The Hiroshima Astrophysical Science Center (HASC) was founded in 2004 at Hiroshima University, Japan. The main mission of this institute is the observational study of various transient objects includ- ing gamma-ray bursts, supernovae, novae, cataclysmic variables, and active galactic nuclei by means of multi-wavelength observations. HASC consists of three divisions; the optical-infrared astronomy divi- sion, high-energy astronomy division, and theoretical astronomy division. HASC is operating the 1.5m optical-infrared telescope Kanata, which is dedicated to follow-up and monitoring observations of transient objects. The high-energy division is the key operation center for the Fermi gamma-ray space telescope. HASC and the high-energy astronomy group in the department of physical science at Hiroshima University are closely collaborating with each other to promote multi-wavelength time-domain astronomy. We report the recent activities of HASC and some science topics pursued by this multi-wavelength collaboration.

ABSTRACT
1. INTRODUCTION
2. JET SOURCES AND POLARIMETRIC OBSERVA-TIONS
3. SIMULTANEOUS MULTI-BAND OBSERVATIONS
4. SUMMARY
REFERENCES

• Makoto Uemura(Hiroshima Astrophysical Science Center, Hiroshima University)
• Michitoshi Yoshida(Hiroshima Astrophysical Science Center, Hiroshima University)
• Koji, S. Kawabata(Hiroshima Astrophysical Science Center, Hiroshima University)
• Tsunefumi Mizuno(Hiroshima Astrophysical Science Center, Hiroshima University)
• Yasuyuki, T. Tanaka(Hiroshima Astrophysical Science Center, Hiroshima University)
• Hiroshi Akitaya(Hiroshima Astrophysical Science Center, Hiroshima University)
• Yousuke Utsumi(Hiroshima Astrophysical Science Center, Hiroshima University)
• Yuki Moritani(Hiroshima Astrophysical Science Center, Hiroshima University)
• Ryosuke Itoh(Department of Physical Sciences, Hiroshima University)
• Yasushi Fukazawa(Department of Physical Sciences, Hiroshima University)
• Hiromitsu Takahashi(Department of Physical Sciences, Hiroshima University)
• Masanori Ohno(Department of Physical Sciences, Hiroshima University)
• Takahiro Ui(Department of Physical Sciences, Hiroshima University)
• Katsutoshi Takaki(Department of Physical Sciences, Hiroshima University)
• Nana Ebisuda(Department of Physical Sciences, Hiroshima University)
• Kenji Kawaguchi(Department of Physical Sciences, Hiroshima University)
• Kensyo Mori(Department of Physical Sciences, Hiroshima University)
• Yuma Ohashi(Department of Physical Sciences, Hiroshima University)
• Yuka Kanda(Department of Physical Sciences, Hiroshima University)
• Miho Kawabata(Department of Physical Sciences, Hiroshima University)
• Koji Takata(Department of Physical Sciences, Hiroshima University)
• Tatsuya Nakaoka(Department of Physical Sciences, Hiroshima University)