Search Publications
Low-latitude solar wind during the Fall 1998 SOHO-Ulysses quadrature
Biesecker, D. A.; Poletto, G.; Ko, Y. -K. +4 more
The Fall 1998 Solar and Heliospheric Observatory (SOHO)-Ulysses quadrature occurred when Ulysses was at 5.2 AU, 17.4°S of the equator, and off the west limb of the Sun. SOHO coronal observations, at heliocentric distances of a few solar radii, showed that the line through the solar center and Ulysses crossed, over the first days of observations, a…
Correlating Transition Region Explosive Events with Extreme-Ultraviolet Brightenings
Reeves, Katharine K.; Winebarger, Amy R.; Updike, Adria C.
Frequent small-scale reconnection events have been proposed as a possible mechanism to heat the solar corona. It has not yet been demonstrated, however, that the smallest reconnection events can heat the plasma to coronal temperatures. In this Letter, we use explosive events in the spectral line C IV λ1548 observed by the Solar Ultraviolet Measure…
Intermittent behavior in the transition region and the low corona of the quiet Sun
Vial, J. -C.; Patsourakos, S.
We present an analysis of light-curves obtained in the O IV and Ne VIII transition region and low corona lines, that were simultaneously recorded in a quiet Sun region by SUMER/SOHO. By using the flatness spectrum of the observed light-curves we searched for intermittency signatures. It was found that a significant proportion of points in the obse…
The Nondamped Nature of 12 Low-Redshift Damped Lyα Candidate Systems
Turnshek, David A.; Rao, Sandhya M.
Hubble Space Telescope (HST) UV spectroscopy of 12 candidate low-redshift damped Lyα (DLA) systems in 11 quasi-stellar objects (z=0.103 in Q0054+144, z=0.969 and z=0.987 in Q0302-223, z=0.478 in Q0454-220, z=1.476 in Q1047+550, z=1.070 in Q1206+459, z=1.228 in Q1247+267, z=0.399 in Q1318+290B, z=0.519 in Q1329+412, z=0.276 in Q1451-375, z=0.204 in…
Correlation of magnetic field intensities and solar wind speeds of events observed by ACE
Owens, Mathew J.; Cargill, Peter J.
The relationship between the magnetic field intensity and speed of solar wind events is examined using ~3 years of data from the ACE spacecraft. No preselection of coronal mass ejections (CMEs) or magnetic clouds is carried out. The correlation between the field intensity and maximum speed is shown to increase significantly when |B| > 18 nT for…
A photometric study of the two poorly known northern open clusters NGC 133 and NGC 1348
Carraro, G.
We present CCD UBVI observations obtained in the field of the previously unstudied northern open clusters NGC 133 and NGC 1348. We argue that NGC 133 is a heavily contaminated cluster, for which we identify 13 candidate members down to V=14.50 mag on the basis of the position in the two-color Diagram. Membership has been checked against proper mot…
Remote sounding of the Martian dust from ISO spectroscopy in the 2.7 µm CO 2 bands
Lellouch, E.; de Graauw, T.; Feuchtgruber, H. +2 more
This paper presents a study of Martian aerosols based on the spectral observations near 2.7 µm. Simulations by Titov et al. [Planet. Space Sci. 48 (2000) 67] showed that the depth and the shape of saturated 2.7 µm band of atmospheric CO 2 are sensitive to the presence of aerosols. This allows one to determine the aerosol opt…
Observations of the Magnetic Cataclysmic Variable VV Puppis with the Far Ultraviolet Spectroscopic Explorer
Gänsicke, B. T.; Szkody, Paula; Hoard, D. W. +5 more
We present the first far-ultraviolet (FUV) observations of the magnetic cataclysmic variable VV Puppis, obtained with the Far Ultraviolet Spectroscopic Explorer satellite. In addition, we have obtained simultaneous ground-based optical photometric observations of VV Pup during part of the FUV observation. The shapes of the FUV and optical light cu…
Thick disk and old disk carbon-rich giants in the Sun vicinity
Bergeat, J.; Knapik, A.; Rutily, B.
Making use of the HIPPARCOS data and refining a previous study of the space distribution of the carbon-rich giant stars located in the vicinity of the Sun (Paper I), we fully investigate their space distributions and space velocities on the basis of our photometric grouping (CVi i.e. carbon variable stars with i=1 to 7; HCj i.e. hot carbon stars w…
The ISO Galactic metallicity gradient revisited
Morisset, C.; Sternberg, A.; Giveon, U.
Two independent groups (Giveon et al. \cite{giveon}; Martín-Hernández et al. \cite{martin}) have recently investigated the Galactic metallicty gradient as probed by ISO observations of mid-infrared emission-lines from HII regions. We show that the different gradients inferred by the two groups are due to differing source selection and differing ex…