Category Astronomy/Space

The bright object seen in this Hubble image is a single and little-studied star named TYC 3203-450-1, located in the constellation of Lacerta (The Lizard). The star is much closer than the much more distant galaxy. Credit: NASA/ Hubble ESA

Galaxy NGC 7250, despite being remarkable in its own right – it has bright bursts of star formation and recorded supernova explosions – it blends into the background somewhat thanks to the gloriously bright star hogging the limelight next to it. The bright object seen in this Hubble image is a single and little-studied star named TYC 3203-450-1, located in the constellation of Lacerta (The Lizard). The star is much closer than the much more distant galaxy.

Only this way can a normal star outshine an entire galaxy, consisting of billions of stars...

1. Visualization constructed from simulation of Chariklo’s double ring.
(Credit: Shugo Michikoshi, Eiichiro Kokubo, Hirotaka Nakayama, 4D2U Project, NAOJ)
2. Simulation of Chariklo’s ring system. Using a particle density equal to half of Chariklo’s density, the overall structure can be maintained. In the close-up view (right) complicated, elongated structures are visible. These structures are called self-gravity wakes. The numbers along the axes indicate distances in km. (Credit: Shugo Michikoshi (Kyoto Women’s University/University of Tsukuba))

A team in Japan modeled the 2 rings around Chariklo, the smallest body in the Solar System known to have rings...

Visualization was constructed from simulation of Chariklo’s double ring. Credit: Shugo Michikoshi, Eiichiro Kokubo, Hirotaka Nakayama, 4D2U Project, NAOJ

A team in Japan modeled the 2 rings around Chariklo, the smallest body in the Solar System known to have rings. This is the first time an entire ring system has been simulated using realistic sizes for the ring particles while also taking into account collisions and gravitational interactions between the particles. The team’s simulation revealed information about the size and density of the particles in the rings. By considering both the detailed structure and the global picture for the first time, the team found that Chariklo’s inner ring should be unstable without help...

This schematic representation illustrates the technique used to probe the small-scale structure of the cosmic web using light from a rare quasar pair.
Credit: J. Onorbe / MPIA

A team of astronomers have made the first measurements of small-scale ripples in this primeval hydrogen gas using rare double quasars. Although the regions of cosmic web they studied lie nearly 11 billion light years away, they were able to measure variations in its structure on scales 100,000 times smaller, comparable to the size of a single galaxy.

Intergalactic gas is so tenuous that it emits no light of its own. Instead astronomers study it indirectly by observing how it selectively absorbs the light coming from faraway sources known as quasars...