The Red Rectangle Nebula is truly unusual.
Discovered quite recently in 1973 it is a proto planetary nebula in the constellation Monoceros 2300 light years from Earth, centered around the star HIP 30089. The area around the star has an unusual almost geometric shape. The Red Rectangle is not actually rectangular, but has an X-shaped structure, due to outflows of gas and dust from the star in the center.
The outflows are ejected from the star in two opposing directions, producing a shape like two conical triangles touching at their tips. There is an unusual feature that looks like rungs on a ladder which is unlike that of any other known nebula.
HIP 30089 is a dying star, currently surrounded by gas and dust, mixed with icy dust grains and hydrocarbon molecules with the nebular region spanning less than 1/3 light year. The star is still relatively cool (by star standards), it will ultimately collapse on its core and heat up and the ultraviolet radiation will cause the gases to expand and blast out into a full blown planetary nebula. The current state (at least 2300 years ago when the light began its journey towards us) gives us a rare opportunity to see a planetary nebula in the making.
Keep watching for next several thousand years and you will be able to see how things evolve.
Imaged in LRGB on my Planewave CDK 1000 at Observatorio El Sauce, Chile.
Image acquisition and Processing: Mike Selby