Search Publications
Persistent and Self-Similar Large-Scale Density Fluctuations in the Solar Corona
Bruno, R.; Antonucci, E.; D'Amicis, R. +1 more
Density fluctuations of the low and midlatitude solar corona plasma are analyzed during the recent solar minimum period. Long time series of the intensity of the neutral hydrogen Lyα, 1216 Å, line have been observed with the UltraViolet Coronagraph Spectrometer/Solar and Heliospheric Observatory at 1.7 R sun, in low-latitude streamers a…
Hot Debris Dust Around HD 106797
Nakagawa, Takao; Onaka, Takashi; Ootsubo, Takafumi +10 more
Photometry of the A0 V main-sequence star HD 106797 with AKARI and Gemini/T-ReCS is used to detect excess emission over the expected stellar photospheric emission between 10 and 20 µm, which is best attributed to hot circumstellar debris dust surrounding the star. The temperature of the debris dust is derived as T d ~ 190 K by ass…
G 112-29 (=NLTT 18149): A Very Wide Companion to GJ 282 AB with a Common Proper Motion, Common Parallax, Common Radial Velocity, and Common Age
Costero, R.; Poveda, A.; Echevarría, J. +2 more
We have made a search for common proper motion (CPM) companions to the wide binaries in the solar vicinity. We found that the binary GJ 282AB has a very distant CPM companion (NLTT 18149) at a separation s = 1fdg09. Improved spectral types and radial velocities are obtained, and ages determined for the three components. The Hipparcos trigonometric…
Thermal Conductivity and Element Fractionation in EV Lac
Hwang, Una; Laming, J. Martin
We present a 100 ks Suzaku observation of the dMe flare star EV Lac, in which the star was captured undergoing a moderate 1500 s flare. During the flare, the count rate increased by about a factor of 50 and the spectrum showed overall enhanced element abundances relative to quiescence. While the quiescent element abundances confirm the inverse fir…
Hydrogen Lyα and Lyβ Radiances and Profiles in Polar Coronal Holes
Teriaca, Luca; Tian, Hui; Curdt, Werner +1 more
The hydrogen Lyα plays a dominant role in the radiative energy transport in the lower transition region, and is important for the studies of transition-region structure as well as solar wind origin. We investigate the Lyα profiles obtained by the Solar Ultraviolet Measurement of Emitted Radiation spectrograph on the Solar and Heliospheric Observat…
Spatial Distributions of Absorption, Local Suppression, and Emissivity Reduction of Solar Acoustic Waves in Magnetic Regions
Zhao, Hui; Liang, Zhi-Chao; Chou, Dean-Yi +2 more
Observed acoustic power in magnetic regions is lower than the quiet Sun because of absorption, emissivity reduction, and local suppression of solar acoustic waves in magnetic regions. In the previous studies, we have developed a method to measure the coefficients of absorption, emissivity reduction, and local suppression of sunspots. In this study…
How the Solar Wind Ties to its Photospheric Origins
McIntosh, Scott W.; Leamon, Robert J.
We present a new method of visualizing the solar photospheric magnetic field based on the "Magnetic Range of Influence" (MRoI). The MRoI is a simple realization of the magnetic environment in the photosphere, reflecting the distance required to balance the integrated magnetic field contained in any magnetogram pixel. It provides a new perspective …
Hubble Space Telescope NICMOS Polarization Observations of Three Edge-on Massive Young Stellar Objects
Hines, Dean C.; Colgan, Sean W. J.; Burton, Michael G. +4 more
Massive young stellar objects (YSOs), like low-mass YSOs, appear to be surrounded by optically thick envelopes and/or disks and have regions, often bipolar, that are seen in polarized scattered light at near-infrared wavelengths. We are using the 0farcs2 spatial resolution of the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) on Hubbl…
The Variable Star Population of the Globular Cluster B514 in the Andromeda Galaxy
Kinemuchi, Karen; Marconi, Marcella; Pritzl, Barton J. +8 more
A rich harvest of RR Lyrae stars has been identified for the first time in B514, a metal-poor ([Fe/H] ~- 1.95 ± 0.10 dex) globular cluster (GC) of the Andromeda galaxy (M31), based on Hubble Space Telescope Wide Field Planetary Camera 2 and Advanced Camera for Surveys time-series observations. We have detected and derived periods for 89 RR Lyrae s…
Doppler-Broadened Iron X-Ray Lines From Tycho's Supernova Remnant
Petre, Robert; Kunieda, Hideyo; Makishima, Kazuo +13 more
We use Suzaku observations to measure the spatial variation of the Fe Kα line with radius in the Tycho supernova remnant. The Fe line widths show a significant decrease from a FWHM value of 210 eV at the center to 130 eV at the rim. Over the same radial range the line center energy remains nearly constant. These observations are consistent with a …