Study of magnetic field geometry and extinction in Bok globule CB130
  We trace the peripheral magnetic field structure of Bok globule CB130, by
estimating the linear polarization of its field stars in the R band. The
magnetic field orientation sampled by these stars, aligned on average among
themselves and the polarization produced within the cloud has a different
direction from that of Galactic plane with an offset of 53$^\circ$. The offset
between minor axis and the mean magnetic field of CB130 is found to be
80$^\circ$. The estimated strength of the magnetic field in the
plane-of-the-sky is $\sim$ 116$\pm$19 $\mu$G. We constructed the visual
extinction map using Near Infrared Color Excess (NICE) method to see the dust
distribution around CB130. Contours of Herschel {Herschel is an ESA space
observatory with science instruments provided by European-led Principal
Investigator consortia and with important participation from NASA} SPIRE
500$\mu$m dust continuum emission maps of this cloud is over-plotted on the
visual extinction map which shows the regions having higher optical extinction
corresponds to higher densities of dust. Three distinct high dust density cores
(named as C1, C2, and C3) are identified in the extinction map. It is observed
that the cores C1 and C3 located close to two previously known cores CB130-1
and CB130-2 respectively. Estimate of visual extinction of some moderately
obscured stars of CB130 are made utilizing near-infra red photometry. Its
observed that there is a feeble dependence of polarization on extinction; and
polarization efficiency (defined as $ \textit{p}$/A$ {V}$) of the dust grains
decreases with the increase in extinction.
