Search Publications
Local Fractional Frequency Shifts Used as Tracers of Magnetic Activity
Toomre, Juri; Hindman, Bradley; Haber, Deborah +1 more
Using data from SOI-MDI (Haber et al., 2000), we compute the local frequencies of high-degree p modes and f modes. The frequencies are obtained through ring-diagram mode fitting. The Dense-Pack data set consists of a mosaic of 189 overlapping tiles, each tracked separately at the surface rotation rate over 1664-min time intervals during the Dynami…
Lithium and rotation on the subgiant branch. II. Theoretical analysis of observations
de Laverny, P.; De Medeiros, J. R.; Charbonnel, C. +2 more
Lithium abundances and rotation, determined for 120 subgiant stars in Lèbre et al. (1999) are analyzed. To this purpose, the evolutionary status of the sample as well as the individual masses have been determined using the HIPPARCOS trigonometric parallax measurements to locate very precisely our sample stars in the HR diagram. We look at the dist…
Laboratory investigation on the formation of unsaturated nitriles in Titan's atmosphere
Kaiser, R. I.; Balucani, N.; Asvany, O. +3 more
Crossed molecular beam experiments of ground state cyano radicals, CN(X 2Σ +), with hydrocarbons acetylene (C 2H 2), ethylene (C 2H 4), methylacetylene (CH 3CCH), allene (H 2CCCH 2), dimethylacetylene (CH 3CCCH 3), and benzene (…
Local Luminosity Function at 15 Microns and Galaxy Evolution Seen by ISOCAM 15 Micron Surveys
Xu, Cong
A local luminosity function at 15 µm is derived using the bivariate (15 µm vs. 60 µm luminosity) method, based on the newly published ISOCAM LW3 band (15 µm) survey of the very deep IRAS 60 µm sample in the north ecliptic pole region (NEPR). New IRAS 60 µm fluxes are obtained using the SCANPI/SUPERSCANPI softwar…
A moving group of young stars in Carina-Vela
Makarov, Valeri V.; Urban, Sean
Accurate two-colour photometry and proper motions of 7096 young X-ray stars in the ROSAT All-Sky Survey Bright Star Catalogue, version 1RXS, are extracted from the Tycho-2 Catalogue. The sample is dominated by red main-sequence and possibly pre-main-sequence stars. On a global proper motion convergence map, two features are very prominent: the nea…
A numerical study of the evolution of the solar wind from Ulysses to Voyager 2
Wang, C.; Richardson, J. D.; Gosling, J. T.
Voyager 2 continues to explore the outer heliosphere as Ulysses studies the latitudinal dependence of the solar wind. During the year 1991 these spacecraft were within 2° latitude and their radial separation was larger than 30 AU. This alignment presents a good opportunity to investigate the evolution of the solar wind and, in particular, the effe…
ROSAT HRI catalogue of X-ray sources in the LMC region
Pietsch, W.; Haberl, F.; Sasaki, M.
All 543 pointed observations of the ROSAT High Resolution Imager (HRI) with exposure times higher than 50 s and performed between 1990 and 1998 in a field of 10°\ x 10°\ covering the Large Magellanic Cloud (LMC) were analyzed. A catalogue was produced containing 397 X-ray sources with their properties measured by the HRI. The list was cross-correl…
The Evolving Morphology of the Bipolar Nebula M2-9
Corradi, R. L. M.; Balick, Bruce; Schwarz, H. E. +1 more
The planetary nebula M2-9 has drastically changed its shape since its discovery by Minkwoski. Although the outline of the nebula seems to be stationary, most of the knots and bright features (N1, N2, S1, and S2) have moved laterally from the west to the east edges of both lobes. These features and their changes have reflection, not point, symmetry…
Hydrogen Lyα Absorption Predictions by Boltzmann Models of the Heliosphere
Zank, Gary P.; Wood, Brian E.; Müller, Hans-Reinhard
We use self-consistent kinetic/hydrodynamic models of the heliosphere to predict H I Lyα absorption profiles for various lines of sight through the heliosphere. These results are compared with Lyα absorption lines of six nearby stars observed by the Hubble Space Telescope. The directions of these lines of sight range from nearly upwind (36 Oph) to…
The Mass Function of Main-Sequence Stars in NGC 6397 from Near-Infrared and Optical High-Resolution Hubble Space Telescope Observations
Paresce, Francesco; De Marchi, Guido; Pulone, Luigi
We have investigated the properties of the stellar mass function in the globular cluster NGC 6397 through the use of a large set of Hubble Space Telescope (HST) observations. The latter include existing WFPC 2 images in the V and I bands, obtained at ~4.5‧ and 10' radial distances, as well as a series of deep images in the J and H bands obtained w…