|Designation: NGC 3211, in southern constellation of Carina.|
|Visual magnitude: +10.7|
|Apparent size: 0.3 arc-minutes.|
|Diameter: 0.5 light years.|
|Distance: 6,700 light years.|
|Date: 2020-03-19, clear sky, no Moon.|
|Exposure: 35 x 174 sec = 101 min.|
Not all astronomical objects are big enough and beautiful enough to fill a whole image. Some can be very small – but it’s a pleasure to find and capture planetary nebulae on camera.
They may not always make much of an impact picture but most planetary nebula are visually small – and this one is particularly so, just one third of an arc minute in diameter. It’s as much about what they are as it is about how magnified they are.
NGC 3211 is the turquoise coloured object, dead centre of the image, the remains of a distant solar system where the star has reached the end of its cycle, blown off its outer layers and the resultant ring of gas is no longer just a point source of light.
Its diameter of 0.5 of a light year means that eight of them could fit side by side between the Sun and our nearest star system, Alpha Centauri.
When the bright object near the top started to appear during live stacking I wondered whether it was a galaxy but it turned out to be the magnitude 7.0 star HD89203, a blue/white B class giant just 1042 light years away. The surrounding fuzz is probably just local atmospheric refraction.
Follow this link to see my image annotated by Astrometry.net, who inform that the image is cropped to 38.9 x 38.9 arc-minutes with the orientation: “Up is 90.8 degrees E of N”.
|SkyWatcher Esprit 120 mm apochromatic 3-element refractor.|
|840 mm focal length @ f/7 with field flattener.|
|Baader L-Booster UHC-S light pollution filter 2458276.|
|SkyWatcher EQ6-R Pro mount.|
|Camera: ZWO ASI 071 MC Pro (CMOS 28.4mm 16 Mpx)|
|ZWO ASI120 guide camera, using PHD2 software.|