Eta Carinae Nebula

[AusGuy]

The Eta Carinae Nebula is so big and bright that it is an easy naked eye object provided that local light pollution is not too bad. The best view of this object that I have ever had was at the eyepiece of a little 5 inch Newtonian some years ago. The sparkling display of star clusters was dazzling and the structure of the nebulosity was very well defined. Of course – no colour. Fast forward to now and a live stack of 15 second exposures easily produces all the colour that you can want albeit at the expense of star sparkle. This view of the inner part of the nebula was snapped last night before the clouds rolled in. Hope you like it.

Vixen R200SS; SW AZ-EQ6; ZWO ASI294MC Pro cooled to -10C; Baader MPCC

SharpCap live-stacks at 500 gain. Adjusted in StarTools.

And a little adjustment using StarTools maybe better brings out some of the details. Eta Carina is the large over-exposed star near the bottom of the frame. The Keyhole Nebula is just below it to its left.

David

Edited January 13, 2021 by AusGuy

[Mike JW]

Hi David, wonderful to see this. I shall never see it for real. Mike

[AusGuy]

Never say never Mike.

Since an image of M42/M43 occupies just about as much real estate in my camera frame as this image of the Eta Carinae Nebula, its tempting to think of the two nebulae as being roughly the same size. But while M42 is about 1,500 light years away the Eta Carinae Nebula is 5 times further away at about 7,500 light years. So the Eta Carinae Nebula is much the bigger of the two. Knowing the angular dimensions of my camera frame and applying a little basic trigonometry I calculate that the part of the Eta Carinae Nebula shown in the image spans 176 light years horizontally and 123 light years vertically. The diameter of the round Keyhole Nebula is 6½ light years and so from one side to the other it is a bit larger than the 4 light years distance from us to our nearest star Alpha Centauri and yet, you can see that the Keyhole is packed with nebulosity and stars. What would our skies look like if we were located at its centre? Even the little dark squiggly dust pillar complex extending out from the cold dark gas and dust cloud at 8 o'clock from the Keyhole is 5½ light years long and so is a bit larger than the 4 light years Pillars of Creation in the Eagle Nebula M16. This is a land of giants.