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Discovery of extended radio emission in the young cluster Wd1
Waters, L. B. F. M.; Steele, I. A.; Fender, R. P. +4 more
We present 10-µm ISO-SWS and Australia Telescope Compact Array observations of the region in the cluster Wd1 in Ara centred on the B[e] star Ara C. An ISO-SWS spectrum reveals emission from highly ionized species in the vicinity of the star, suggesting a secondary source of excitation in the region. We find strong radio emission at both 3.5 …
The First Definitive Binary Orbit Determined with the Hubble Space Telescope Fine Guidance Sensors: Wolf 1062 (Gliese 748)
Nelan, Edmund P.; Henry, Todd J.; Kirkpatrick, J. Davy +15 more
The M dwarf binary, Wolf 1062 (Gliese 748), has been observed with the Hubble Space Telescope (HST) Fine Guidance Sensor 3 in the transfer function scan mode to determine the apparent orbit. This is the first orbit defined fully and exclusively with HST, and is the most accurate definitive orbit for any resolved, noneclipsing system. The orbital p…
Regression of Martian North Polar Cap: 1990-1997 Hubble Space Telescope Observations
Wolff, Michael J.; Cantor, Bruce A.; James, Philip B. +1 more
Hubble Space Telescope imaging of Mars from December 13, 1990, through April 17, 1997, has resulted in the synoptic monitoring of parts of four consecutive martian north polar cap regressional cycles spanningLs= 335.65° toLs= 144.56°. The 1990-1993 observations were obtained with the Wide Field Planetary Camera 1 (WFPC1) inst…
DeHoffmann-Teller Analysis
Sonnerup, Bengt U. Ö.; Khrabrov, Alexander V.
Closure of multi-fluid and kinetic equations for cyclotron-resonant interactions of solar wind ions with Alfvén waves
Marsch, E.
Based on quasilinear theory, a closure scheme for anisotropic multi-component fluid equations is developed for the wave-particle interactions of ions with electromagnetic Alfvén and ion-cyclotron waves propagating along the mean magnetic field. Acceleration and heating rates are calculated. They may be used in the multi-fluid momentum and energy e…
G Ring Particle Sizes Derived from Ring Plane Crossing Observations
Throop, Henry B.; Esposito, Larry W.
The Saturn ring plane crossings in 1995-1996 allowed observers using the Hubble Space Telescope and the W. M. Keck telescope to image the planet's diffuse rings from 0.3 to 2.2 µm at a scattering angle θ ∼ 175°. We calculate the G ring reflectance for size distributions of dust to kilometer-sized bodies derived from a physical, evolutionary …
Pulsation modes of Mira stars and questioning of linear modelling: indications from HIPPARCOS and the LMC
Barthes, D.
Thorough discussion of the previous theoretical works on the pulsation of Long Period Variables leads us to the conclusion that the mode periods predicted by linear models must significantly differ from the reality, and that, if one nevertheless relies upon such a modelling, it is at least necessary to change the mixing length. The hypothesis that…
ORFEUS II Far-Ultraviolet Observations of 3C 273: Interstellar and Intergalactic Absorption Lines
Krautter, Joachim; Bowyer, Stuart; Hurwitz, Mark +7 more
We present the first intermediate-resolution (λ/Δλ = 3000) spectrum of the bright quasi-stellar object 3C 273 at wavelengths between 900 and 1200 Å. Observations were performed with the Berkeley spectrograph aboard the ORFEUS II mission. We detect Lyβ counterparts to intergalactic Lyα features identified by Morris and coworkers at cz = 19,900, 160…
Far-infrared ISOPHOT observations and the energy balance of a quiescent globule
Lemke, D.; Lehtinen, K.; Mattila, K. +1 more
We have observed a quiescent small globule, the Thumbprint Nebula, with the ISOPHOT far-infrared camera at 100 and 200mu m. The observed emission is optically thin thermal emission from dust at a temperature of ~ 14-16K. The energy budget of the cloud is studied by considering the energy input (interstellar radiation field, ISRF), and outputs (sca…
Theoretical Oscillator Strengths for Sr II and Y III, with Application to Abundances in the HgMn-Type Star χ Lupi
Wahlgren, Glenn M.; Proffitt, Charles R.; Brage, Tomas +2 more
Oscillator strengths for selected transitions of Sr II and Y III have been determined using ab initio multiconfiguration Hartree-Fock techniques. The importance of including an accurate treatment of the core-valence correlation is emphasized. The results are used to determine the abundances of Sr and Y in the chemically peculiar star χ Lupi from H…