NGC 5189

NGC 5189 (Gum 47, IC 4274, nicknamed Spiral Planetary Nebula) is a planetary nebula in the constellation Musca. It was discovered by James Dunlop on 1 July 1826, who catalogued it as Δ252.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> For many years, well into the 1960s, it was thought to be a bright emission nebula. It was Karl Gordon Henize in 1967 who first described NGC 5189 as quasi-planetary based on its spectral emissions.

Seen through the telescope it seems to have an S shape, reminiscent of a barred spiral galaxy. The S shape, together with point-symmetric knots in the nebula, have for a long time hinted to astronomers that a binary central star is present.<ref>Template:Cite journal</ref> The Hubble Space Telescope imaging analysis showed that this S shape structure is indeed two dense low-ionization regions: one moving toward the north-east and another one moving toward the south-west of the nebula,<ref name="Danehkar2018">Template:Cite journal</ref> which could be a result of a recent outburst from the central star. Observations with the Southern African Large Telescope have finally found a white dwarf companion in a 4.04 day orbit around the rare low-mass Wolf-Rayet type central star of NGC 5189.<ref>Template:Cite journal</ref> NGC 5189 is estimated to be 546 parsecs<ref name="simbad">Template:Cite simbad</ref> or 1,780 light years away from Earth. Other measurements have yielded results up to 900 parsecs (~3000 light-years).<ref>Template:Cite journal</ref>

External links

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• A Cosmic Holiday Ornament, Hubble-Style
• Southern African Large Telescope: Elusive Binary System