59 Cygni: A Tilted ϕ Persei like System

On the polarization of φ Persei

Polarimetric data of φ Per from recent observations with the HPOL spectropolarimeter and from an earlier study in the literature have been compared. It is shown that for measurements with accuracies ∆p ∼ 0.003%, temporal changes are readily detected, these seemingly being unrelated to periodic changes in scattering geometry associated with the binary nature of the star. From studies of the p(λ)...

( a ) Φ ( a , B ) Φ Φ ( B , C ) ( C , D )

53 Persei : a slowly pulsating B star ?

A new investigation of the behaviour of the star 53 Per was performed. New photometric observations allow to confirm twodominant periods p1=2.16 d, p2= 1.67 d.A third one p3= 3.64 d is detected. These long period variations are present in our radial velocities data and in old equivalent width data. The amplitude of the p1 = 2.16 d period increases from 1977 to 1991, while the amplitude of the 1...

The Optical Spectroscopic Evolution of V1974 Cygni (nova Cygni 1992)

Received ; accepted – 2 – ABSTRACT Optical observations of nova V1974 Cygni (Cygni 1992), spanning a 4 year period, have been used to study its spectroscopic evolution. The data cover a wavelength range from ∼ 3200 − 8000Å and follows the nebular evolutionary phase of the ejecta. We have modeled the integrated fluxes by means of the photoionization code CLOUDY. The models were run at a fixed ab...

φ φ φ φ φ φ k From Max - SAT to Min - UNSAT : Insights and Applications

This report describes a strong connection between maximum satisfiability and minimally-unsatisfiable subfor-mulas of any constraint system, as well as techniques for exploiting it. Focusing on CNF formulas, we explore this relationship and present novel algorithms for extracting minimally-unsatisfiable subformulas, including one that finds all such subformulas. We present experimental results s...