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Nitrogen Abundances and the Distance Moduli of the Pleiades and Hyades
King, Jeremy R.; Boesgaard, Ann M.; Chen, Yu +1 more
Recent reanalyses of HIPPARCOS parallax data confirm a previously noted discrepancy with the Pleiades distance modulus estimated from main-sequence fitting in the color-magnitude diagram. One proposed explanation of this distance modulus discrepancy is a Pleiades He abundance that is significantly larger than the Hyades value. We suggest that, bas…
Magnetic turbulence in the cusp region: 3D spectra and vortex cascades
Romanov, S. A.
Cluster satellite measurements that were carried out in the region of the altitudinal cusp in the Earth's magnetosphere and adjacent regions were processed to yield the dynamic pattern of the 3D spectra of magnetic field oscillations in the space of wave vectors, with wave numbers ranging from 0.002 to 0.5 rad/km. The anisotropic properties of spa…
Downward current electron beams observed at the dipolarization front
Fu, SuiYan; Zong, QuiGang; Pu, ZuYin +1 more
The strong field-aligned pitch angle distribution of electrons is observed right at the dipolarization front (DF) before the arriving of a high speed flow when the four Cluster satellites are traveling in the magnetotail around 15 RE on July 22, 2001. The increased electron fluxes only last for a short time period at the DF, corresponding to just …
Equatorwards Expansion of Unperturbed, High-Latitude Fast Solar Wind
Breen, A. R.; Bisi, M. M.; Fallows, R. A. +1 more
We use dual-site radio observations of interplanetary scintillation (IPS) with extremely long baselines (ELB) to examine meridional flow characteristics of the ambient fast solar wind at plane-of-sky heliocentric distances of 24 - 85 solar radii (R⊙). Our results demonstrate an equatorwards deviation of 3 - 4∘ in the bulk fas…
Light curves of six bright soft X-ray transients in M31
Nooraee, Nakisa
Disc irradiation is thought to be capable of explaining the global behaviour of the light curves of soft X-ray transients (SXTs). Depending on the strength of the central X-ray emission in irradiating the disc, the light curve may exhibit an exponential or a linear decay. The model predicts that in brighter transients a transition from exponential…
An unnamed fluvial valley system formed under different climates at Xanthe Terra, Mars
Kereszturi, Akos
Analyzing an unnamed fluvial system (at 5.2N 301.4E) in Xanthe Terra on Mars for the first time, the following chronology could be reconstructed. The first period of the fluvial erosion of the area produced channels with higher drainage density than later events, but some resurfacing after this period erased these early, probably interconnected tr…
The coronal mass ejection interaction with the induced magnetosphere of Mars due to the 27 January 2012 solar storm
Kallio, E.; Barabash, S.; Winningham, J. D. +7 more
An X-class flare on 27 January 2012 generated a high-energy particle stream advancing along the interplanetary magnetic field (IMF) which arrived at Mars in about 39 minutes, with a coronal mass ejection (CME) released from the same active region arriving at Mars several days later. The Electron Spectrometer (ELS), part of the Analyzer of Space Pl…
Clusters of galaxies in the Planck survey
Pointecouteau, E.
The Planck satellite has surveyed the whole sky more than four times. The nominal mission of two all-sky surveys will be released to the public in 2013. From the first all-sky survey, we have demonstrated the ability to detect clusters via the Sunyaev-Zel'dovich effect with high reliability and out to large redshifts. We have released the first la…
Analysis of a State Changing Supersoft X-Ray Source in M31
Nelson, T.; Patel, B.; Di Stefano, R. +3 more
We report on observations of a luminous supersoft X-ray source (SSS) in M31, r1-25, that has exhibited spectral changes to harder X-ray states. We document these spectral changes. In addition, we show that they have important implications for modeling the source. Quasisoft states in a source that has been observed as an SSS represent a newly disco…
Variation of dependence of the cusp location at different altitude on the dipole tilt
Dunlop, Malcolm; Zhang, ZiYing; Shi, JianKui +5 more
Using the Cluster cusp crossings data, dependence of the cusp location at the mid-altitude on the geomagnetic dipole tilt during northward IMF is studied. The results show that the cusp center moves 0.051° Invariant Latitude (ILAT) upon the increase of 1° in the dipole tilt angle at the average altitude of 5.8 RE (Earth radius). According to the p…