Sh2-239 within LDN 1555

 

 

 

 

Sh2-139 is an interesting object that is located in the dark cloud LDN 1555, just like NGC 1555, the Hind’s Variable Nebula, that surrounds the star T Tau. This region is a frantic star forming area what means that it is not surprising to find Herbig-Haro objects in the field. Accordingly, this image contains four Herbig-Haro objects, HH 28, HH 29, HH 30 and HH 102 (see annotated version below). All four Herbig-Haro objects are interesting. In 1992, Vera Rubin and J. Graham describe that L 1555-IRS 5, a strong infrared/radio source, still embedded in the nebula, is the responsible of the illumination of the reflection nebula HH 102 (center of the image). They also study two Herbig Haro objects in this region (HH 28 and HH 29) to determine whether two faint clouds to the NE (upper left in this image) are the counterparts of these two HHs, which they confirmed it was the case.

Recently (2025) the James Webb Space telescope (JWST) imaged HH 30 with a stunning resolution.