... Comet Hartley Passes a Double Star Cluster . ... Open clusters NGC 869 and NGC 884, however, are doubly impressive. Also known as "h and chi Persei", this unusual double cluster , shown above, is bright enough to be seen from a dark location without even binoculars . ... Captured earlier this month, the bright comet 103P/Hartley , informally called Comet Hartley 2, passed well in front but only a few degrees away from the famous double cluster. ... M7: Open Star Cluster in Scorpius . ...