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.

Gamma Ray Burst


When a massive star collapses to form a black hole, a burst of gamma rays results as particles are blasted outward at nearly the speed of light. This animation shows the most common type of gamma-ray burst. An end-on view of a jet greatly boosts its apparent brightness. One especially bright burst (GRB 130427A) was detected in 2013 by the Fermi and Swift satellites. A Fermi image of that burst ends the animation sequence.

Video Credit: NASA

Detecting a Supernova


Beforem82_uvot_before_sn_largeAfterm82_uvot_after_sn_large-arrow_0These Swift Ultraviolet optical telescope images show a galaxy called M82 before and after the new supernova. The pre-explosion view combines data taken between 2007 and 2013. The view showing SN 2014J (arrow) merges three exposures taken on 22 January, 2014. Mid-ultraviolet light is shown in blue, near-UV light in green, and visible light in red. The image is slightly more than half the apparent diameter of a full moon across.

This is a Type Ia supernova, the total destruction of a white dwarf star by one of two possible scenarios. In one, the white dwarf orbits a normal star, pulls a stream of matter from it, and gains mass until it reaches a critical threshold and explodes. In the other, the blast arises when two white dwarfs in a binary system eventually spiral inward and collide.

In either case, the explosion produces a superheated shell of plasma that expands outward into space at tens of millions of miles an hour. The interactions between the shell’s size, transparency and radioactive heating control when the supernova reaches peak brightness. Astronomers expect SN 2014J to continue brightening for a few more weeks. It may be visible in binocular by early February.

M82 (aka the Cigar Galaxy) is located in the constellation Ursa Major and is a popular target for small telescopes. It’s undergoing a period of extensive star formation that makes it many times brighter than our own Milky Way galaxy.

Image Credit: NASA

A UV View of Andromeda


This mosaic of M31 merges 330 individual images taken by the Ultraviolet/Optical Telescope aboard the Swift spacecraft. It is the highest-resolution image of the galaxy ever recorded in the ultraviolet. Also known as the Andromeda Galaxy, M31 is more than 220,000 light-years across and lies 2.5 million light-years away. On a clear, dark night, the galaxy is faintly visible as a misty patch to the naked eye.

The irregular shape of the image results when the more than 300 images were assembled to make the final image.

There are three instruments on Swift—a UV telescope, an X-ray telescope, and the Burst Alert Telescope which serves as the gamma ray burst detector for the spacecraft. I contributed to the design of the ultra-quiet regulators powering the detector blocks in the BAT.

Image Credit: NASA /Swift / Stefan Immler (GSFC) and Erin Grand (UMCP)

A Stellar Death Spiral


Roughly 290 million years ago, a star more or less like the Sun got too close to the central black hole of its galaxy. Intense tides tore the star apart and the resulting outburst of visible, ultraviolet and X-ray light first reached Earth in 2014. Observations from the Swift satellite have mapped out how and where these different wavelengths were produced as the shattered star’s debris circled the black hole. This animation illustrates how debris from a tidally disrupted star collided with itself, creating shock waves that emit ultraviolet and visible light. According to the Swift observations, that debris then took about a month to fall back to the black hole, where they produced changes in its X-ray emission that correlated with the earlier UV and visible light bursts.

Video Credit: NASA