ar X iv : a st ro - p h / 99 05 37 8 v 1 2 8 M ay 1 99 9 New evolutionary scenarios for short orbital period CVs

ar X iv : a st ro - p h / 99 05 37 6 v 1 2 8 M ay 1 99 9 A 6 . 4 - hr positive superhump period in TV

ar X iv : a st ro - p h / 92 05 00 5 v 1 9 M ay 1 99 2 UCSBTH – 92 – 05 April 1992 CHAOTIC DARK MATTER

A very weakly coupled scalar field with mass m and initial vacuum expectation value V will provide enough mass to close the universe provided V ≃ (3 × 10 8 GeV)(100 GeV/m) 1/4. We discuss possible models in which such a field could arise. (a) Electronic address (internet): [email protected].

ar X iv : a st ro - p h / 98 05 20 5 v 1 1 5 M ay 1 99 8 The double - lined spectroscopic binary α Andromedae : orbital elements and elemental abundances

We performed a spectroscopic study of the SB2 Mercury-Manganese star α And. Our measurements of the secondary’s radial velocities result in improved orbital elements. The secondary shows abundances typical of the metallic-line stars: a Ca deficiency, small overabundances of the iron-peak elements, and 1.0 dex overabundances of Sr and Ba.

ar X iv : a st ro - p h / 97 05 13 8 v 1 1 9 M ay 1 99 7 Periodic Orbits in Triaxial Galaxies with Weak Cusps

The orbital structure of triaxial models with weak central density cusps, ρ ∝ r −γ , γ < 1, is investigated. The stability of the x-(long-) axis orbit – and hence the existence of box orbits – depends sensitively on γ; the range of model shapes for which the x-axis orbit is stable becomes progressively smaller as γ approaches one. The banana and fish boxlets in the x − z (long axis–short axis) ...

ar X iv : a st ro - p h / 98 05 07 7 v 1 6 M ay 1 99 8 Long - Term X - ray Variability in GX 354 – 0

We report for the first time the detection of long-term X-ray variability in the bright bulge source GX 354–0 (=4U 1728–34) observed with the All Sky Monitor (ASM) on board the Rossi X-Ray Timing Explorer (RXTE). The 2-year RXTE ASM database reveals significant power at ∼ 72 days. Similar behaviour was seen in the 6-year Ariel 5 ASM database, but at a period of ∼ 63 days. The timescales and lig...