54 citations · 242 across the 12 of their papers we have counts for
6 papers · 1 filter
Is a binary fraction-age relation responsible for the lack of EHB binaries in globular clusters?
C. Moni Bidin, M. Catelan, M. Altmann
The recently-discovered lack of close binaries, among extreme horizontal branch (EHB) stars in Galactic globular clusters, has thus far constituted a major puzzle, in view of the f…
A Search for EHB Pulsators in the Globular Cluster NGC 6752
M. Catelan, G. E. Prieto, M. Zoccali +8
We describe the status of a project whose main goal is to detect variability along the extreme horizontal branch of the globular cluster NGC 6752. Based on Magellan 6.5m data, prel…
Searching for merger debris in the Galactic halo: Chemodynamical evidence based on local blue HB stars
Martin Altmann, Marcio Catelan, Manuela Zoccali
We report on the discovery of a group of local A-type blue horizontal-branch (HBA) stars moving in a prograde, comet-like orbit with very similar kinematics and abundances. This se…
High resolution spectroscopy of bright subdwarf B stars - I. Radial velocity variables
H. Edelmann, U. Heber, M. Altmann +2
Radial velocity curves for 15 bright subdwarf B binary systems have been measured using high precision radial velocity measurements from high S/N optical high-resolution spectra. I…
Kinematics of RHB stars to trace the structure of the galaxy
T. A. Kaempf, K. S. de Boer, M. Altmann
Red horizontal-branch (RHB) stars have been selected from the HIPPARCOS catalogue to investigate their kinematics and spatial distribution. HIPPARCOS parallaxes, literature radial…
The mass of the sdB primary of the binary HS 2333+3927
U. Heber, H. Drechsel, C. Karl +8
Short period sdB binaries with cool companions are crucial to understand pre-CV evolution, because they will evolve into cataclysmic variables, when the sdB will have left the exte…