NGC 147 is a dwarf spheroidal galaxy located in the constellation Cassiopeia, about 2.5 million light-years from Earth. Part of the Local Group, which includes our Milky Way, NGC 147 is a satellite galaxy of the Andromeda Galaxy (M31). This galaxy was first documented by astronomer John Herschel in 1829. Its low brightness and compact shape make it challenging to observe without a powerful telescope, as it blends into the background of space.
Despite its modest appearance, NGC 147 has significant scientific interest. Unlike our Milky Way, which has clear spiral arms and active star formation, NGC 147 has little gas and few new stars. Most of its stars are old, ranging from 3 to 10 billion years. This provides scientists with a “snapshot” of the early universe, as they study how stars age and evolve in these low-gas environments.
NGC 147 also has a peculiar structure compared to typical dwarf galaxies. Its stars and stellar clusters are arranged in a halo-like distribution, giving it an elongated shape, which hints at past interactions with nearby galaxies, particularly with its twin, NGC 185, and the larger Andromeda Galaxy. These interactions likely stirred up its internal structure, leaving it with a stretched shape and few star-forming materials.
Understanding NGC 147 helps astronomers piece together how galaxies form and evolve over time. By studying galaxies like it, scientists can better understand the history of the Local Group and, by extension, how galaxies might evolve in other parts of the universe.
Capture Details:
Telescope: Celestron Nexstar 8se
Reducer/Flattener: Celestron .63x Reducer/Flattener
Filter: Optolong L-Pro
Camera: ZWO ASI294 MC Pro
Mount: Skywatcher EQM-35 Pro
Total Time: 4 hours
Capture Software: N.I.N.A.
Guiding: PHD2, ZWO asi120mm mini, ZWO OAG-L
Processed in: PixInsight
Additional details on Astrobin.com.