Three distant objects, located in a nearby galaxy – the Large Magellanic cloud – 160,000 light years away in the constellations of Mensa and Dorado.
NGC 2122 (top left) is described by Safari+ as an open cluster; and by Wikipedia (Italian version) as a diffuse nebula.
My image shows it is both.
The Night Sky Observer’s Guide (vol 3) confirms this. It describes NGC 2122 as an “impressive 4′ patch of nebulosity embedded in a cluster of 11th and 12th magnitude stars loosely scattered over the glow”.
Also in the image (lower right) – approximately 42′ away across the border into the constellation of Dorado – are two adjacent open clusters NGC 2136 and NGC 2137.
Acknowledgments to Astrometry.net – I may never have identified these objects without its amazing ability. With my mount still not accurately aligning at the time, I had actually targeted a different object in the LMC and I had no idea what was in my image!
Embarrassing but true. 😳
Since taking this shot six weeks ago, the indications are that I may have resolved this persistent alignment glitch.
|NGC 2122||NGC 2136||NGC 2137|
|Diameter||209 light years||88 light years||37 light years|
|Distance||160,000 light years||160,000 light years||160,000 light years|
Altitude: approx 54° above southern horizon at time of imaging.
The brightest star (near centre) is HD 40156, a 7th magnitude double star. It is in our own galaxy, a mere 192 light years away.
Exposure: 8×30 sec = 240 sec
Date: 2019-01-04 approx 11.45 pm
Location: The Oaks, NSW.
Conditions: Mostly clear.
Sky: semi-dark rural..
Image acquisition: SharpCap live stack.
Image post-processing: GIMP.
Imaging telescope: Skywatcher Esprit 120ED Super APO triplet refractor.
Focal length: 840 mm, focal ratio: f/7.
Imaging camera: ZWO ASI 071 MC Pro
Telescope mount: SkyWatcher EQ6-R Pro.
Polar aligning method: QHYCCD PoleMaster.
Polar alignment error: 1’25”.
Field flattener: yes; filter: no.
[ZWO ASI071MC Pro]
Output Format=PNG files (*.png)
Frame Rate Limit=Maximum
White Bal (B)=54(Auto)
White Bal (R)=61(Auto)
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=0.346534653465347
Display White Point=1
Image © R.Powell