16 Result(s)

Article

The He⁺ λ 4686 line in the low chromosphere

We report an unsuccessful search for the He⁺ λ 4686 line in the low chromosphere. However, at the location of this line we detect a number of other chromospheric emission lines. This leads us to the conclusion th...

S. P. Worden, J. M. Beckers, T. Hirayama in Solar Physics (1973)

Article

Theoretical model of flares and prominences

A theoretical model of flare which explains observed quantities in Hα, EUV, soft X-ray and flare-associated solar wind is presented. It is assumed that large mass observed in the soft X-ray flare and the solar...

T. Hirayama in Solar Physics (1974)

Chapter and Conference Paper

Balloon Observation of the F-corona at the 1983 Total Solar Eclipse

A balloon observation of the F-corona in visual and infrared regions was carried out by Japanese and Indonesian teams at the total solar eclipse on June 11, 1983, in Java, Indonesia. For the visual observation...

S. Isobe, H. Tanabe, T. Hirayama, Y. Koma… in Properties and Interactions of Interplanet… (1985)

Article

Rocket observation of the EUV images of a solar flare and active regions

Images of a flare and active regions were obtained in the extreme ultraviolet emission lines such as CIII 977 Å, Ne VIII 770 Å, and HI Lβ, and hydrogen Lyman continua with a spatial resolution of less than ten se...

T. Hirayama, K. Tanaka, T. Watanabe, K. Akita, T. Sakurai, K. Nishi in Solar Physics (1985)

Chapter

Solar Activity

In preparing the present report, which covers the period July 1, 1984, to June 30, 1987, close collaboration has taken place between Commission 10 and 12, the two solar commissions, in order to avoid duplicati...

M. Pick, S. R. Kane, E. Priest, C. Alissandrakis, R. Falciani… in Reports on Astronomy (1988)

Chapter and Conference Paper

Physical conditions in prominences

As a summary of this paper I am presenting a table which is in a very similar format as I have presented in the former IAU colloquium (Hirayama, 1978), and according change was made. Though the present study d...

T. Hirayama in Dynamics of Quiescent Prominences (1990)

Chapter and Conference Paper

Magnetic morphologies of solar flares

We suggest magnetic morphologies for several flares using Hα filter-grams and a flare model of reconnection under an erupting magnetic flux rope (Hirayama, 1974). Here we select those flares which, at first si...

T. Hirayama in Flare Physics in Solar Activity Maximum 22 (1991)

Chapter and Conference Paper

Solar flare telescope and 10-cm new coronagraph

Two new telescopes were built at the National Astronomical Observatory of Japan, i.e. the Solar Flare Telescope and the 10-cm New Coronagraph. The Solar Flare Telescope was constructed at Mitaka to make observ...

K. Ichimoto, T. Sakurai, A. Yamaguchi… in Flare Physics in Solar Activity Maximum 22 (1991)

Chapter

The Soft X-ray Telescope for the SOLAR-A Mission

The Soft X-ray Telescope (SXT) of the SOLAR-A mission is designed to produce X-ray movies of flares with excellent angular and time resolution as well as full-disk X-ray images for general studies. A selection...

S. Tsuneta, L. Acton, M. Bruner, J. Lemen, W. Brown… in The Yohkoh (Solar-A) Mission (1991)

Article

The Soft X-ray Telescope for the SOLAR-A mission

The Soft X-ray Telescope (SXT) of the SOLAR-A mission is designed to produce X-ray movies of flares with excellent angular and time resolution as well as full-disk X-ray images for general studies. A selection...

S. Tsuneta, L. Acton, M. Bruner, J. Lemen, W. Brown, R. Caravalho… in Solar Physics (1991)

Article

The current sheet and Joule heating of a slender magnetic tube in the upper photosphere

Joule heating in a slender magnetic flux tube is investigated. The distribution of the magnetic field and electric sheet current encircling a vertical cylindrical magnetic tube is determined by equating the co...

T. Hirayama in Solar Physics (1992)

Chapter and Conference Paper

Photo-Stimulated Desorption of Ne Metastables from Thin Ne Layers on Solid Ar, Kr, and Xe

Photo-stimulated dcsorplion of Ne melastables(Ne*) from a thin Ne film adsorbed on solid Ar, Kr, and Xe was studied using synchrotron radiation as an excitation source. The excitation which is corresponding to...

D. E. Weibel, A. Hoshino, T. Hirayama… in Desorption Induced by Electronic Transitio… (1993)

Chapter

Coronal Heating Due to Twisting Faculae of 1 km Radii

We propose a scenario for coronal heating as a result of body Joule heating of a twisting magnetic tube of ≈10 km radius due to anomalous resistivity, whose effective collision frequency is 10^-2 times the electro...

T. Hirayama in Observational Plasma Astrophysics: Five Years of Yohkoh and Beyond (1998)

Article

Ion photodesorption from argon multilayers

G. Dujardin, L. Philippe, M. Rose, T. Hirayama, M.J. Ramage, G. Comtet… in Applied Physics A (1998)

Chapter and Conference Paper

Microstructure characterization of the YBa₂Cu₃O_7-y thin films derived from the metal-naphthenates gels coated on SrTiO₃(100) and LaAlO₃(100) substrates

The thin films of YBa₂Cu₃O_7-y, prepared by chemical solution deposition on SrTiO₃(100) and LaAlO₃(100) substrates, have been characterized by cross-sectional high-resolution electron microscopy. It is found that ...

X. L. Ma, J. Shibata, T. Hirayama, K. Yamagiwa… in Advances in Superconductivity XI (1999)

Chapter and Conference Paper

Atomic structure and dopant segregation of [0001] tilt grain boundaries in ZnO bicrystals

Physical properties of ceramics are often changed by presence of grain boundaries (GBs). One possible cause of the change is the grain boundary (GB) itself, because the GB atomic structure is different from th...

Y. Sato, T. Mizoguchi, J. P. Buban… in EMC 2008 14th European Microscopy Congress… (2008)