SciPak

Probing and Proving Theories of Gravitation

Observations of a massive neutron star in a compact stellar binary in outer space confirm general relativity theory in a previously untested regime, a new study reports. General relativity (GR), proposed by Albert Einstein, has been tested outside of Earth before, but it has not been tested in the strong field of such a massive neutron star (or other, even stronger gravitational fields). Thus, scientists haven’t known whether this theory applies in such extreme environments. Now, new research by John Antoniadis and colleagues tests this theory in a strong-field setting.

Read more about this research from the 26 April issue of Science here.

[Image courtesy of European Southern Observatory / J. Antoniadis (MPIfR). Click the image for more information.]

Atmosphere of Distant Exoplanet Described By Its Spectrum

A young exoplanet, orbiting a star known as HR 8799, has water and carbon monoxide in its atmosphere — but not methane — researchers say. The findings suggest that a planet-forming mechanism, called core accretion, brought the exoplanet into existence, rather than another possible process, known as gravitational instability.

Read more and listen to a teleconference about this research from the 14 March issue of Science Express here.

[Image courtesy of Dunlap Institute for Astronomy & Astrophysics; Mediafarm. Click the image for more information.]

Radar Reveals Underground Flood Channels on Mars

Researchers have produced a three-dimensional reconstruction of Marte Vallis, the largest of the outflow channels that were carved into Mars — presumably by an ancient mega-flood — within the past 500 million years. The analysis reveals that the buried flood channels are actually twice as deep as researchers had believed, and that the series of fissures known as Cerberus Fossae likely provided the source of that ancient floodwater.

Read more about this research from the 7 March issue of Science Express here.

[Image courtesy of NASA/MOLA Team/Smithsonian Institution. Click the image for more information.]

Black Hole ‘Mystery Structure’ in X-Ray Binary

New observations of an X-ray binary system may help expand current understanding of black hole accretion and jet collimation. Binary star systems consist of two stars that orbit around their common center of mass. X-ray binaries are a special type of binary system that emit X-rays and are made up of a normal star and a collapsed star (a black hole or neutron star). X-ray binaries can stay quiet for centuries, but occasionally the system can erupt, generating a burst of brightness that can be detected by X-ray telescopes.

This video, courtesy of Gabriel Perez Diaz at Instituto de Astrofisica de Canarias (Servicio MultiMedia), and narrated by author Jesús Corral-Santana, discusses the X-ray binary system.

Read more about this research from the 1 March issue of Science here.

Accelerated Protons Confirm Origin of Cosmic Rays

A new study offers conclusive evidence that cosmic ray protons within our galaxy are accelerated in the shock waves produced by supernovae.

Read more about this research from the 15 February issue of Science here.

[Image courtesy of Greg Stewart, SLAC National Accelerator Laboratory. Click the image for more information.]

Study Reveals Long-Sought Secret of the Stars

Stellar outbursts used to be lumped into two categories: novae or supernovae. But, over the years, researchers have recognized another class of outbursts with luminosities between those of novae and supernovae, called intermediate-luminosity red transients or ILRTs. Now, Natalia Ivanova and colleagues suggest that these ILRTs are actually the signatures of phenomena known as common-envelope events, which have only been theorized but never observed directly.

Read more about this research from the 25 January issue of Science here.

[Image courtesy of NASA, ESA, and The Hubble Heritage Team (STScI/AURA). Click the image for more information.]

ScienceShot: Hubble Spies Oldest Galaxies Yet

Credit: NASA/ESA/UDF12

Buried in this image of a minute patch of the night sky are remote galaxies so faint (marked by diamonds, above) that it took the Hubble Space Telescope more than 100 hours to register their feeble light. Obtained last fall, the Ultra Deep Field 2012 provides astronomers with the deepest view yet of the very early universe. An analysis of the observed properties of the most distant objects, presented at the 221st meeting of the American Astronomical Society, indicates that there must be a huge, unobserved population of even fainter galaxies. The energy of newborn stars in these primordial galaxies was responsible for heating up the cold hydrogen gas in intergalactic space, just a few hundred million years after the big bang. Astronomers expect that the future James Webb Space Telescope, due to be launched in 2018, will succeed in actually imaging these faint objects, so stay tuned for an even deeper field.

For more information, visit ScienceNow.

New Space Rock Is Rare Type of Meteorite

On April 22, 2012, several Doppler weather radars detected a fast-moving fireball that many spectators also saw in the skies over California and Nevada. A new study describes the speedy recovery of this meteorite and reports that the space rock is an unusually complex example of the rare meteorites known as carbonaceous chondrites. The meteorite is called the Sutter’s Mill meteorite, after the spot where some of the fragments were found.

Read more about this research from the 21 December issue of Science here.

[Image courtesy of NASA / Eric James; click the image for more information.]

Varying Fundamental Constants

The Standard Model of particle physics is built on the fundamental constants of nature, yet the model does not adequately explain their values or require their constancy over space and time. Searching for time-varying fundamental constants offers a way to look for new physics beyond the Standard Model. Here, Julija Bagdonaite and colleagues explore the possible variation of the fundamental constant μ, which represents the proton-to-electron mass ratio in the Standard Model.

Read more about this research from the 13 December issue of Science Express here.

[Image courtesy of Paul Jansen; click the image for more information.]

Could Regular Moons Come From Ring Systems?

Most astronomers believe that the massive moons of Jupiter, including Io, Europa, Ganymede and Callisto, were born from a large gaseous disk that surrounded the planet during its formation. However, until now, the processes that brought smaller moons, particularly those around Uranus, Neptune and Pluto, into existence has remained a mystery. Aurélien Crida and Sébastien Charnoz now suggest that most moons in the solar system were born from massive ring systems that once surrounded the planets.

Read more about this research from the 30 November issue of Science here.

[Image courtesy of Frederic Durillon | animea; click the image for more information.]