The Caldwell Objects

One other thing adds to the cluster's specterlike
quality. Radio and optical observations of the
cluster have revealed a 45'-wide supernova
remnant (G127.1+0.5 R5) centered on a bright
radio source at right ascension 01 h 25 m 00 s and
declination +62° 55'. Radio observations show the
remnant to have a distinct shell. According to A
Catalogue of Galactic Supernova Remnants by David
A. Green (Mullard Radio Astronomy
Observatory, England, 1998), the
The Caldwell Objects
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relationship between the supernova remnant and
NGC 559 is still under investigation. If the two
are associated, the remnant would span nearly 50
light-years of space, which is five times larger
than the cluster's true physical diameter. At face
value, however, any association seems highly
implausible, since the remnant appears to have
been expanding for only 18,000 years — making
it fully 100,000 times younger than the cluster.
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