Star formation in the filament of S254-S258 OB complex: a cluster in the process of being createdM. R. Samal, D. K. Ojha, J. Jose, A. Zavagno, S. Takahashi, B. Neichel, J. S. Kim, N. Chauhan, A. K. Pandey, I. Zinchenko, M. Tamura and S. K. GhoshA&A, 581 (2015) A5DOI: https://doi.org/10.1051/0004-6361/201322787