Search Publications
A massive hypergiant star as the progenitor of the supernova SN 2005gl
Gal-Yam, A.; Leonard, D. C.
Our understanding of the evolution of massive stars before their final explosions as supernovae is incomplete, from both an observational and a theoretical standpoint. A key missing piece in the supernova puzzle is the difficulty of identifying and studying progenitor stars. In only a single case-that of supernova SN 1987A in the Large Magellanic …
The cluster Terzan 5 as a remnant of a primordial building block of the Galactic bulge
Dalessandro, E.; Ransom, S. M.; Valenti, E. +9 more
Globular star clusters are compact and massive stellar systems old enough to have witnessed the entire history of our Galaxy, the Milky Way. Although recent results suggest that their formation may have been more complex than previously thought, they still are the best approximation to a stellar population formed over a relatively short timescale …
Two distinct sequences of blue straggler stars in the globular cluster M 30
Dalessandro, E.; Beccari, G.; Ferraro, F. R. +7 more
Stars in globular clusters are generally believed to have all formed at the same time, early in the Galaxy's history. `Blue stragglers' are stars massive enough that they should have evolved into white dwarfs long ago. Two possible mechanisms have been proposed for their formation: mass transfer between binary companions and stellar mergers result…
A high stellar velocity dispersion for a compact massive galaxy at redshift z = 2.186
van Dokkum, Pieter G.; Franx, Marijn; Kriek, Mariska
Recent studies have found that the oldest and most luminous galaxies in the early Universe are surprisingly compact, having stellar masses similar to present-day elliptical galaxies but much smaller sizes. This finding has attracted considerable attention, as it suggests that massive galaxies have grown in size by a factor of about five over the p…
A binary origin for `blue stragglers' in globular clusters
Sills, Alison; Knigge, Christian; Leigh, Nathan
Blue stragglers in globular clusters are abnormally massive stars that should have evolved off the stellar main sequence long ago. There are two known processes that can create these objects: direct stellar collisions and binary evolution. However, the relative importance of these processes has remained unclear. In particular, the total number of …
A single sub-kilometre Kuiper belt object from a stellar occultation in archival data
Zucker, S.; Gal-Yam, A.; Sari, R. +5 more
The Kuiper belt is a remnant of the primordial Solar System. Measurements of its size distribution constrain its accretion and collisional history, and the importance of material strength of Kuiper belt objects. Small, sub-kilometre-sized, Kuiper belt objects elude direct detection, but the signature of their occultations of background stars shoul…