Herman's Cross in Sagittarius
| Digital image, Venus-Moon conjunction, taken Sunday evening, December 4 at 708 PM PST from Point Fermin Park in San Pedro, CA.
Exposed to bring out the stars, you can see Alpha and Beta Capricornii at the top right. Below them the tight triangle of Rho, Pi and Omicron Capricornii appear. The moon is greatly overexposed, just showing a hint of earthlight to the upper left.
The closest appulse was in Sagittarius. If you look just below the moon, a distinctive grouping or asterism of four stars is visible. It is composed of the stars Omega, 59, 60 and 62 Sagittarii (in order of increasing right ascension). Herman Heyn of Baltimore, Md. has been labeling this cross asterism seen beneath the moon in my photo "Herman's Cross", ever since it appeared in his March, 1986 Comet Halley photos. (Click here to see a photo of Herman, Comet Halley and Herman's Cross.) An asterism is defined as an unofficial recognizable grouping
of stars. While other objects in the sky, most notably
constellations, planets and their satellites, comets, novae and
supernovae have a process of official naming by the International
Astronomical Union, asterisms do not. Groupings such as Job's
Coffin in Delphinus, The Guardians (Ursa Minor), the Big Dipper
(Ursa Major), bound clusters like Brocchi's Cluster or the
Coathanger (galactic cluster in Vulpecula), or even galaxy
groupings like Stephan's Quintet (Pegasus), acquired names from
popularizers or observers who drew attention to these aggregations
of celestial objects for one reason or another. Other names are
simply bestowed by tradition and then frequency of use. |
©2005 Derek Wallentinsen
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Derek Wallentinsen
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