Cosmic dust.  It is found throughout the Universe.  But little is known of its origins or how it grows.  But now a team of scientists using ESO's Very Large Telescope in Chile has studied a supernova over the course of several years and has learned much about the dust formed in the explosion.

They found that dust formation begins soon after the explosion and continues for a long period of time.  But the astronomers think the dust formed in the material the star shed out into space BEFORE it exploded.  A cool dense shell of gas is formed as the supernova's shockwave expands.  These are the ideal conditions for the dust grains to seed and grow.  But this is only the first stage.

The second stage begins several hundred days after the explosion.  This is an accelerated dust formation process in the ejected material from the supernova.

The team was also able to answer the question of how the dust can survive the massive explosion.  They observed the dust grains are larger than one thousandth of a millimeter and form rapidly in the dense material surrounding the star.  The size of the grains is larger than expected and explains how they survive the explosion.

It has been found that many exoplanets have strange inclined orbits around their sun, unlike our solar system where the planets orbit in the same plane.  Observing planets being formed in the HK Tauri binary system, we see this phenomena taking place.  Using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, astronomers have gotten the first closeup views and the sharpest photos ever of planet formation in a double star system.

The HK Tauri system is found in the constellation Taurus.  The stars are less than five million years old and orbit each other at a distance of 58 billion kilometers.  HK Tauri B is the fainter of the two stars and we view the planet forming disk edge-on.  HK Tauri A is the brighter star and we view it straight-on.

The disk of HK Tauri A is so bright we cannot view it optically, but using the millimeter wavelengths which ALMA sees, the planet disks come into view.  One of the disks is tilted over 60 from the plane of the other and is not in the plane of orbit of the two stars.

One theory of why this occurs is the gravitational forces of the two stars impacting the disks of gas and dust as they begin to rotate around their respective star.  Scientists now need to study other planet forming stars to see if this is common in the Milky Way or not.

An open cluster is a group of stars formed at the same time out of the same cloud of dust and gas.  As a result, all the stars contain the same chemical makeup.  But the stars in a cluster are not always alike in size.

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This photo is of the open cluster NGC 3293, found in the constellation Carina.  It was taken with ESO's La Silla Observatory in Chile.  The stars are all less than 10 million years old, making them young stars.  But notice that there is a red giant in the litter.  A red giant is a star nearing the end of its life, expanding and cooling down.  But this red giant is the same age as the other bluish stars you see.

The red giant was born as a large star compared to its sibling stars.  Since it was so big, it burned its fuel at a faster speed than the other stars.  In essence, it aged faster and burnt out faster than the others.  These stars are only 10 million years old, compared to our sun that is 4.6 BILLION years old.  Yet this young star, being born so large, has reached old age very quickly.

By studying star clusters, astronomers can compare stars formed at the same time out of the same cloud of gas.  Looking at the differences amongst these stars, they gain valuable knowledge in the life and behavior of stars.

There are two types of star clusters.  Open clusters, as this cluster is, and Globular clusters.  Open clusters have less stars in them and are much younger than stars found in a Globular cluster.  Because there are less stars in an Open cluster, over time the cluster's gas and dust dissipates and the gravitation no longer holds the stars near each other.  The large density of stars in a Globular cluster on the other hand, create enough gravity that the cluster stays together for billions of years.  So you typically find very old stars in a Globular cluster but only young stars in an Open cluster.

Gamma-rays are the most energetic forms of light we know of in the Universe.  They are formed in powerful cosmic blasts like supernovae.  But, until now, no one thought they could be formed in smaller Nova explosions.

A nova occurs when a thermonuclear explosion takes place on the surface of a white dwarf star.  Each nova releases 100,000 times the annual energy of our sun.  Now NASA's Fermi Gamma-Ray space telescope has detected gamma-ray busts in not one, but four nova explosions.

What drives this is unknown.  Where could so much energy come from?  One theory is that a nova will create multiple shock waves expanding at different speeds.  When the faster waves overtake the slower waves, the particles in them accelerate to near light speed.  These particles then produce the gamma-rays.