RGB coded near-IR image of the Serpens Cloud Core star formation region observed with Arnica at the NOT in August 1996 (see Kaas 1999, AJ 118, 558 ). The field is an 8' x 6' mosaic of 4 x 3 frames in the broad band filters J (1.25 µm), H (1.65 µm), and K (2.2 µm). North is up and east is left. Only a handful of stars are optically visible in this region. Even in the near-IR very dense regions are seen as absorption of star light. Note the ridge in the NW-SE direction of apparently very dense material. Mid-IR imaging with ISOCAM shows that recent star formation essentially takes place along this ridge.
