Object Details:

Designation: Caldwell 80, NGC 5139.
Constellation: Centaurus.
Visual magnitude:  +3.7
Apparent size:  55′
Diameter:  271 light years.
Distance:   17,000 light years.
Altitude:   67° above SE horizon.

Image:

Exposure:  14.75 min. (10 frames @ 88.5 sec).
Gain:  152.
Date:  2019-06-22.
Location:  The Oaks, NSW, semi-dark rural.
Conditions:  clear.
Moon: rose at 9.22 pm. imaging ceased 9.27 pm.
Sky:  0.50 e/pixel/s.

Processing:

Image acquisition software:  SharpCap, live stacked.
Image post-processing:  GIMP.
Cropping:   two edges, to centre the object.

Gear:

Telescope:	SkyWatcher Esprit	Type:	120ED triplet refractor
Focal:	840 mm F/7	Mount:	SkyWatcher EQ6-R Pro
Camera:	ZWO ASI 071 MC Pro	Type:	CMOS 28.4mm 16 Mpx
Optical aids:	Flattener: Y; filter: N	Guiding:	No
Polar aligning:	QHYCCD PoleMaster	Polar Error:	04’ 50”

Previous images Of Omega Centauri: 

2015-03-27  |   2016-04-27  |  2016-06-06  |  2017-07-06

Geek Log:

[ZWO ASI071MC Pro]
Debayer Preview=On
Output Format=FITS files (*.fits)
Binning=1
Capture Area=4944×3284
Colour Space=RAW16
Hardware Binning=Off
Turbo USB=40
Flip=None
Frame Rate Limit=Maximum
Gain=152
Exposure=88.5
Timestamp Frames=Off
White Bal (B)=50
White Bal (R)=53
Brightness=24
Temperature=-2.1
Cooler Power=100
Target Temperature=-15
Cooler=On
Auto Exp Max Gain=300
Auto Exp Max Exp M S=30000
Auto Exp Target Brightness=100
Mono Bin=Off
Anti Dew Heater=Off
Banding Threshold=35
Banding Suppression=0
Apply Flat=None
Subtract Dark=None
#Black Point
Display Black Point=0
#MidTone Point
Display MidTone Point=0.5
#White Point
Display White Point=1
TimeStamp=2019-06-22T11:27:15.0311484Z
SharpCapVersion=3.2.5986.0
TotalExposure(s)=885
StackedFrames=10

 

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Image © Roger Powell

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