A&A 617, A42 (2018) https://doi.org/10.1051/0004-6361/201833196 Astronomy & © ESO 2018 Astrophysics Optical and UV surface brightness of translucent dark nebulae ? Dust albedo, radiation field, and fluorescence emission by H2 K. Mattila1, M. Haas2, L. K. Haikala3, Y-S. Jo4, K. Lehtinen1,8, Ch. Leinert5, and P. Väisänen6,7 1 Department of Physics, University of Helsinki, PO Box 64, 00014 Helsinki, Finland e-mail:
[email protected] 2 Astronomisches Institut, Ruhr-Universität Bochum, Universitätsstrasse 150, 44801 Bochum, Germany 3 Instituto de Astronomía y Ciencias Planetarias de Atacama, Universidad de Atacama, Copayapu 485, Copiapo, Chile 4 Korea Astronomy and Space Science Institute (KASI), 776 Daedeokdae-ro, Yuseong-gu, Daejeon 305-348, Korea 5 Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany 6 South African Astronomical Observatory, PO Box 9 Observatory, Cape Town, South Africa 7 Southern African Large Telescope, PO Box 9 Observatory, Cape Town, South Africa 8 Finnish Geospatial Research Institute FGI, Geodeetinrinne 2, 02430 Masala, Finland Received 9 April 2018 / Accepted 27 May 2018 ABSTRACT Context. Dark nebulae display a surface brightness because dust grains scatter light of the general interstellar radiation field (ISRF). High-galactic-latitudes dark nebulae are seen as bright nebulae when surrounded by transparent areas which have less scattered light from the general galactic dust layer. Aims. Photometry of the bright dark nebulae LDN 1780, LDN 1642, and LBN 406 shall be used to derive scattering properties of dust and to investigate the presence of UV fluorescence emission by molecular hydrogen and the extended red emission (ERE).