Wednesday, 12 September 2012

The Ant Shaped Nebula

The Ant Nebula, aka Mz3, is a young bipolar planetary nebula in the constellation Norma. It is 8,000 light years away from Earth and it has a magnitude of 13.8. It was discovered by Donald Howard Menzel in 1922. The nebula is composed of a bright core and four high-velocity outflows which have been variously named as lobes, columns, rays, and chakram. The gas being ejected travels at 1000-kilometres per second and the structure is one light year long.

So why is this nebula an odd shape? There are a couple of possibilities.

  1. One is that the central star of Mz3 has a companion orbiting closely that is exerting strong gravitational forces, shaping the out flowing gas. 
  2. The second possibility is that the strong magnetic fields are being wound into complex shapes by the spin of the dying star. 
No other planetary nebula observed by Hubble closely resembles Mz3. M2-9 comes close, but M2-9 has prominent hydrogen emission lines in the near infra-red whereas Mz3 has no trace of molecular hydrogen emission.

Photo: THE ANT NEBULA

The Ant Nebula, aka Mz3, is a young bipolar planetary nebula in the constellation Norma. It is 8,000 light years away from Earth and it has a magnitude of 13.8. It was discovered by Donald Howard Menzel in 1922. The nebula is composed of a bright core and four high-velocity outflows which have been variously named as lobes, columns, rays, and chakram. The gas being ejected travels at 1000-kilometres per second and the structure is one light year long. 

So why is this nebula an odd shape? There are a couple of possibilities. One is that the central star of Mz3 has a companion orbiting closely that is exerting strong gravitational forces, shaping the out flowing gas. The second possibility is that the strong magnetic fields are being wound into complex shapes by the spin of the dying star. No other planetary nebula observed by Hubble closely resembles Mz3. M2-9 comes close, but M2-9 has prominent hydrogen emission lines in the near infra-red whereas Mz3 has no trace of molecular hydrogen emission. 

-TEL

Post on M2-9: https://www.facebook.com/photo.php?fbid=403358193062692&set=a.334832996581879.82450.334816523250193&type=3&theater

http://apod.nasa.gov/apod/ap050501.html; http://heritage.stsci.edu/2001/05/caption.html
Photo: R. Sahai (JPL) et al., Hubble Heritage Team, ESA, NASA

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