IC 348 – Open Star Cluster Plus Nebula – Perseus – January 2021 Observer’s Challenge Report #144
Compiled by:
Roger Ivester, North Carolina
&
Sue French, New York
January 2021
Report #144
IC 348 – Cluster plus Nebula in Perseus
Sharing Observations and Bringing Amateur Astronomers Together
This month’s target
During his term as the first director of Dearborn Observatory, Truman Henry Safford discovered IC 348 on December 1, 1866, with the observatory’s 18.5-inch refractor. Safford published his observation in a table of objects found at Dearborn in the years 1866–1868. The table uses the alphabet-soup notation common to the era, which decrypted means: very large, very gradually brighter in the middle, pretty bright. Additionally, a note below that section of the table describes the object as “A loose cluster with nebula.” The combo appeared in the First Index Catalogue.
IC 348 has the dubious honor of bearing two IC designations. Edward Emerson Barnard independently discovered the nebula in 1893, and it was placed in the Second Index Calalogue as IC 1985, without anyone tumbling to the fact that it was already in the previous IC catalog. Unlike Safford, Barnard didn’t note the existence of the cluster within the nebula.
IC 348 is thought to be roughly 1000 light-years away and a youthful 2–3 million years old. It holds about 500 stars, with brightest being hot, blue-white stars on the main sequence. The cluster’s visual magnitude is 7.3. By Sue French
