ISOSS J20180+6345 , the SIMBAD biblio

Small isolated clouds were discovered by the ISOPHOT 170µm Serendipity Survey (ISOSS) as faint I₁₇₀<13MJy/sr FIR sources. One of them is ISOSS J20246+6540, a cold (T_d≃14.5K) pointlike ISOSS source without an IRAS pointsource counterpart. In the Digitized Sky Survey B band it is seen as a 3'size bipolar nebulosity with an average excess DSS blue band surface brightness of 8% of the background's photographical density. The CO column density distribution determined by multi-isotopic, multi-level CO measurements with the IRAM-30m telescope agrees well with the optical appearance. An average hydrogen column density of ≃10²¹cm^–2 was derived from both the FIR and CO data. Using a kinematic distance estimate of 400pc the NLTE modelling of the CO, HCO⁺, and CS measurements gives a peak density of ≃10⁴cm^–3. The multiwavelength data characterise ISOSS J20246+6540 as a representative of a class of globules which has not been discovered so far due to their small angular size and low 100µm brightness. A significant overabundance of ¹³CO is found X(¹³CO)≥150xX(C¹⁸O). This is likely due to isotope selective chemical processes.