NGC 7129, a Complex Nebula in Cepheus

Posted by Rod Pommier
on Monday, December 14, 2020
NGC 7129 is a dim nebula in the constellation Cepheus. It is remarkable in that it exhibits four different types of nebulae. Central regions of it are an emission nebula emitting red light of the hydrogen-alpha wavelength due to ultraviolet light from its central stars ionizing surrounding hydrogen gas. But most of it is a blue reflection nebula as a result of dust scattering blue light from those same stars, much as scattered sunlight in our atmosphere makes the sky blue. Still other portions of it are dark nebulae due to dust clouds obscuring what is behind them. But that is not all. NGC 7129 exhibits several bright red Herbig-Haro objects where very young stars are still in the process of forming. NGC 7129 lies 3,300 light years from Earth.

Image Data:
Telescope/Mount: Celestron Compustar C14 with Starizona LF reducer/corrector (f/7.5)
Camera: SBIG STL 11000M with Baader Planetarium Ha,L,R,G,and B filters
Adaptive Optics: SBIG AO-L at 8 Hz
Location: Pommier Observatory, Portland, OR, USA
Dates: 2018-10-12 through 2018-10-19
Exposures: Ha:L:R:G:B=870:460:200:190:190 = 28 hours, 40 minutes total exposure.

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