Science Archives Publication System

Hot Cores in Coronal Filament Cavities

DOI: 10.1016/S0273-1177(99)00618-3 Bibcode: 2000AdSpR..25.1859H

Schwenn, R.; Hudson, H.

Filaments represent cold intrusions in the corona, embedded in magnetic configurations termed ``filament cavities.'' Such cavities may occur without actually containing prominence material. A cavity then may erupt, leading to a coronal mass ejection (CME). Studies of Yohkoh soft X-ray images have previously shown that such eruptions may contain el…

2000 • Advances in Space Research

SOHO 22

Another Search for Maia Variable Stars

DOI: 10.1086/316577 Bibcode: 2000PASP..112..846P

Percy, John R.; Wilson, Joseph B.

We have used the Hipparcos epoch photometry database, and autocorrelation analysis, to search for the elusive Maia variables-short-period B7-A3 near-main-sequence pulsating variable stars. Of several hundred stars considered, and several dozen stars studied in detail, only a handful are possible variables: three are possible shallow eclipsing vari…

2000 • Publications of the Astronomical Society of the Pacific

Hipparcos 21

Helmet Streamers with Triple Structures: Simulations of resistive dynamics

DOI: 10.1023/A:1005226213819 Bibcode: 2000SoPh..191..391W

Wiegelmann, Thomas; Schindler, Karl; Neukirch, Thomas

Recent observations of the solar corona with the LASCO coronagraph on board of the SOHO spacecraft have revealed the occurrence of triple helmet streamers even during solar minimum, which occasionally go unstable and give rise to large coronal mass ejections. There are also indications that the slow solar wind is either a combination of a quasi-st…

2000 • Solar Physics

SOHO 21

Optical Identification of Faint X-Ray Sources in the Core of ω Centauri

DOI: 10.1086/308582 Bibcode: 2000ApJ...532..461C

Cool, Adrienne M.; Grindlay, Jonathan E.; Carson, Jennifer E.

We present the results of a search for optical counterparts of three faint X-ray sources in the core of NGC 5139 (ω Cen) with the HST Wide Field Planetary Camera 2. Using images taken through the F656N (Hα), F675W, and F336W filters, we have identified two stars with strong Hα and UV excesses, one in each of two of the X-ray error circles, and a p…

2000 • The Astrophysical Journal

eHST 21

DENIS and ISOGAL properties of variable star candidates in the Galactic Bulge

Bibcode: 2000A&A...362..215S

Alard, C.; Blommaert, J. A. D. L.; Ganesh, S. +9 more

Repeated DENIS observations (summer 1996 & 1998) in the J (1.25 mu m) and the K_S (2.15 mu m) bands are used to look for variable stars. We present two catalogues of ~ 1000 probable variables in an area of ~ 4 deg² of the inner galactic bulge. The first one contains ~ 720 variable star candidates which show variability in …

2000 • Astronomy and Astrophysics

ISO 21

Optimizing ISOCAM data processing using spatial redundancy

DOI: 10.1051/aas:2000285 Bibcode: 2000A&AS..146..519M

Miville-Deschênes, M. -A.; Boulanger, F.; Abergel, A. +1 more

Several instrumental effects of the Long Wavelength channel of ISOCAM, the camera on board the Infrared Space Observatory, degrade the processed images. We present new data-processing techniques that correct these defects, taking advantage of the fact that a position in the sky has been observed by several pixels at different times. We use this re…

2000 • Astronomy and Astrophysics Supplement Series

ISO 21

The age of globular clusters

DOI: 10.1016/S0370-1573(00)00014-4 Bibcode: 2000PhR...333...33K

Krauss, L. M.

I review here recent developments which have affected our understanding of both the absolute age of globular clusters and the uncertainties in this age estimate, and comment on the implications for cosmological models. This present estimate is in agreement with the range long advocated by David Schramm. The major uncertainty in determining ages of…

2000 • Physics Reports

Hipparcos 21

V1334 Cygni: A Triple System Containing a Classical Cepheid

DOI: 10.1086/301397 Bibcode: 2000AJ....119.3050E

Evans, Nancy Remage

We have observed the small-amplitude Cepheid V1334 Cyg A (pulsation period 3.3 days) for nearly 30 years. From these radial velocity data we have derived an orbit with a period of 5 years. From this orbit we have derived limits on the mass of the companion (V1334 Cyg C) of 3.1 to 4.4 M_solar. The system is also a marginally resolved visu…

2000 • The Astronomical Journal

IUE 21

An Empirical Test of the Mg II λ1240 Doublet Branching Ratio and Oscillator Strength

DOI: 10.1086/308455 Bibcode: 2000ApJ...531..384S

Sofia, Ulysses J.; Howk, J. Christopher; Fabian, Dirk

We empirically confirm the theoretical branching ratio and oscillator strength for the weak Mg II 3s-4p doublet at 1240 Å as determined by Theodosiou & Federman. We use the independent methods of apparent optical depth analysis for the sight lines toward µ Col, γ Ara, and ρ Leo and profile component fitting for the sight line toward &mic…

2000 • The Astrophysical Journal

eHST 21

Far infrared spectroscopy of FU Ori objects. ISO-LWS observations

Bibcode: 2000A&A...357.1035L

Liseau, R.; White, G. J.; Benedettini, M. +12 more

We present the results of the first spectrophotometric observations of a sample of FU Ori objects obtained with the Long Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). The [OI] (63 mu m) and the [CII] (158 mu m) lines are commonly observed in all spectra (both ON and OFF source). The observational novelty is the prese…

2000 • Astronomy and Astrophysics

ISO 21