Sh2-142 and NGC 7380 Description
The HII region Sh2-142 is part of an atomic and molecular cloud associated with the open star cluster NGC 7380. Estimates of distance vary from 7000 to 10,000 light years away in the Perseus arm of our very own Milky Way galaxy. The star cluster is roughly 20 light-years across, and the nebulosity roughly 100 light years across.

The cluster is young at 4 million years, centered on DH Cephei (HD215835), which is a spectroscopic binary of two massive (>30 solar masses) main-sequence O stars that are about 2 million years old. This pair of stars triggers star formation, ionizes the H II region to make it visible to us, and etches the clouds into the amazing pillars that we see here. 

DH Cephei is a detached binary, which means that the two stars evolve independently while on the main sequence,  despite a close orbit of only 2.11 days (Technically each star is within its own Roche limit, i.e. within its own gravitational control). However, they are close enough to produce tidal distortions in each other, which causes variability in their light output. And further, the pair is an X-ray source, which is thought to arise from interaction of their stellar winds.

As for star formation in the cluster , 14 of the variable stars in this cluster are young pre-main sequence (PMS) stars, while 17 are main sequence B stars. Further, some of the PMS stars in this cluster are also X-ray sources.

My Imaging
My image is a total of 72 hours exposure with Duoband narrow band filters: 43 hours using my L-eXtreme HO filter and 29 hours with my new IDAS NB3 SO DuoBand filter. This is my first light with the IDAS NB3 SO filter. It wasn't my first choice initially for a SO filter, but after waiting forever for a better option for my OSC camera, I bought the NB3 and am really so impressed with what it has shown me so far! More to come!

My Processing
Calibration/registration/stacking of all images was done in DeepSkyStacker to yield separate HOO and SOO stacks. The SII, Ha and OIII data were then separated from those stacks using StarTools.

The final OIII data was a linear combination from B and G channels of both filters, again added together in a linear combination. This turned out to be tricky since the NB3 SO filter has much wider bandpass, and thus much higher sky background, than the L-eXtreme. The final effective SHO exposures were: 29 hours SII, 43 hours Ha, and 144 hours OIII.

I used StarTools to combine the SHO data, followed by a 2x bin, background extraction, a development stretch, deconvolution, HDR and SHO Color mixing (60/40 SII/Ha,30/30/40 SII/Ha/OIII,100 OIII). For the stars, the L-eXtreme HO data was processed in StarTools. The final image was produced in PhotoShop. Stars were separated from nebulosity with StarXterminator, a multi-scale unsharp mask was done with APF-R on the nebulosity, stars were added back into the nebulosity using screen mode, and final tweaks were made for noise reduction and color.