Optical Linear Polarization toward the Open Star Cluster Casado Alessi 1
  We present B-, V-, R-, and I-bands linear polarimetric observations of 73
stars in the direction of open star cluster Casado Alessi 1 (hereafter Alessi
1). We aim to use polarimetry as a tool to investigate the properties and
distribution of dust grains toward the direction of the cluster. The
polarimetric observations were carried out using the ARIES IMaging POLarimeter
mounted at the 104 cm telescope of ARIES, Nainital (India). Using the Gaia
photometric data the age and distance of the cluster are estimated to be
$0.8\pm0.1$ Gyr and $673\pm98$ pc, respectively. A total of 66 stars with a 26
arcmin radius from the cluster are identified as members of the cluster using
the astrometric approach. Out of these 66 members, 15 stars were observed
polarimetrically and found to have the same value of polarization. The majority
of the stars in the region follow the general law of the polarization for the
interstellar medium, indicating that polarization toward the cluster Alessi 1
is dominated by foreground dust grains. The average values of the maximum
polarization ($P_{max}$) and the wavelength corresponding to the maximum
polarization ($\lambda_{max}$) toward the cluster are found to be
$0.83\pm0.03$% and $0.59\pm0.04$ $\mu$m, respectively. Also, dust grains toward
the cluster appear to be aligned, possibly due to the galactic magnetic field.
