NGC 3918 in Centaurus
0.4 light years.
4,300 light years.
|Apparent size: |
0.3 arc min
|Field of View:|
18.7 x 12.7 arcmin
|Image date: |
Also known as “The Southerner”
If I had a much bigger astronomy budget or maybe if I could suddenly become a professional astronomer, then planetary nebulae are the objects which I would choose to study. They consist of gas ejected from dying stars and they are typically somewhat bigger than the Solar System in diameter.
With some notable exceptions, most planetary nebulae appear quite small in an amateur telescope, so they don’t always make the most captivating of images. However, every planetary nebula has evolved differently and will look unique and exquisite in images obtained by the largest professional telescopes.
The Blue Planetary nebula appears quite small at 0.3 arc minutes (one two hundredth of a degree) and my image only picks out the central core of the nebula.
A Previous Image
I’ve imaged it before using a DSLR on an 8″ Schmidt-Cassegrain telescope and the images both look somewhat similar: a small blue disc. This is an old one from 2009:
It’s actually much more than a blue circle. Its Hubble picture is remarkable and reveals far more of the very faint detail in the nebula.
Location of the Centaurus constellation in the whole sky:
Location of the Blue Planetary Nebula near the Southern Cross:
Sometimes the Astrometry website is off line and the Astrometry images will not appear .
Thanks for reading 🙃
Telescope & Imaging Details
|Telescope:||SkyWatcher Esprit 120 mm apochromatic 3-element refractor; 840 mm f/l @ f/7.|
|Optics:||Field flattener; ZWO Duo-band Hα (656nm) and [OIII] (500nm) filter.|
|Mount & Guiding:||SkyWatcher EQ6-R Pro mount; ZWO ASI120 guide camera.|
|Imaging camera:||ZWO ASI 290 MC|
|Software:||Control: Cartes du Ciel, ASCOM, EQMOD, PHD2. Imaging: SharpCap, Gimp.|
Images © Roger Powell
I’m one of the founder members of Macarthur Astronomical Society and current webmaster.