Rings Around a Black Hole


V404 Cygni Black HoleV404 Cygni is a binary system that contains an erupting black hole. These rings of x-ray light centered on that system were imaged by the x-ray telescope aboard the Swift satellite. Color indicates the energy of the X-rays, with red representing the lowest (800 to 1,500 electron volts, eV), green for medium (1,500 to 2,500 eV), and blue for the most energetic (2,500 to 5,000 eV). Visible light has energies ranging from about 2 to 3 eV. The dark lines running diagonally through the image are artifacts of the imaging system.
Image Credits: Andrew Beardmore (Univ. of Leicester) and NASA

A Decade of Swift


The Swift satellite has been on orbit for ten years. It was the first  project I worked on at Goddard Space Flight Center. I designed and tested the ultra-low-noise power regulator assemblies that run the detector assemblies in the Burst Alert Telescope. I did the circuit design for the variable output high-voltage regulators that provide bias power to the sensors in the BAT detector assemblies. The BAT sensor array is held at a constant temperature (298 K, ± 0.5 K). I designed the pulse-width modulation regulators used in the thermal control system. The same type of PWM is used in the thermal controls for the star trackers which are a part of the satellite’s navigation system. Given that the mission design life was two years, it’s nice to see that my first bits of work are holding up.

Video Credit: NASA

A Mega Flare from a Mini Star


At 2107 UTC on  23 April, the rising tide of X-rays from a superflare on red dwarf DG CVn triggered Swift‘s Burst Alert Telescope (BAT). The satellite turned to observe the source in greater detail with its other instruments and notified astronomers around the globe that a powerful outburst was in progress.

BTW, my principal contribution to the Swift satellite was the design and testing of the ultra-quiet power regulation system for the sensor array in the BAT.

Video Credit: NASA

Too Close for Comfort


Video Credit: NASA

UPDATE—A personal note: I contributed to the design of components of the Burst Alert Telescope instrument on Swift. My contributions include the ultra-quiet power regulators for the detectors in the instrument, the variable high-voltage supply for the detectors, and the pulse-width-modulation regulator for the thermal control system of the BAT. The same PWM regulator was also used in other locations on the satellite.