Exploring NGC 147 and NGC 185 Galaxies Together

NGC 147 and NGC 185 from my Jade observatory

I imaged the two dwarf galaxies NGC 147 and NGC 185 from my Jade Observatory. These faint galaxies are close companions of the Andromeda Galaxy (M31) and form a gravitationally bound pair within the Local Group. Both objects are classified as dwarf spheroidal galaxies, though NGC 185 shows some unique features that distinguish it from typical members of this class.

NGC 147 is the more diffuse of the two, lacking any current star formation and showing no detectable gas. Its stellar population is predominantly old, making it an excellent example of a gas-poor, quiescent dwarf spheroidal system.

NGC 185, on the other hand, still contains dust and trace amounts of gas and even shows evidence of very low-level star formation, which is extremely rare for a dwarf spheroidal galaxy. It also hosts a population of planetary nebulae and a central concentration of dust lanes, making it scientifically intriguing.

Both galaxies are relatively close—about 2.3 million light-years away—and imaging them requires deep exposures due to their low surface brightness. Capturing the subtle structures of these companions of M31 from my Jade Observatory was both a technical challenge and a rewarding opportunity to explore two of the Local Group’s most interesting dwarf galaxies.

Data calibration, registration and the final processing was done with PixInsight. The result was as follows:

The deep exposures required to reveal these low-surface-brightness systems also bring out a wealth of background objects. In my final image, countless distant galaxies and quasars populate the field of view. The most distant quasar I identified is WISEA J003713.94+481021.0, with an impressive redshift of 3.3, corresponding to light that has traveled more than 11 billion years to reach us.