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On the basis of the near infrared observations of bulge red clump stars near the Galactic center, we have determined the galactocentric distance to be R 0 = 7.52 ± 0.10 (stat) ±0.35 (sys) kpc. We observed the red clump stars at | l | 1. • 0 and 0. • 7 | b | 1. • 0 with the IRSF 1.4 m telescope and the SIRIUS camera in the H and K S bands. After extinction(More)
Studies of the structure and evolution of protoplanetary disks are important for understanding star and planet formation. Here we present the direct image of an interacting binary protoplanetary system. Both circumprimary and circumsecondary disks are resolved in the near-infrared. There is a bridge of infrared emission connecting the two disks and a long(More)
We have determined the ratios of total to selective extinction in the near-infrared bands (J, H, K S) toward the Galactic center from the observations of the region | l | 2. • 0 and 0. • 5 | b | 1. • 0 with the IRSF telescope and the SIRIUS camera. Using the positions of red clump stars in color-magnitude diagrams as a tracer of the extinction and(More)
We determine and compare the color excess ratios E J ÀH /E HÀK S for the Ophiuchi and Chamaeleon dark clouds with the J-, Hand nd K s-band simultaneous camera, SIRIUS, on the IRSF 1.4 m telescope at SAAO. Determining accurate ratios is indispensable for discussions of the extinction law. However, previous surveys suffered from uncertainties in transforming(More)
– 2 – On the basis of near-infrared imaging observations, we derived visual extinction (A V) distribution toward ten Bok globules through measurements of both the color excess (E H−K) and the stellar density at J, H, and K s (star count). Radial column density profiles for each globule were analyzed with the Bonnor-Ebert sphere model. Using the data of our(More)
The Earth's ionosphere is one of the important area for shortwave telecommunications and broadcasting. The conditions of the ionosphere varies depending on activities of space weather. Arctic and Antarctic regions are the gateway of electromagnetic and mechanical energy transfer between the magnetosphere and the ionosphere. National Institute of Information(More)
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