ARCturus

The magazine Tähdet ja Avaruus, issue 1/2012, breaks the news of a planetary nebula in a spherical cluster of stars. The photo of Hubble Heritage Image Gallery, in November 2011,  has been taken of a cluster of stars, NGC 1846, which is in the Great Magellanic Cloud. In the middle of the photo there is a greenish patch. Other bright stars in the cluster are red or blue. The green colour is caused by the filter used in the phographing process.

Source:Tähdet ja Avaruus 1/2012, Ursa Astronomical Association

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