Search Publications
Rosetta target asteroid 2867 Steins: An unusual E-type asteroid
Weissman, Paul R.; Hicks, Michael D.; Choi, Young-Jun +2 more
ESA's Rosetta spacecraft will fly by main-belt asteroid 2867 Steins on September 5, 2008. We obtained new visible wavelength spectra of 2867 Steins on December 19, 2006 (UT), using the Palomar 5 m telescope and the facility Double Spectrograph. Two sets of spectra, taken ∼3 h apart, one half of the rotation period for 2867 Steins, show it to be an…
Modified gradiometer technique applied to Double Star (TC-1)
Zhang, T. L.; Takada, T.; Carr, C. M. +6 more
On TC-1 (Tan Ce 1), the equatorial spacecraft of the Double Star mission, a strong spin-synchronized magnetic interference from the solar panels was observed. In-flight correction techniques for spinning spacecraft that are based on minimizing spin tones in the spin-aligned component and in the magnitude of the ambient magnetic field are therefore…
Medium-latitude sources of plasmaspheric nonthermal continuum radiations observed close to harmonics of the electron gyrofrequency
Grimald, S.; Canu, P.; DéCréAu, P. M. E. +2 more
Nonthermal continuum (NTC) radiation is, with auroral kilometric radiation (AKR), one of the two electromagnetic emissions generated within the Earth's magnetosphere and radiated into space. It is generally believed that NTC is emitted in the plasmapause density gradient after conversion of intense electrostatic waves, present near the magnetic eq…
Formation of Transient Coronal Holes during the Eruption of a Quiescent Filament and its Overlying Sigmoid
Yang, Li-Heng; Jiang, Yun-Chun; Ren, Dong-Bai
By using Hα, He I 10830, EUV and soft X-ray (SXR) data, we examined a filament eruption that occurred on a quiet-sun region near the center of the solar disk on 2006 January 12, which disturbed a sigmoid overlying the filament channel observed by the GOES-12 SXR Imager (SXI), and led to the eruption of the sigmoid. The event was associated with a …
XMM-Newton Detection of a Compton-thick AGN in the 1 Jy ULIRG/LINER F04103-2838
Veilleux, S.; Sanders, D. B.; Young, A. J. +3 more
We report on the detection of Fe Kα emission in F04103-2838, an ultraluminous infrared galaxy [ULIRG; log (LIR/L⊙) >= 12] optically classified as a LINER. Previous Chandra observations suggested the presence of both a starburst and an active galactic nucleus (AGN) in this source. A deeper (~20 ks) XMM-Newton spectrum revea…
Near-Infrared Spectra of 21 Wolf-Rayet Stars: Wind Clumping and Mass-Loss Rates
Miyata, Takashi; Motohara, Kentaro; Nishimaki, Yuichirou +2 more
We present 0.9-2.4µm spectra of 21 galactic Wolf-Rayet (WR) stars that were obtained by using an echelle spectrograph attached to the 1.5m infrared telescope in Tokyo. The observed Wolf-Rayet stars contain 12WNE, 3WNL, and 6WC stars. The near-infrared continuum spectra can be fitted by the superposition of stellar blackbody radiation with a …
MARSIS subsurface radar investigations of the South Polar reentrant Chasma Australe
Gurnett, D. A.; Farrell, W. M.; Plaut, J. J. +12 more
The Mars Express/Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) has conducted the first-ever subsurface probing of the south polar layered deposits (SPLD) revealing internal structure that is rich in detail. We report on subsurface features detected from a set of orbits that passed over the largest of the south polar reentran…
Multi-spacecraft observations of ULF waves during the recovery phase of magnetic storm on October 30, 2003
Pu, Z. Y.; Zong, Q. G.; Xie, L. +4 more
Prominence modelling: from observed emission measures to temperature profiles
Heinzel, P.; Anzer, U.
Aims:We outline the construction of prominence - corona transition region models based upon the observations of one particular prominence.
Methods: The differential emission measure curves from observations were approximated by simple analytical functions. On this basis we constructed the temperature curve and calculated the radiative losses, …
Acoustic Radius Measurements from MDI and GONG
Hill, F.; Kholikov, S.
We study the temporal autocorrelation function (ACF) of global solar oscillations. It is well known that the "large frequency separation" is proportional to the solar acoustic radius. We analyze the ACF of MDI and GONG spherical-harmonic-coefficient time series for degrees ℓ=0−3. Acoustic radius measurements obtained from the first dominant peak l…