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.
Designation: Caldwell 80, NGC 5139.
Visual magnitude: +3.7
Apparent size: 55′
Diameter: 271 light years.
Distance: 17,000 light years.
Altitude: 67° above SE horizon.
Exposure: 14.75 min. (10 frames @ 88.5 sec).
Location: The Oaks, NSW, semi-dark rural.
Moon: rose at 9.22 pm. imaging ceased 9.27 pm.
Sky: 0.50 e/pixel/s.
Image acquisition software: SharpCap, live stacked.
Image post-processing: GIMP.
Cropping: two edges, to centre the object.
|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:
[ZWO ASI071MC Pro]
Output Format=FITS files (*.fits)
Frame Rate Limit=Maximum
White Bal (B)=50
White Bal (R)=53
Auto Exp Max Gain=300
Auto Exp Max Exp M S=30000
Auto Exp Target Brightness=100
Anti Dew Heater=Off
Display Black Point=0
Display MidTone Point=0.5
Display White Point=1
Image © Roger Powell