A high-mass X-ray binary descended from an ultra-stripped supernova.

Ultra-stripped supernovae are different from other terminal explosions of massive stars, as they show little or no ejecta from the actual supernova event. They are thought to occur in massive binary systems after the exploding star has lost its surface through interactions with its companion. Such supernovae produce little to no kick, leading to the formation of a neutron star without loss of the binary companion, which itself may also evolve into another neutron star.

Detection of the Progenitors of Be X-ray Binaries.

A recent survey of the far-ultraviolet spectra of 264 B-emission line stars has revealed 16 systems with hot companions that are the stripped down remains of a former mass donor star. Some of these will probably become Be + neutron star X-ray binaries in the future. The actual numbers of such systems may be large, because the detected systems have companions that occupy the brief and bright, He-shell burning stage of evolution.

High Mass X-ray Binaries: Beacons in a Stormy Universe.

The discovery of gravity waves from the mergers of black hole binaries has focused the astronomical community on the high mass X-ray binaries (HMXBs) as the potential progenitors of close pairs of compact stars. This symposium gathered experts in observational and theoretical work for a very timely review of our understanding of the processes that drive the X-ray luminosity of the diverse kinds of binaries and what evolutionary stages are revealed in the observed cases. Here I offer a condensed summary of some of the results about massive star properties, the observational categories of HMXBs, their accretion processes, their numbers in the Milky Way and other galaxies, and how they may be related to the compact binaries that merge in a burst of gravity waves.

The expanding fireball of Nova Delphini 2013.

A classical nova occurs when material accreting onto the surface of a white dwarf in a close binary system ignites in a thermonuclear runaway. Complex structures observed in the ejecta at late stages could result from interactions with the companion during the common-envelope phase. Alternatively, the explosion could be intrinsically bipolar, resulting from a localized ignition on the surface of the white dwarf or as a consequence of rotational distortion.

Trends in intake and outcome data for animal shelters in a large U.S. Metropolitan area, 1989 to 2010.

Trends in nonhuman animal shelter intake and outcomes for dogs and cats in Metro Denver, CO, between 1989 and 2010 were assessed by linear regression analyses of data from 4 of the largest facilities covering 3 counties. The data were analyzed for trends on 3 scales: actual numbers per year, number per 1,000 residents per year, and as a percentage of total intake. Approximately 21,000 dogs and 16,000 cats were taken into the shelters in 2010, representing a 24% decrease for each since 1989.