Category Astronomy/Space

Why is the Universe Ripping Itself Apart? A new study shows Dark Energy may be more complicated than we thought

A small star slurping material from a much larger one.
In a Type Ia supernova, a white dwarf slowly pulls mass from a neighboring star before exploding. NASA / JPL-Caltech, CC BY

What is the universe made of? This question has driven astronomers for hundreds of years.

For the past quarter of a century, scientists have believed “normal” stuff like atoms and molecules that make up you, me, Earth, and nearly everything we can see only accounts for 5% of the universe. Another 25% is “dark matter”, an unknown substance we can’t see but which we can detect through how it affects normal matter via gravity.

The remaining 70% of the cosmos is made of “dark energy”. Discovered in 1998, this is an unknown form of energy believed to be making the universe expand at an ever-increasing rate.

In a new study soon to be published in the Astronom...

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Fermi Gamma-ray Space Telescope detects Surprise Gamma-Ray feature Beyond our Galaxy

Artist's concept of gamma ray sky with dipole marked in magenta
This artist’s concept shows the entire sky in gamma rays with magenta circles illustrating the uncertainty in the direction from which more high-energy gamma rays than average seem to be arriving. In this view, the plane of our galaxy runs across the middle of the map. The circles enclose regions with a 68% (inner) and a 95% chance of containing the origin of these gamma rays.
NASA’s Goddard Space Flight Center

Astronomers analyzing 13 years of data from NASA’s Fermi Gamma-ray Space Telescope have found an unexpected and as yet unexplained feature outside of our galaxy.

“It is a completely serendipitous discovery,” said Alexander Kashlinsky, a cosmologist at the University of Maryland and NASA’s Goddard Space Flight Center in Greenbelt, who presented the research at the 243rd mee...

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Unlocking the Secrets of a ‘Hot Saturn’ and its Spotted Star

Led by researchers from Université de Montréal’s Trottier Institute for Research on Exoplanets (iREx), a team of astronomers has harnessed the power of the revolutionary James Webb Space Webb Telescope (JWST) to study the “hot Saturn” exoplanet HAT-P-18 b.

Their findings, published last month in the journal Monthly Notices of the Royal Astronomical Society, paint a complete picture of the HAT-P-18 b’s atmosphere while exploring the great challenge of distinguishing its atmospheric signals from the activity of its star.

HAT-P-18 b is located over 500 light-years away with a mass similar to Saturn’s but a size closer to that the larger planet Jupiter. As a result, the exoplanet has a “puffed-up” atmosphere that is especially ideal for analysis.

Passing over a spotted star

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Nube, the Almost Invisible Galaxy that Challenges the Dark Matter Model

Nube, the almost invisible galaxy that challenges the dark matter model
The Nube galaxy. The figure is a composition of a color image and a black and white image, to pick out the background. Credit: GTC/Mireia Montes

Nube is an almost invisible dwarf galaxy discovered by an international research team led by the Instituto de Astrofísica de Canarias (IAC) in collaboration with the University of La Laguna (ULL) and other institutions.

The name was suggested by the 5-year-old daughter of one of the researchers in the group and is due to the diffuse appearance of the object. Its surface brightness is so faint that it had passed unnoticed in the various previous surveys of this part of the sky due to the object’s diffuse appearance as if it were some kind of ghost...

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