Constellation Chart

The Level, The Rule

The small constellation of Norma lying in the central regions of the Milky Way, and in fact giving its name to one of our Galaxy's minor spiral arms. It contains a number of distant star clusters, but little of interest is visible to the eye.

Nebula's In Norma

MyCn18

The so-called "ant nebula" (Menzel 3, or Mz 3) resembles the head and thorax of a garden-variety ant. "ant's" body as a pair of fiery lobes protruding from a dying, Sun-like star.

By observing Sun-like stars as they approach their deaths, the Hubble image of Mz 3 — along with pictures of other planetary nebulae — shows that our Sun's fate probably will be more interesting, complex, and striking than astronomers imagined just a few years ago.

Though approaching the violence of an explosion, the ejection of gas from the dying star at the center of Mz 3 has intriguing symmetrical patterns unlike the chaotic patterns expected from an ordinary explosion. Scientists using Hubble would like to understand how a spherical star can produce such prominent, non-spherical symmetries in the gas that it ejects.

One possibility is that the central star of Mz 3 has a closely orbiting companion that exerts strong gravitational tidal forces, which shape the outflowing gas. For this to work, the orbiting companion star would have to be close to the dying star, about the distance of the Earth from the Sun. At that distance the orbiting companion star wouldn't be far outside the hugely bloated hulk of the dying star. It's even possible that the dying star has consumed its companion, which now orbits inside of it, much like the duck in the wolf's belly in the story "Peter and the Wolf."

A second possibility is that, as the dying star spins, its strong magnetic fields are wound up into complex shapes like spaghetti in an eggbeater. Charged winds moving at speeds up to 1000 kilometers per second from the star, much like those in our Sun's solar wind but millions of times denser, are able to follow the twisted field lines on their way out into space. These dense winds can be rendered visible by ultraviolet light from the hot central star or from highly supersonic collisions with the ambient gas that excites the material into florescence.

No other planetary nebula observed by Hubble resembles Mz 3 very closely. M2-9 comes close, but the outflow speeds in Mz 3 are up to 10 times larger than those of M2-9. Interestingly, the very massive, young star, Eta Carinae, shows a very similar outflow pattern.

NGC 6165

NGC 6165 is a planetary nebula, rather bright and perfectly circular with a 13 magnitude star in its centre. The planetary nebula is five degrees west-southwest of gamma2 Normae.

Cluster's In Musca

NGC 6067

NGC 6067 is a cluster of about a hundred tenth-magnitude stars. This cluster is in the same field as kappa Normae, just to the north of this star.

NGC 6087

NGC 6087 is another cluster, some 3500 light years away, comprised of forty or so stars, ranging from 7-10 magnitude. The group is two degrees east of iota1; it includes the cepheid variable S Normae.