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Orbital elements, masses and distance of λ Scorpii A and B determined with the Sydney University Stellar Interferometer and high-resolution spectroscopy
Uytterhoeven, K.; Aerts, C.; Tuthill, P. G. +7 more
The triple system HD158926 (λSco) has been observed interferometrically with the Sydney University Stellar Interferometer, and the elements of the wide orbit have been determined. These are significantly more accurate than the previous elements found spectroscopically. The inclination of the wide orbit is consistent with the inclination previously…
Attempts to measure the magnetic field of the pulsating B star ν Eridani
Neiner, C.; Henrichs, H. F.; Schnerr, R. S. +1 more
We report on attempts to measure the magnetic field of the pulsating B star ν Eridani with the Musicos spectropolarimeter attached to the 2 m telescope at the Pic du Midi, France. This object is one of the most extensively studied stars for pulsation modes, and the existence of a magnetic field was suggested from the inequality of the frequency se…
An INTEGRAL/IBIS view of young Galactic SNRs through the 44Ti gamma-ray lines
Ballet, J.; Decourchelle, A.; Vink, J. +3 more
We present preliminary results of INTEGRAL/IBIS observations on Cas A, Tycho and Vela Junior supernova remnants in the line emission of 44Ti. This radioactive nucleus is thought to be exclusively produced in supernovae during the first stages of the explosion. It has a lifetime of about 87 yr and is then the best indicator of young SNRs…
Line profiles of water for the photon dominated region and embedded sources in the S140 region
Spaans, M.; Poelman, D. R.
H_2O is a key ingredient in many interstellar environments, like photon dominated regions and star forming clouds. It plays an important role in the oxygen chemistry and can act as a coolant in dense interstellar clouds and shocks. Observations and modelling of water lines thus provide powerful diagnostics of the physical conditions in interstella…
Carbon Monoxide in Comet 9P/Tempel 1 before and after the Deep Impact Encounter
Weaver, Harold A.; Feldman, Paul D.; A'Hearn, Michael F. +4 more
One of the goals of the Hubble Space Telescope program to observe periodic comet 9P/Tempel 1 in conjunction with NASA's Deep Impact mission was to study the generation and evolution of the gaseous coma resulting from the impact. For this purpose, the Solar Blind Channel of the Advanced Camera for Surveys was used with the F140LP filter, which is s…
Solar Energetic Particles and Radio-silent Fast Coronal Mass Ejections
Klein, K. -L.; Posner, A.; Marqué, C.
Both solar flares and shock waves driven by fast coronal mass ejections (CMEs) can accelerate charged particles in the solar corona and create transient enhancements of solar energetic particle fluxes in interplanetary space (SEP events). Fast CMEs and flares often occur together, which makes it difficult to directly identify the actual source of …
Physical Conditions in the Interstellar Medium toward HD 185418
Abel, N. P.; Ferland, G. J.; Srianand, R. +1 more
We have developed a complete model of the hydrogen molecule as part of the spectral simulation code Cloudy. Our goal is to apply this to spectra of high-redshift star-forming regions where H2 absorption is seen, but where few other details are known, to understand its implication for star formation. The microphysics of H2 is …
A Study of the Orientation of Interplanetary Magnetic Clouds and Solar Filaments
Wang, Yuming; Wang, Jingxiu; Wang, S. +2 more
As a kind of eruptive phenomenon associated with coronal mass ejections (CMEs), solar eruptive filaments are thought to be parallel to the axis of surrounding arcade coronal magnetic fields that erupt and develop into interplanetary magnetic clouds (MCs). By investigating three events from 2000 August, 2003 October, and 2003 November, we estimate …
Optical spectroscopy of X-Mega targets in the Carina nebula - VI. FO15: a new O-type double-lined eclipsing binary
Barbá, R.; Morrell, N. I.; Niemela, V. S. +3 more
We report the discovery of a new O-type double-lined spectroscopic binary with a short orbital period of 1.4 d. We find the primary component of this binary, FO15, to have an approximate spectral type O5.5Vz, i.e. a zero-age main-sequence (ZAMS) star. The secondary appears to be of spectral type O9.5V. We have performed a numerical model fit to th…
The first detection of propane on Saturn
Bézard, Bruno; Moses, Julianne I.; Lacy, John H. +3 more
We report the first detection of propane, C 3H 8, in Saturn's stratosphere. Observations taken on September 8, 2002 UT at NASA's IRTF using TEXES, show multiple emission lines due to the 748 cm -1ν band of C 3H 8. Using a line-by-line radiative transfer code, we are able to fit the data by sca…