NGC 3372 Carina Nebula

OTA: TAO 150 (f/7.3)

Camera: FLI - ML16200 (0.564 arcseconds/pixel: drizzled)

Observatory: Deep Sky West, Chile

EXPOSURES:

Red: 13 x 600 sec.

Blue: 11 x 600

Green: 13 x 600

L: 17 x 600 + 22 x 30 + 32 x 15 (used for HDR)

H: 14 x 900 + 11 x 300 (used for HDR)

Total exposure 12.6 hours

Image Width: ~1d 25m

Processed by Alex Woronow (2020) using PixInsight, Skylum, Topaz, SWT, starnet++

The posted image has been down-sampled to half resolution and saved as an 80% quality jpeg file.

Eta Carina Nebula, in the Sagittarius arm of our galaxy, lies approximately 8,500 ly distant. It is one of the largest known nebulae. At the grandest scale, the nebula appears to be a bipolar (two-lobe) nebula oriented perpendicular to the galactic plane. The area imaged here is at the ‘waist’ of the nebula where dark, cold dust and gas lanes pinch the nebula. The two lobes are toward the top and bottom of the image (N is down). Sir John Hershel (1840) described the complexity of the Carina Nebula: “It would be manifestly impossible by verbal description to give any just idea of the capricious forms and irregular gradations of light affected by the different branches and appendages of this nebula.”

The nebula lies within a large OB-star association and hosts numerous O-type and Wolf-Rayet young, energetic stars. Those young stars generally reside in clusters that illuminate the nebula and ionize its gases. One of the youngest known star clusters, Col 230 (Tr14) (see annotated image, B), lies within this cloud, as does the cluster Col 234 (Tr16), which hosts the star WR 25 (a Wolf-Rayet star), the most luminous star so far discovered in our Milky Way. The cluster Col 230 hosts the supergiant triple-star system HD93129. All three stars in this system are among the most luminous stars known and have masses between 70 and 110 times that of our sun with temperatures of >42,000 K. Such stars do not live long, and the A component of the triplet has already left the Main Sequence, no longer burning hydrogen, at an age of only 900,000 years.

Finally, the historic Keyhole Nebula, near the star Eta Carinae, was drawn by John Hershel in 1840 using an 18.5” telescope he brought from England to S. Africa. But his drawing appears considerably different from what recent photographs reveal (see Ref). However, since the time of the drawing, Eta Carinae underwent an immense explosion, and the debris from that explosion (creating the Homunculus Nebula) could have altered the lighting of the Keyhole Nebula. The reference below expounds on numerous other aspects of this grand and “capricious” nebula.

A useful reference: Nathan Smith, 2009, The Carina Nebula: A Laboratory for Feedback and Triggered StarFormation.