Author Archives: Shannon Hall

Shannon Hall

About Shannon Hall

Shannon Hall, a freelance science journalist, has two B.A.'s in physics-astronomy and philosophy, as well as an M.S. in physics (with an emphasis in astronomy). She is currently working toward a second M.S. in science journalism.

This artist’s conception shows a terrestrial exoplanet, a gas giant and a mid-sized gas dwarf. Image credit: J. Jauch.

Three Exoplanet Molds: Metals Matter

Data from NASA's Kepler space telescope point to three distinct molds of exoplanets — rocky worlds, gas dwarfs, and ice/gas giants — distinguishable based on the abundances of heavy elements in their host star’s atmosphere.

In this image, NuSTAR data, which show high-energy X-rays from radioactive material, are colored blue. Lower-energy X-rays from non-radioactive material, imaged previously with NASA's Chandra X-ray Observatory, are shown in red, yellow and green.
NASA/JPL-Caltech/CXC/SAO

Quark Nova Spotted in Cas A?

Two elements deep within Cassiopeia A, hint the supernova remnant underwent a quark nova — a theoretical second explosion that leaves behind a quark star — just days after the original supernova.

standardcandle_480

Mysteriously Bright Supernova Explained

In 2010, a mysteriously bright supernova appeared, later sparking a debate within the astronomy community. But new images of the now-faded supernova reveal an intervening — and until now invisible — cosmic lens, which magnified its light.

This artist's concept illustrates two planetary systems - 55 Cancri (top) and our own. Blue lines show the orbits of planets, including the dwarf planet Pluto in our solar system. The 55 Cancri system is currently the closest known analogue to our solar system, yet there are some fundamental differences. 
NASA / JPL-Caltech

Planets’ Wacky Orbits Solved

By combining nearly 1,500 observations with sophisticated computer models, astronomers have shed light on a nearby planetary system, proving that the planets' bizarre orbits will actually remain stable for the next 100 million years.

The Hubble Space Telescope captured this image of the Stingray Nebula, the youngest known planetary nebula. In this image, the bright central star is in the middle of the green ring of gas. Its companion star is diagonally above it at 10 o'clock. The red curved lines represent bright gas that is heated by a "shock" caused when the central star's wind hits the walls of the bubbles. The nebula is as large as 130 solar systems, but, at its distance of 18,000 light-years, it appears only as big as a dime viewed a mile away. The colors shown are actual colors emitted by nitrogen (red), oxygen (green) and hydrogen (blue).
NASA

Watch a Star Evolve in “Real Time”

The odd behavior of a star in the heart of the Stingray Nebula provides tantalizing evidence that we may be seeing, first-hand, its helium-shell flash: an explosive phase of nuclear burning at the end of a star’s life.

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Most “Earth-Like” Planet Found Yet

The newly discovered planet, Kepler-186f, is the first Earth-size exoplanet circling in its star’s habitable zone. The media worldwide is gleaming with fantastical headlines, but readers in the know may have an inkling the result is less than it seems.

A supernova remnant about 24,000 light years from Earth.

Supernova Remnant in Technicolor

Take a look at this supernova remnant from radio waves to x-rays to see multiple features of its bubble-like expanding shock wave. Supernovae — the dramatic explosions of massive stars ending their lives — can outshine their host galaxies for weeks, allowing them to be seen across millions of light-years of empty space. On...