Search Publications
High resolution optical spectroscopy of IRAS 09425-6040 (=GLMP 260)
García-Lario, P.; García-Hernández, D. A.; Abia, C. +1 more
We present high resolution optical spectroscopic observations of IRAS 09425-6040, a peculiar, extremely red, C-rich AGB star showing prominent O-rich dust features in its ISO infrared spectrum attributed to crystalline silicates. Our analysis shows that IRAS 09425-6040 is indeed a C-rich star slightly enriched in lithium ({log (Li/H) + 12} ∼ 0.7) …
A Cluster of Galaxies Hiding behind M31: XMM-Newton Observations of RX J0046.4+4204
Trudolyubov, Sergey; Kotov, Oleg; Vestrand, W. Thomas
We report on our serendipitous discovery with the XMM-Newton Observatory of a luminous X-ray-emitting cluster of galaxies that is located behind the Andromeda galaxy (M31). X-ray emission from the cluster was detected previously by ROSAT and cataloged as RX J0046.4+4204, but it was not recognized as a galaxy cluster. The much greater sensitivity o…
Hubble Space Telescope observations of SV Cam - II. First derivative light-curve modelling using PHOENIX and ATLAS model atmospheres
Jeffers, S. V.; Collier Cameron, A.; Hussain, G. A. J. +2 more
The variation of the specific intensity across the stellar disc is an essential input parameter in surface brightness reconstruction techniques such as Doppler imaging, where the relative intensity contributions of different surface elements are important in detecting star-spots. We use PHOENIX and ATLAS model atmospheres to model light curves der…
Probing plasma properties and dynamics inside the Sun
Kosovichev, Alexander G.
Helioseismology experiment MDI on board the SOHO spacecraft has provided tremendous amount of new information about the thermodynamic properties and dynamics of plasma in the Sun’s interior, uncovering remarkable new perspectives for studying complex interactions between turbulent convection, rotation and magnetism below the solar surface, and the…
Ceres: High-resolution imaging with HST and the determination of physical properties
Russell, C. T.; Stern, S. A.; Young, E. F. +4 more
Nine HST orbits have been used to image Ceres using the High Resolution Camera of the Advanced Camera for Surveys. Two hundred and fifty-nine images in three filters (F555W, F330W and F220W) were obtained covering the entire surface. Two visible features are readily apparent, a dark patch and a bright point. The bright spot was suitable for contro…
A new luminous supersoft X-ray source in NGC 300
Schirmer, M.; Wilms, J.; Kendziorra, E. +1 more
Context: .We report the discovery of a new luminous supersoft source,
The Remarkable Far-Ultraviolet Spectrum of FK Comae Berenices: King of Spin
Ayres, Thomas R.; Redfield, Seth; Harper, Graham M. +4 more
A Far Ultraviolet Spectroscopic Explorer (FUSE) pointing on the ultrafast rotating yellow giant FK Comae Berenices (HD 117555; vsini~163 km s-1) recorded emission profiles of C III λ977 (T~8×104 K) and O VI λ1031 (T~3×105 K) that are exceptionally broad and asymmetric, but nearly identical in shape, aside from a bl…
Inference of magnetospheric currents from multipoint magnetic field measurements
Van Allen, James A.
The European Space Agency has deployed four essentially identical spacecraft into similar near-polar eccentric orbits about the Earth. Each of the four spacecraft carries dual three-axis magnetometers. From simultaneous observations of the magnetic field B at the four vertices of the tetrahedral cluster of spacecraft, it is possible to determine ∇…
Identification of the broad solar emission features near 117 nm
Kurucz, R. L.; Avrett, E. H.; Loeser, R.
Wilhelm et al. have recently called attention to the unidentified broad emission features near 117 nm in the solar spectrum. They discuss the observed properties of these features in detail but do not identify the source of this emission. We show that the broad autoionizing transitions of neutral sulfur are responsible for these emission features.…
VI Photometry of Globular Clusters NGC 6293 and NGC 6541: The Formation of the Metal-poor Inner Halo Globular Clusters
Lee, Jae-Woo; Carney, Bruce W.
We present VI photometry of the metal-poor inner halo globular clusters NGC 6293 and NGC 6541 using the WFPC2 on board the Hubble Space Telescope (HST). Our color-magnitude diagrams of the clusters show well-defined blue horizontal-branch populations, consistent with their low metallicities and old ages. NGC 6293 appears to have blue straggler sta…