Observations of the Crab Nebula have proven to be the best tool to calibrate and to characterize the performance of a Cherenkov telescope. Scientifically, it is interesting to measure the energy spectrum of the Crab Nebula close to the inverse-Compton peak where a deviation is expected from the power law seen at energies above 300 GeV. Additionally, it is important to search for pulsed emission...

The Advanced Compton Telescope (ACT) has been suggested to be the optimal next-generation instrument to study nuclear gammaray lines. In this work, we investigate the potential of three hypothetical designs of the ACT to perform SN science. We provide estimates of 1) the SN detection rate, 2) the SN Ia discrimination rate, and 3) which gamma-ray lines would be detected from specific supernova r...

Gamma-ray line emission is a direct probe of the nucleosynthesis that occurs in Type Ia supernovae. In this work we describe the wealth of information obtainable from observations of this emission. Advanced Compton telescope designs are being studied by the Naval Research Laboratory, with the goal being the construction of a telescope which would be capable of detecting SNe Ia to distances in e...

We report multiband observations of the Optical Transient (OT) associated with GRB000301c carried out between 2–4 March 2000 using the 2.34-m Vainu Bappu Telescope (VBT) at Kavalur, India. When combined with other reported data, the initial decline in the R-band magnitude with log (t − t0), the time since the burst is fit with a slope α1 = -0.70 ± 0.07 which steepens after about 6.0 days to a s...

Monitoring with the Ryle Telescope at 15 GHz of the Galactic X-ray transient source GRS 1915+105 has revealed a remarkable range of rapid and extended flares which appear to be related to the X-ray emission as recorded by the RXTE all-sky monitor. Quasi-periodic oscillations in the range 20 – 40 min have been found and are probably related to oscillations in the soft X-ray flux.

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— We measured the fireball Lorentz factor of GRB 060418 by the direct observation of the onset of the NIR afterglow carried with the REM telescope. We found Γ0 ∼ 400. PACS 98.70.Rz – gamma-ray bursts..

We have been using a new method to search for solar-like oscillations that involves measuring temperature changes via their effect on the equivalent widths of the Balmer hydrogen lines. We observed α Cen A over six nights in 1995 with the 3.9-metre Anglo-Australian Telescope and the European Southern Observatory's 3.6-metre telescope in Chile. Oscillations were not detected, with an upper limit...

We have been using a new method to search for solar-like oscillations that involves measuring temperature changes via their effect on the equivalent widths of the Balmer hydrogen lines. We observed α Cen A over six nights in 1995 with the 3.9-metre Anglo-Australian Telescope and the Eu-ropean Southern Observatory's 3.6-metre telescope in Chile. Oscillations were not detected, with an upper limi...

We report on the discovery of three new pulsars in the first blind survey of the north Galactic plane (45◦ < l < 135◦; |b| < 1◦) with the Giant Meterwave Radio telescope (GMRT) at an intermediate frequency of 610 MHz. The survey covered 106 square degrees with a sensitivity of roughly 1 mJy to long-period pulsars (pulsars with period longer than 1 s). The three new pulsars have periods of 318, ...