Born with Flare!
by Charles Telesco
In this article, he talks about the circumstellar disks from which planets are formed.
Planets are formed from the stars! Stars which consist of huge amount of gases and dust particles emit heat in the form of ultraviolet rays. The main gaseous element is Hydrogen and the solid dust particles emit infrared radiation.
Supernova explosion causes stellar gases and dust particles to be released in the space. supernova (plural: supernovae) is a stellar explosion which produces an extremely luminous object made of plasma. A supernova may briefly out-shine its entire host galaxy before fading from view over several weeks or months. It would take 10 billion years for the Sun to produce the energy output of an ordinary, Type II supernova, the explosion expels much or all of a star's material with great force, driving a shock wave into the surrounding space, forming a supernova remnant. Thus, planets are part of the life cycle of star formation.
Star formation: Interstellar clouds made of gases and dust particles, clump and collapse. The core of each compressed cluster heats up to fuse hydrogen – turns into a star
The European Southern observatory-Lagage et al studied the circumstellar disk of a star HD97048 using an infrared camera placed on a 8 m long telescope. They have put forward certain important observations. Flared disk is saucer-shaped and is thicker at the edge compared to the centre. Surfaces on opposite sides of saucer are like bowls which face away from each other. We see only near surface of the flare disk because the dust particle in the disk are so numerous that infrared radiation which is much less absorbed by dust than visible light is sharply attenuated from far surface. High dust density and resultant high opacity (impossible to see through) indicate that disk is very young. And no enough time has passed for dust particles to coalesce into large bodies or be removed by stellar radiation pressure. That means more giant planets are yet to come! Flaring results as star’s gravitational force is directed towards midplane and decreases with increasing distance from the star.
Thus, flared disk plays very important role in planet formation. Hence, today astronomers are working furiously to discover more about these disks. Also, presence of gas is prerequisite for giant-planet formation. Conditions and time scales needed for planet formation are strong
function of stellar mass.
References:
[1] Charles Telesco, “Born with Flare,” Science, vol. 314, pp. 605-606,
2006
[2] NASA AERONAUTICS AND SPACE ADMINISTRATION,
“Planetary Evolution”Available HTTP: http://ares.jsc.nasa.gov/AstroResearch/planetary.htm
[3] Wikipedia, free encyclopedia, “Solar System”
Available HTTP:
http://encyclopedia.calendarhome.com/Solar_system.htm
[4] Northwestern University, Dept of Geological Sciences, “Planets formed
as part of life cycle of star formation”Available HTTP:
http://www.earth.northwestern.edu/individ/seth/107/Solar/planetform.htm
[5] NASA Goddard Space Flight Center, Smithsonian Astrophysical
Observatory, “Supernova”Available HTTP: http://heasarc.gsfc.nasa.gov/docs/snr.html
[6] Wikipedia, “Supernova”
Available HTTP: http://en.wikipedia.org/wiki/Supernova