Kwasan and Hida Observatories, Graduate School of Schience, Kyoto University Japanese Home page

Contributions & Recent Works

Contribution list (1949--2017)

PhD Thesis Authors and Titles (since 1995)

Superflares on solar-type stars
The research group at Kwasan observatory, using data from the Kepler satellite, discovered more than 360 examples of superflares (flares that are 100 to 1000 times larger than the biggest solar flare) on solar-type stars. This research was published on the 17th May 2012 in the scientific journal Nature.

Recent Solar Activity
Between 2008 and 2009, the number of sunspots observed on the solar surface was at its lowest for 100 years, but recently there has been a sudden surge in solar activity and the current cycle (cycle 24) is producing large flares (huge releases of energy in the solar atmosphere). At Hida Observatory, solar flare monitoring observations have been taking place and on 9th August 2011 and 7th and 8th September 2011 (JST) large flares could be observed.

If you plan to use any of the movies or images, first read the Observatory webpage data policy.

The Discovery of Convection in Solar Prominences
A research group including Professor Kazunari Shibata and Andrew Hillier (Graduate Student) of Kwasan Observatory discovered that convection is occurring in solar prominences. The results from this research were published in the leading scientific journal "Nature".

Evolution of the anemone AR NOAA 10798 and the related geo-effective flares and CMEs
We examine in detail the evolution of an anemone active region (AR) that emerged in a Coronal Hole and the related flares, CMEs, and the geomagnetic storm to elucidate how such a magnetic configuration works to generate a geo-effective flares/CMEs. We found that the fast CMEs are probably a consequence of the eruption inside a Coronal Hole from an sea anemone AR, and discuss the importance of ARs that show the anemone structure for the space weather studies.

Asai, A. et al. (2009)
The Journal of Geophysical Research, 114, A00A21, doi:10.1029/2008JA013291.  

Abstract / Article on web(JGR web-page)

Three Successive and Interacting Shock Waves Generated by a Solar Flare
We discovered three successive Moreton waves generated by a single solar flare. These waves were observed on 3 August 2005 with Solar Magnetic Activity Research Telescope (SMART) at Hida Observatory of Kyoto University.

Narukage, N. et al.
The Astrophysical Journal Letters, 684: L45--L49 (2008) 

Abstract / Movies
Full article on web(ApJL web-page)

about SMART / SMART Data Archive

Papers about HINODE observations

(1) Chromospheric Anemone Jets as Evidence of Ubiquitous Reconnection
Shibata, K. et al.
Science vol.318, No.5856, pp1591--1594 (2007)   Abstract

Ca II H jet
The Ca II H broadband filter snapshot image of the active region on 17 December 2006 near the west limb, taken with Hinode/SOT. Numerous tiny jets ejected from bright points (arrows) can be seen.

Link to Science web-page   Full article on web / PDF file

(2) Umbral Fine Structures in Sunspots Observed with Hinode Solar Optical Telescope
Kitai, R. et al.
Publ. Astron. Soc. Japan vol.59, No.SP3, ppS585--S591 (2007)

(3) Small-Scale Magnetic-Flux Emergence Observed with Hinode Solar Optical Telescope
Otsuji, K. et al.
Publ. Astron. Soc. Japan vol.59, No.SP3, ppS649--S654 (2007)

Link to PASJ web-page   Title list / Kitai et al. / Otsuji et al.