Lynds Bright Nebula 691 (MBM 32) Hartz Nagusian dagoen hodei molekularra, gure galaxian dauden altitude handiko gune trinkoetako bat da. Hodei mokelularra, izar-arteko hodei mota bat da non bertan molekulak sortzeko nahikoa dentsitate eta tamaina dituen, gehienetan H2. MBM 32 hodei molekularra lehenik LBN 691 bezala katalogatua izan 1965an eta ondoren MBM 32 bezala 1985an. Hartz Nagusiko Hodei Molekular konplexuan kokaturik dago eta bertan lehen aldiz H2CO eta NH3 konposatu kimikoak antzeman zituzten.

Lynds Bright Nebula 691 (MBM 32) is a molecular cloud in Ursa Major, a dense core of high galactic cirrus cloud. A molecular cloud, is a type of interstellar cloud, the density and size of which permit the formation of molecules, most commonly molecular hydrogen (H2). The molecular cloud MBM 32 was first catalogued as LBN 691 by Lynds (1965) and later as MBM32 by MBM (1985). It is located in the complex known as the Ursa Major cirrus cloud. This cloud is one of the first cirrus clouds where H2CO and NH3 organic compounds were detected.