created: 04-10-2014.       revised: 04-16-2015.

In 1958, Czech astronomer Jaroslav Ruprecht, (1931 - 2011), published a paper, (of which he was one of the main compilers), of all known stellar associations, open star clusters, and globular clusters called "Catalogue of Star Clusters and Associations". Within this catalog, there are a total of 176 new open clusters.

                        Byurakan Observatory

The amateur astronomer will find many of his 'Ruprecht' objects listed on star atlases and observing guides. While a very few of the 'Ruprecht' objects are already listed under other catalog designations such as 'NGC', the majority are unique objects, not listed in any other prior catalog. Ruprecht clusters can be found along the entire length of the Milky-Way, but there’s a nice ‘clustering’ of them along the Winter Milky-Way in Canis Major and Puppis.


Ruprecht 147 (NGC 6774), is particularly interesting in that it is only 800 to 1,000 light-years from Earth, and it's component stars, which were born out of the same cloud of gas and dust, are approximately 2-billion years old, making it the closest star cluster to Earth that have member stars similar to the Sun’s mass and age than those in all the other nearby clusters. Astronomers have identified this cluster as a potentially important new reference gauge for fundamental stellar astrophysics, and will become very useful in understanding the evolution of stars like the Sun, and in the search for Earth-like planets orbiting around Sun-like stars.

On the left side of the webpage is my personal observation list of the
'Ruprecht catalog of star clusters'.

I currently have all 90 possible cluster objects visible from my Pittsburgh, PA latitude of around +40.
(86 of the '176' total objects are not observable from my area, and Ru-9 is a asterism and not a true cluster).

Hope you enjoyed the visit. Come again soon!
Larry McHenry,   Pittsburgh, PA. USA

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