Category Astronomy/Space

The gamma-ray excess (shown in yellow-white) at the heart of M31 hints at unexpected goings-on in the galaxy’s central region. Scientists think the signal could be produced by a variety of processes, including a population of pulsars or even dark matter. Credit: NASA/DOE/Fermi LAT Collaboration and Bill Schoening, Vanessa Harvey/REU program/NOAO/AURA/NSF

NASA’s Fermi Gamma-ray Space Telescope has found a signal at the center of the neighboring Andromeda galaxy that could indicate the presence of dark matter. The gamma-ray signal is similar to one seen by Fermi at the center of our own Milky Way galaxy. Gamma rays are the highest-energy form of light, produced by the universe’s most energetic phenomena...

An infographic describing three theories on how the Earth got its iron signature.Designed by Laura Martin/The University of Texas at Austin Jackson School of Geosciences. Images 1 and 2 from NASA/JPL-Caltech, Image 3 from X-Science, Earth from NASA/JPL.

New research from The University of Texas at Austin reveals that the Earth’s unique iron composition isn’t linked to the formation of the planet’s core, calling into question a prevailing theory about the events that shaped our planet during its earliest years.The research, opens the door for other competing theories about why the Earth, relative to other planets, has higher levels of heavy iron isotopes...

NGC 5907 X-1: record-breaking pulsar

ESA’s XMM-Newton has found a pulsar the spinning remains of a once-massive star that is a 1000X brighter than previously thought possible. The pulsar is also the most distant of its kind ever detected, with its light travelling 50 million light-years before being detected by XMM-Newton. Pulsars are spinning, magnetised neutron stars that sweep regular pulses of radiation in two symmetrical beams across the cosmos. If suitably aligned with Earth these beams are like a lighthouse beacon appearing to flash on and off as it rotates. They were once massive stars that exploded as a powerful supernova at the end of their natural life, before becoming small and extraordinarily dense stellar corpses.
This X-ray source is the most luminous of its type detected to...

(a) Open-shutter photograph of fireball EN09121418 taken by Dr. Spurny (coauthor) at the Czech Fireball Network. (b) Intensity at a slant distance of 100 km for fireball EN091214 from Dr. Spurny. The CFN radiometers have flat response below 5 kHz. Intensity curves from different fireballs are in supplementary section. (c) Fourier transform of intensity-time history along with the normalized gain of the human ear for reference.

When a meteor is about to conk your neighborhood and gives fair warning by emitting sizzling, rustling and hissing sounds as it descends, you might think that the universe is being sporting...