  We present the results from a multiwavelength study of the flaring activity
in HBL, 1ES 1959+650, during January 2015-June 2016. The source underwent
significant flux enhancements showing two major outbursts (March 2015 and
October 2015) in optical, UV, X-rays and gamma-rays. Normally, HBLs are not
very active but 1ES 1959+650 has shown exceptional outburst activity across the
whole electromagnetic spectrum (EMS). We used the data from Fermi-LAT,
Swift-XRT & UVOT and optical data from Mt. Abu InfraRed Observatory (MIRO)
along with archival data from Steward Observatory to look for possible
connections between emissions at different energies and the nature of
variability during flaring state. During October 2015 outburst, thirteen nights
of optical follow-up observations showed brightest and the faintest nightly
averaged V-band magnitudes as 14.45(0.03) and 14.85(0.02), respectively. In
optical, the source showed a hint of optical intra-night variability during the
outburst. A significant short-term variability in optical during MJD 57344 to
MJD 57365 and in gamma-rays during MJD 57360 and MJD 57365 was also noticed.
Multiwavelength study suggests the flaring activity at all frequencies to be
correlated in general, albeit with diverse flare durations. We estimated the
strength of the magnetic field as 4.21 G using the time-lag between optical and
UV bands as synchrotron cooling time scale (2.34 hrs). The upper limits on the
sizes of both the emission regions, gamma-ray and optical, are estimated to be
of the order of 10^16cm using shortest variability time scales. The
quasi-simultaneous flux enhancements in 15 GHz and VHE gamma-ray emissions
indicates to a fresh injection of plasma into the jet, which interacts with a
standing sub-mm core resulting in co-spatial emissions across the EMS. The
complex and prolonged behavior of the second outburst in October 2015 is
discussed in detail.
