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Astronomers using the Hubble Space Telescope are examining one of the largest structures in the universe as part of a quest to understand the violent lives of galaxies. Hubble is providing evidence of unseen dark matter tugging on galaxies in the crowded, rough-and-tumble environment of a massive supercluster of hundreds of galaxies. Dark matter is an invisible form of matter that accounts for most of the universe’s mass. Hubble’s Advanced Camera for Surveys has mapped the invisible dark matter scaffolding superclusters as well as the detailed structure of individual galaxies embedded in it.

The dark matter map was constructed by measuring the distorted shapes of over 60,000 faraway galaxies. To reach Earth, the galaxies’ light traveled through the dark matter that surrounds the supercluster galaxies and was bent by the massive gravitational field. Heymans used the observed, subtle distortion of the galaxies’ shapes to reconstruct the dark matter distribution in the supercluster using a method called weak gravitational lensing. The dark matter map is 2.5 times sharper than a previous ground-based survey of the supercluster.

Stars:

Supernova explosions pose a threat to human life, however small. When a star explodes, most of its energy will be absorbed in the vast emptiness of space. Cosmic rays would be diffused by magnetic fields, and most of the damaging light would not affect life on Earth. But it is believed long-term exposure to blue-enhanced light could interfere with life. Those who study chronobiology, or the effects of biological timing, have found that low levels of blue light can strongly affect the endocrine systems of mammals by causing physiological and alerting responses. Blue-enhanced light is associated with reduced levels of melatonin production and affects circadian rhythms. For these reasons, it is sometimes prescribed to counteract seasonal affective disorder (SAD) or winter depression. Blue light can increase insomnia, reduce resistance to infection and is being studied as a possible risk of cancer.

Stars:

Mysterious ‘Blue Lights’ discovered about 12 million light-years away are clusters of orphan stars that formed in an unlikely part of the universe. An analysis of archived high-resolution images from the Hubble Space Telescope have revealed that the stars were clusters of mostly young stars. Scientists were surprised by the find, because the clusters of massive stars sit along a wispy bridge of gases it collided with 200 million years ago. This means that the stars are in the middle of a great void.

Stars:

Astronomers have now found new evidence of matter that spirals outward from a young star like a jetstream. Due to this spiral motion, the jets help the star to grow by drawing momentum from the surrounding disk. Angular momentum is the tendency for a spinning object to continue spinning. It applies to star formation because a star forms at the center of a rotating disk of hydrogen gas. A star grows by gathering material from the disk. However, gas cannot fall inward toward the star until that gas sheds its excess angular momentum. As hydrogen nears the star, a fraction of the gas is ejected outward perpendicular to the disk in opposite directions, like water from a fire hose, in a bipolar jet. If the gas spirals around the axis of the jet, then it will carry angular momentum with it away from the star.

Stars: