We present the observations of the afterglow of gamma-ray burst GRB 090102. We use optical data taken by the TAROT, REM, GROND, Palomar and NOT telescopes, and X-ray data taken by the XRT instrument on board the Swift spacecraft. This event features an unusual light curve. In X-rays, it presents a very monotonic decrease with no hint of temporal break from 0.005 to 6 days after the burst. In op...

We present photometry of the transient associated with GRB 030329 obtained with the CTIO 1.3–meter telescope and the ANDICAM instrument, a dual optical/infrared imager with a dichroic centered at one micron. Without the need for light curve interpolation to produce snapshot broadband spectra, we show that the transient spectrum remained statistically achromatic from day 2.7 to day 5.6, during a...

We present photometry of the transient associated with GRB 030329 obtained with the CTIO 1.3–meter telescope and the ANDICAM instrument, a dual optical/infrared imager with a dichroic centered at one micron. Without the need for light curve interpolation to produce snapshot broadband spectra, we show that the transient spectrum remained statistically achromatic from day 2.7 to day 5.6, during a...

We investigate the break up of the last invariant curve for analytic families of standard maps Sλ : { y′ = λg(x) + y x′ = x + y′ mod 1 , where g : S →IR is an analytic function such that ∫

The 2-m robotic Liverpool Telescope (LT) reacted promptly to the high-redshift (z = 4.048) gamma– ray burst GRB 060206. The afterglow was identified automatically and multicolor riz imaging program was triggered without human intervention. Combining our data with those obtained from later follow-ups provides a well-sampled optical light-curve from 5 minutes to >2d after the gamma event. The lig...

Given a planar spline curve and local tolerances, a matched pair of polygons is computed that encloses the curve and whose width (distance between corresponding break points) is below the tolerances. This is the simplest instance of a subdividable linear efficient variety enclosure, short sleve. We develop general criteria, that certify correctness of a global, polygonal enclosure built from a ...

The X-ray flux of the gamma-ray burst (GRB) afterglows monitored by the Swift satellite from January 2005 to July 2006 displays one to four phases of flux power-law decay. In chronological order, they are: the GRB tail, the 'hump', the standard decay and the post-jet-break decay. More than half of the GRB tails can be identified with the large-angle emission produced during the burst (but arriv...

Critical fl icker frequency (CFF) was investigated in a free swimming harp seal using behavioral techniques. The resulting CFF vs intensity curve indicates a defi nite rod/cone break, suggesting a duplex photoreceptor population, whose presence had not been observed in previous morphological reports. 1 This research was supported by a National Research Council of Canada Grant to the second auth...

The phenomenon of so-called break-away forces, as maximal actuation forces at which a sticking system begins to slide and thus passes over to a steady (macro) motion, is well known from engineering practice but still less understood in its cause-effect relationship. This note analyzes the break-away behavior of systems with nonlinear friction, which is analytically well-described by combining t...