Category Astronomy/Space

Dwarf galaxies have few stars but lots of dark matter. This Caltech FIRE (Feedback in Realistic Environments) simulation from shows the predicted distribution of stars (left) and dark matter (right) around a galaxy like the Milky Way. The red circle shows a dwarf galaxy like Triangulum II. Although it has a lot of dark matter, it has very few stars. Dark matter-dominated galaxies like Triangulum II are excellent prospects for detecting the gamma-ray signal from dark matter self-annihilation. Credit: A. Wetzel and P. Hopkins, Caltech

A researcher has measured what could be the highest concentration of dark matter in any known galaxy. Dark matter is called “dark” for a good reason...

Image shows a composite where blue represents the MagAO data taken at H-alpha, and green and red show the LBT data taken at Ks and L’ bands. The greyscale is a previously published millimeter image of the disk. Credit: Photo credit: Stephanie Sallum

Capturing sharp images of distant objects is difficult, largely due to atmospheric turbulence, the mixing of hot and cold air. But researchers captured the first photo of a planet in the making, a planet residing in a gap in LkCa15’s protoplanetary disk. Of the roughly 2,000 known exoplanets, only about 10 have been imaged – and long after they had formed, not when they were in the making.

Protoplanetary disks form around young stars using the debris left over from the star’s formation...

Chandra image of the black hole at the center of spiral galaxy M81. Credit: X-ray: NASA/CXC/Wisconsin/D.Pooley & CfA/A.Zezas; Optical: NASA/ESA/CfA/A.Zezas; UV: NASA/JPL-Caltech/CfA/J.Huchra et al.; IR: NASA/JPL-Caltech/CfA

A high-performance computing researcher has predicted a physical effect that would help physicists and astronomers provide fresh evidence of the correctness of Einstein’s general theory of relativity. Bin Chen, who works at the university’s Research Computing Center, describes the yet-to-be-observed effect in the paper “Probing the Gravitational Faraday Rotation Using Quasar X-ray Microlensing,” in the journal Scientific Reports. “To be able to test general relativity is of crucial importance to physicists and astronomers,” Chen said.

This testing is especially so in re...

The planet Kepler-438b is shown here in front of its violent parent star. It is regularly irradiated by huge flares of radiation, which could render the planet uninhabitable. Here the planet’s atmosphere is shown being stripped away. Credit: With credit to Mark A Garlick/University of Warwick

The most Earth-like planet could have been made uninhabitable by vast quantities of radiation.The atmosphere of the planet, Kepler-438b, is thought to have been stripped away as a result of radiation emitted from a superflaring red dwarf star, Kepler-438. Regularly occurring every few hundred days, the superflares are approximately 10X more powerful than those ever recorded on the sun and equivalent to the same energy as 100 billion megatons of TNT.

While superflares themselves are unlikely to have a ...