The darkness of the Horsehead is caused mostly by thick dust , although the lower part of the Horsehead's neck casts a shadow to the left. Streams of gas leaving the nebula are funneled by a strong magnetic field . Bright spots in the Horsehead Nebula 's base are young stars just in the process of forming . Light takes about 1500 years to reach us from the Horsehead Nebula. The above image was taken with the 0.9-meter telescope at Kitt Peak National Observatory .
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