Clusters in the Large Magellanic Cloud

This image shows detail in a very small part of the Large Magellanic Cloud (LMC), a small satellite galaxy visible from the Southern Hemisphere.

Object Details:

Large Magellanic Cloud (LMC) mag +0.8
NGC 1856 Star Cluster (mag +10.1)
NGC 1858 Open Cluster with nebulosity (mag +9.9)
NGC 1855 Globular Cluster (mag +10.4)
NGC 1854 Open Cluster with nebulosity (mag +10.4)
NGC 1850 Globular Cluster (mag +9.0)
Constellation: Dorado.
Visual magnitude: as above
Apparent diameter of LMC: 645 x 550 arc-min. (about 20 Lunar Diameters).
Actual diameter: 29,700 light years.
Distance: 160,000 light years.
Altitude: 42° above SW horizon.

Image:

Exposure: 5 min
Date: 2018-03-11.
Location: Field night at The Oaks, NSW, with Macarthur Astronomical Society
Sky: semi-dark rural with North Easterly metropolitan sky-glow.
Cloud:  clear.
Moon: New Moon.
Image acquisition software: SharpCap.
Image post-processing:  Deep Sky Stacker > GIMP.
Cropping: no.
Saved as Fits file.

Astronomy Gear:
Imaging telescope: Skywatcher Esprit 120ED Super APO triplet refractor.
Focal length: 840 mm, focal ratio: f/7.
Imaging camera: ZWO ASI 071 MC Pro.
Guiding camera: Orion StarShoot.
Guiding control software: unguided
Guiding accuracy: n.a.
Telescope mount: SkyWatcher EQ6-R.
Polar aligning method: QHYCCD PoleMaster.
Polar alignment error:  n.a.
Field flattener: yes; filter: no.

Observing Notes:
I’ve been having poor results over the last three months due to inaccurate star alignments.  This night was no different and I also had issues with a loose lens on my Polemaster and the guide scope did not want to operate.

Spending all evening dealing with technical problems on a field night was disappointing and this shot was a last resort quick snatch, so as not to go home without at least one image. I was not even sure exactly where I was aiming and had to subsequently identify the objects in the frame.

I’ve had two observing sessions at home since then and with the alignment very erratic I need to find an opportunity to take the scope in for maintenance. So no more sessions for a while!  😦

SharpCap Camera Settings:

[ZWO ASI071MC Pro]
Debayer Preview=On
Pan=0
Tilt=0
Output Format=TIFF files (*.tif)
Binning=1
Capture Area=4944×3284
Colour Space=RAW8
Hardware Binning=Off
Turbo USB=80(Auto)
Flip=None
Frame Rate Limit=Maximum
Gain=376
Exposure=8
Timestamp Frames=On
White Bal (B)=55(Auto)
White Bal (R)=38(Auto)
Brightness=44
Temperature=15.5
Cooler Power=100
Target Temperature=-10
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=On
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=2018-03-11T11:14:04.9204590Z
SharpCapVersion=3.1.5059.0
TotalExposure(s)=288
StackedFrames=36


Image © R.Powell


 

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