Astrohaze

There is a new Astrohaze forum coming soon.

I think, as i do Art, we should start a Astronomy Contest. I will enclose a piece of art of mine (but won't enter the contest), and want to see Astronomy Art work because there is not alot! Entries can be entered anytime, because it is an ongoing contest.

[I hope to actually get some entries this time]

 

Source:Astrohaze

Website:http://astrohaze.spaces.live.com

Hi, all. This is a contest for Astronomy/Celestial Poetry. Anyone who wants to enter please sent an email with the subject 'Celestial Poetry' and the name of the poem to lukeh46@hotmail.com. Entries for the first contest are no accepted after 11th August 2006. Thanks, theres a example below about Slacker Astronomy [www.slackerastronomy.org] and the demotion of Pluto.

 

 

 

 

 

Looking in detail at the composition of stars with ESO's VLT, astronomers are providing a fresh look at the history of our home galaxy, the Milky Way. They reveal that the central part of our Galaxy formed not only very quickly but also independently of the rest.

"For the first time, we have clearly established a 'genetic difference' between stars in the disc and the bulge of our Galaxy," said Manuela Zoccali, lead author of the paper presenting the results in the journal Astronomy and Astrophysics. "We infer from this that the bulge must have formed more rapidly than the disc, probably in less than a billion years and when the Universe was still very young."

The Milky Way is a spiral galaxy, having pinwheel-shaped arms of gas, dust, and stars lying in a flattened disc, and extending directly out from a spherical nucleus of stars in the central region. The spherical nucleus is called a bulge, because it bulges out from the disc. While the disc of our Galaxy is made up of stars of all ages, the bulge contains old stars dating from the time the galaxy formed, more than 10 billion years ago. Thus, studying the bulge allows astronomers to know more about how our Galaxy formed.

To do this, an international team of astronomers analysed in detail the chemical composition of 50 giant stars in four different areas of the sky towards the Galactic bulge. They made use of the FLAMEs/UVES spectrograph on ESO's Very Large Telescope to obtain high-resolution spectra.

The chemical composition of stars carries the signature of the enrichment processes undergone by the interstellar matter up to the moment of their formation. It depends on the previous history of star formation and can thus be used to infer whether there is a 'genetic link' between different stellar groups. In particular, comparison between the abundance of oxygen and iron in stars is very illustrative. Oxygen is predominantly produced in the explosion of massive, short-lived stars (so-called Type II supernovae), while iron instead originates mostly in Type Ia supernovae [3], which can take much longer to develop. Comparing oxygen with iron abundances therefore gives insight on the star birth rate in the Milky Way's past.

"The larger size and iron-content coverage of our sample allows us to draw much more robust conclusions than were possible until now," said Aurelie Lecureur, from the Paris-Meudon Observatory (France) and co-author of the paper.

The astronomers clearly established that, for a given iron content, stars in the bulge possess more oxygen than their disc counterparts. This highlights a systematic, hereditary difference between bulge and disc stars.

"In other words, bulge stars did not originate in the disc and then migrate inward to build up the bulge but rather formed independently of the disc," said Zoccali. "Moreover, the chemical enrichment of the bulge, and hence its formation timescale, has been faster than that of the disc."

Comparisons with theoretical models indicate that the Galactic bulge must have formed in less than a billion years, most likely through a series of starbursts when the Universe was still very young.

 

Source:ESO

Link:http://www.eso.org

 

Saturn's B and C rings disappear behind the immense planet. Where they meet the limb, the rings appear to bend slightly owing to upper-atmospheric refraction.

Crenulations -- irregularly wavy or serrated features -- in the planet's clouds denote the locations of turbulent belt/zone boundaries.

The image was taken using a spectral filter sensitive to wavelengths of infrared light centered at 728 nanometers. The view was obtained with the Cassini spacecraft wide-angle camera on Aug. 16, 2006 at a distance of approximately 256,000 kilometers (159,000 miles) from Saturn. Image scale is 12 kilometers (7 miles) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

Source:NASA/JPL/Space Science Institute

Link:http://saturn.jpl.nasa.gov