M29, The Cooling Tower Cluster with reflection/emission nebulosity in HaRGB (Cygnus) - Oct 2022
Planewave CDK12.5 - AIS6200MM
A-P 1100 GTO AE, Antlia Pro 3nm NB & BB filters
Ha filters: (17 x 420s exposures, Bin 2x2, Gain 200)
R,G,B filters (3 x 38 x 180s exposures, Bin 2x2, Gain 100)
Total Integration Time = 7.68 hours
The Cooling Tower is an open cluster defined by 6 giant stars in the shape of a cooling tower, as if it was lit-up at night. The 6 stars are all brighter than magnitude 9.5, 5 of which are class B0 red stars (airplane warning lights for the cooling tower), while one is a blue star forming the odd man out.
M29 is also associated with nebulosity, some of which is reflecting (blue) light from the cooling tower, while most consists of hydrogen emission nebulosity. Both red and blue channels were augmented with Ha signal (also a sub for Hb) to bring out this predominantly red nebulosity. There is a lot of dark nebulosity on the LHS of the image as well.
The cluster is between 4,000 and 7200 ly away - the large uncertainly results from an unknown degree of star dimming caused by the nebulosity. The age is approximantely 13MMyrs making the cluster much younger than our sun.