Consequently, they are less likely to be associated with bipolar outflows.

In both cases, bipolar outflows consist largely of molecular gas.

They may play an important role in creating the bipolar outflow in the region.

Bipolar outflows are often found in dense, dark clouds.

In the case of a young star, the bipolar outflow is driven by a dense, collimated jet.

A bipolar outflow represents two continuous flows of gas from the poles of a star.

It would appear that such high speeds can only arise if the dust grains had been ejected by a bipolar outflow close to the star.

The bipolar outflows in the image indicate that the system has angular momentum, which is very likely generated by an accretion disc.

Indeed, the bow shocks are thought to sweep up or "entrain" dense gas from the surrounding cloud to form the bipolar outflow.

The presence of a bipolar outflow shows that the central star is still accumulating material from the surrounding cloud via an accretion disk.

The bipolar outflows from post-AGB stars eventually grow to form a planetary nebula.

They sweep up or "entrain" the surrounding dense molecular gas to form a continuous flow of material, which is referred to as a bipolar outflow.

It is distinguished from the bipolar outflows characteristic of young stars by being less collimated, although stellar winds are not generally spherically symmetric.

We suggest that the high-velocity maser emission in NGC4258 might be from masers orbiting a massive central black hole, or ejected in a bipolar outflow.

Bipolar outflows may be associated with protostars (young, forming stars), or with evolved post-AGB stars (often in the form of bipolar nebulae).

He is perhaps best known for his discovery, with Guillermo Haro, of the Herbig-Haro objects; bright patches of nebulosity excited by bipolar outflow from a star being born.

This led the team of astronomers to speculate that the bipolar outflow from the young star may be transporting the forsterite crystals from near the star's surface to the chilly outer cloud.

M82's unique bipolar outflow (or 'superwind') appears to be concentrated on clumps A and C and fueled by the energy injected by supernova that occur about once every ten years.

YSO are also associated with early star evolution phenomena: polar jets and bipolar outflows, masers, Herbig-Haro objects, protoplanetary disks (circumstellar disks or proplyds).

Bipolar outflows are usually observed in emission from warm carbon monoxide molecules with millimeter-wave telescopes like the James Clerk Maxwell Telescope, though other trace molecules can be used.

Bipolar outflows from evolved stars probably start out as spherically-symmetric winds (called post-AGB winds), ejected from the surface of a red giant star as it cools and fades.

Though the exact causes of this nebular structure are not known, it may be related to the physical process known as bipolar outflow in which a star ejects highly energetic streams of outflow along both poles.

The bipolar outflow model does however raise the question of how molecules can survive in a strong shock in a medium with the extremely high velocity of 1,000km s -1 (for comparison, the sound velocity in interstellar space is only a few kilometres per second).

It is speculated that Sher 25 is near the point of going supernova, as it has recently thrown off matter in a pattern similar to that of supernova 1987A in the Large Magellanic Cloud, with a circumstellar ring and bipolar outflow filaments.