THE CRISSCROSS NEBULA - AN INTERACTION OF THE ORION-ERIDANUS BUBBLE WITH A SMALL INTERSTELLAR CLOUD

A new, small (6' x 3') filamentary emission nebula of very low surface brightness (l = 197 degrees.0, b = -37 degrees.8) is found to be proj ected towards the center of a huge expanding (40 km s(-1)) H I shell ( Brown et al. 1995) surrounding the Orion-Eridanus Bubble. Moderate qua lity spectra taken by us show low-excitation species but allow us to e stimate the electron density (similar or equal to 10(2) cm(-3)). The s pectra point to an excitation by a shock of low velocity (similar or e qual to 40 km s(-1)). No dust emission (LRAS) is seen at the position of our object, which could well be an outlying clump of material assoc iated with the L1569 dust cloud at a distance of about 130 +/- 20 pc, and which appears to be at the front side of the Bubble. We believe th at our ''Criss-Cross Nebula'', dubbed so due to its specific morpholog y, might represent a very small interstellar dust cloud that is just i n the process of destruction by the blast wave of a supernova that gav e rise to the Orion-Eridanus Bubble and to some of its characteristics like the Eridanus soft X-ray enhancement. Known examples of clouds ov errun by blast waves are exceedingly rare and a more detailed study of this new nebula is therefore highly recommended.