Sh2 -261 , also sometimes known as the Lower Nebula , is avisible emission nebula in the constellation of Orion .

It is located in the northernmost part of the constellation, about 6 ° west of Alhena (γ Geminorum); it is easily visible in long exposure photos taken even with medium power amateur instruments. It lies in the clear trail of the Milky Way in opposition to the galactic centerand is surrounded by rich background star fields. The best period for its observation in the evening sky falls in the months between January and May, and although it is located in the northern celestial hemisphere , it can be observed from all populated areas of the Earth.