Eta Carina Nebula - Central Region Stars. This grainy shot, made at Mt Banks decades ago, captures the major star groups in the brightest part of the Nebula - a region often over-exposed. The Collinder Clusters are numbered Cr, Trumpler clusters Tr. Labelled are two extraordinary stars - Eta Car. and HD 93129A (and B) in cluster Tr 14. The latter cluster may be only half a million years old! Cluster Tr 16 is not labelled but contains the stars that surround Eta including Cr 234.
HD 93129A is often cited as the brightest, most massive star known - on an HR diagram it's always located extreme top left. This is an early type O star - something we wouldnt want for a near neighbour. Close by at the edge of Tr14 is a wide pair of O-type stars that ,in the eyepiece, are seen as a superb triple system - this is HD 93161(arrow)
The photo shows the appearance of this region as seen in an 8" or 10" 'scope from an urban setting. The dark "Keyhole" nebula looms faintly north (right) of star Eta Car. Overall an astounding part of the sky - Enjoy!