Abell 30 is a planetary nebula located in the constellation of Cancer, at a distance of 5,500 light years.

[1] The planetary nebula was discovered by George O. Abell in photographic plates obtained during the Palomar Sky Survey.

After having steadily produced energy for several billion years through the nuclear fusion of hydrogen into helium in its central region, or core, the star undergoes a series of energy crises related to the depletion of hydrogen and subsequent contraction of the core.

[6] Eventually the outer envelope of the red giant is ejected and moves away from the star at a relatively sedate speed of less than 100,000 miles per hour.

[7] The sequence of events – envelope ejection followed by a fast stellar wind – is repeated on a much faster scale than before, and a small-scale planetary nebula is created inside the original one.

[7] Abell 30 consists of an outer shell, a faint cloverleaf pattern, and a central star that is surrounded by knots.

The cloverleaf pattern is more pronounced towards the southeast and southwest and reaches 26 arcseconds from the centre, almost half away to the edge.

The diffuse emission is possibly the result of the material in the knots getting hit by the fast stellar wind and heated into plasma.

[14] Also, oxygen, nitrogen and neon were detected in expected quantities, while carbon abundances were elevated.

[16] Also the abundances of oxygen and nitrogen in the polar knots is about an order of magnitude lower than those observed in planetary nebula while neon is about three times less.