H. S. Das

Polarimetric studies of Comet C/2009 P1 (Garradd)

We present the optical imaging polarimetric observations of comet C/2009 P1 (Garradd) at three different phase angles e.g. 28

Aggregate dust model to study the polarization properties of comet C/1996 B2 Hyakutake

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Study of background star polarization and polarization efficiency of three selected Bok globules: CB56, CB60 and CB69

2, 28

Study of grain alignment efficiency and a distance estimate for small globule CB4

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Distance estimation of some selected small Bok globules

1 and 21

JaSTA-2: Second version of the Java Superposition T-matrix Application

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Study of light scattering properties of dust aggregates with a wide variation of porosity

6. The observations were carried out using the Inter University Centre for Astronomy and Astrophysics (IUCAA) Faint Object Spectrograph and Camera mounted on Cassegrain focus of the 2 m telescope of IGO, IUCAA, Pune, in R comet , Rphotometric bands, on 2012 March 21 and 22 and Aryabhatta Research Institute of observational sciencES (ARIES) Imaging Polarimeter mounted on Cassegrain focus of the 1.04 m Sampurnanand Telescope of ARIES, Nainital, in R photometric band, on 2012 May 23. We show the presence of a jet activity in the rotational-gradient-treated image of comet Garradd at phase angle 28

Study of magnetic field geometry and extinction in Bok globule CB130

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Correlation among extinction efficiency and other parameters in an aggregate dust model

1. These jets are mainly oriented towards the Sun and extended up to ∼5100 km from the cometary photocentre. The antisolar extension of the jet seems to be fainter, which is extended up to ∼1800 km. It is found that the comet Garradd shows negative polarization at phase angle 21

Imaging polarimetry of comets C/2013 V1 (Boattini) and 290P/Jager before and after perihelion

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