NGC 1156 is a dwarf

Dwarf galaxy

A dwarf galaxy is a small galaxy composed of up to several billion stars, a small number compared to our own Milky Way's 200-400 billion stars...

 irregular

Irregular galaxy

An irregular galaxy is a galaxy that does not have a distinct regular shape, like a spiral or an elliptical galaxy. The shape of an irregular galaxy is uncommon – they do not fall into any of the regular classes of the Hubble sequence, and they are often chaotic in appearance, with neither a...

 galaxy

Galaxy

A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...

 in the Aries constellation of the type Ibm. It is considered a Magellanic-type irregular. The galaxy has a larger than average core, and contains zones of contra-rotating gas. The counter-rotation is thought to be the result of tidal interactions with another gas rich galaxy some time in the past.

The AGES survey has discovered a candidate dark galaxy

Dark galaxy

A dark galaxy is a hypothetical galaxy composed of dark matter. Dark galaxies receive their name because they have no detectable stars and are theoretically invisible...

close to NGC 1156, one of only a few so far found.

It has a H II nucleus.

External links

• Arecibo Survey Produces Dark Galaxy Candidate (SpaceDaily)
• http://www.astrophotos.net/pages/GALAXIES/NGC%201156.htm
• http://www.jupiter-jp.net/~ike/English/description/N1156.htm
• http://www.ursa.fi/~sirius/cgi-bin/rade.cgi?NGC1156