We performed a detailed analysis of the use of [C/N] measured in red giant branch stars between the completion of the first dredge up and the red giant branch bump ([C/N] FDU) as age indicator. [C/N] FDU cannot give accurate ages for individual stars, but may provide a general chronology for the formation of composite populations and add

We present follow-up spectroscopy and photometry of 11 post-common envelope binary (PCEB) candidates identified from multiple Sloan Digital Sky Survey (SDSS) spectroscopy in an earlier paper. Radial velocity measurements using the NaIλλ8183.27, 8194.81 absorption doublet were performed for nine of these systems and provided measurements of six

Low-luminosity Active Galactic Nuclei (LLAGNs) are characterized for low-radiative efficiency, much less than one percent of their Eddington limit. Nevertheless, their main energy release may be mechanical, opposite to powerful AGN classes like Seyfert and Quasars. This work reports on the jet-driven mechanical energy and the corresponding mass

The Ariel-5 X-ray transient A1744-36 and the newly-discovered transient XTE J1748-361 may be identical (ATEL #204). Based on a 16 ks Chandra ACIS-S observation of A1744-36 made on 2003 May 28, the position of this source is RA(J2000) = 17:48:19.22, Dec(J2000) = -36:07:16.6 (uncertainty < 1").

We present a measurement of the cosmic ray (e++e-) flux in the range 0.5 GeV to 1 TeV based on the analysis of 10.6 million (e++e-) events collected by AMS. The statistics and the resolution of AMS provide a precision measurement of the flux. The flux is smooth and reveals new and distinct information. Above 30.2 GeV, the flux can be described by a

Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The