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Jewel Box (star cluster)
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==Prominent members== The central part of the cluster is framed by bright stars making up an A-shaped [[asterism (astronomy)|asterism]].<ref name=southastrodel02> {{cite web |last1=James |first1=Andrew |date=22 April 2016 |title=Introduction |department=NGC 4755 : The Jewel Box "The Jewel of the South" |website=Southern astronomical delights (southastrodel.com) |url=http://www.southastrodel.com/Page002.htm |access-date=2016-04-22 }}</ref> The upper tip of this asterism is HD 111904 ([[HR 4887]], HIP 62894), a B9 supergiant and suspected variable star. It is the brightest member of the A asterism at magnitude 5.77. The brightest star in the region of the cluster is the variable [[DS Cru]] (HD 111613, HR 4876), which lies well beyond the A asterism. It is a B9.5 [[Alpha Cygni variable|α Cyg variable]] supergiant with an average visual brightness of magnitude 5.72, but is thought to be a foreground object.<ref name=kharchenko> {{cite journal |last1= Kharchenko |first1=N.V. |last2=Piskunov |first2=A.E. |last3=Röser |first3=S. |last4=Schilbach |first4=E. |last5=Scholz |first5=R.-D. |year=2004 |title= Astrophysical supplements to the ASCC-2.5 . II. Membership probabilities in 520 Galactic open cluster sky areas |journal=[[Astronomische Nachrichten]] |volume=325 |issue=9 |page=740 |doi= 10.1002/asna.200410256 |bibcode= 2004AN....325..740K }} </ref> The bar of the "A" consists of a line of four stars. On the right (south) is [[BU Crucis|BU Cru]], a magnitude 6.92 B2 supergiant and [[eclipsing binary]]. Next to it is BV Cru, a magnitude 8.662 B0.5 [[giant star|giant]] and [[Beta Cephei variable]]. Next in line is [[DU Crucis|DU Cru]], an M2 [[red supergiant]] that varies irregularly between magnitude 7.1 and 7.6 . The last of the four is CC Cru, a magnitude 7.83 B2 giant and [[Rotating ellipsoidal variable|ellipsoidal variable]].<ref name=kharchenko/> Each leg of the base of the asterism's outline is marked by a blue supergiant star. HD 111990 (HIP 62953) is magnitude 6.77 and B1/2 . The star κ Cru itself is magnitude 5.98 and B3.<ref name=kharchenko/>
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