Jan. 23, 2013 ? In space, dense clouds of cosmic gas and dust are the birthplaces of new stars. In visible light, this dust is dark and obscuring, hiding the stars behind it. So much so that, when astronomer William Herschel observed one such cloud in the constellation of Scorpius in 1774, he thought it was a region empty of stars and is said to have exclaimed, "Truly there is a hole in the sky here!" [1]
In order to better understand star formation, astronomers need telescopes that can observe at longer wavelengths, such as the submillimetre range, in which the dark dust grains shine rather than absorb light. APEX, on the Chajnantor Plateau in the Chilean Andes, is the largest single-dish submillimetre-wavelength telescope operating in the southern hemisphere, and is ideal for astronomers studying the birth of stars in this way.
Located in the constellation of Orion (The Hunter), 1500 light-years away from Earth, the Orion Molecular Cloud Complex is the closest region of massive star formation to Earth, and contains a treasury of bright nebulae, dark clouds and young stars. The new image shows just part of this vast complex in visible light, with the APEX observations overlaid in brilliant orange tones that seem to set the dark clouds on fire. Often, the glowing knots from APEX correspond to darker patches in visible light -- the tell-tale sign of a dense cloud of dust that absorbs visible light, but glows at submillimetre wavelengths, and possibly a site of star formation.
The bright patch below of the centre of the image is the nebula NGC 1999. This region -- when seen in visible light -- is what astronomers call a reflection nebula, where the pale blue glow of background starlight is reflected from clouds of dust. The nebula is mainly illuminated by the energetic radiation from the young star V380 Orionis [2] lurking at its heart. In the centre of the nebula is a dark patch, which can be seen even more clearly in a well-known image (http://www.spacetelescope.org/images/opo0010a/) from the NASA/ESA Hubble Space Telescope.
Normally, a dark patch such as this would indicate a dense cloud of cosmic dust, obscuring the stars and nebula behind it. However, in this image we can see that the patch remains strikingly dark, even when the APEX observations are included. Thanks to these APEX observations, combined with infrared observations from other telescopes, astronomers believe that the patch is in fact a hole or cavity in the nebula, excavated by material flowing out of the star V380 Orionis. For once, it truly is a hole in the sky!
The region in this image is located about two degrees south of the large and well-known Orion Nebula (Messier 42), which can be seen at the top edge of the wider view in visible light from the Digitized Sky Survey.
The APEX observations used in this image were led by Thomas Stanke (ESO), Tom Megeath (University of Toledo, USA), and Amy Stutz (Max Planck Institute for Astronomy, Heidelberg, Germany). APEX is a collaboration between the Max Planck Institute for Radio Astronomy (MPIfR), the Onsala Space Observatory (OSO) and ESO. Operation of APEX at Chajnantor is entrusted to ESO.
Notes
[1] In German, "Hier ist wahrhaftig ein Loch im Himmel!"
[2] V380 Orionis has a high surface temperature of about 10,000 Kelvin (about the same in degrees Celsius), nearly twice that of our own Sun. Its mass is estimated to be 3.5 times that of the Sun.
Share this story on Facebook, Twitter, and Google:
Other social bookmarking and sharing tools:
Story Source:
The above story is reprinted from materials provided by European Southern Observatory - ESO.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
Note: If no author is given, the source is cited instead.
Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.
Source: http://feeds.sciencedaily.com/~r/sciencedaily/space_time/astronomy/~3/4cF5E2l0310/130123094558.htm
Happy new year fiscal cliff Pitbull Hannah Storm jenny mccarthy Psy fergie
The tiny, inexpensive Raspberry Pi has a very low power consumption, which makes it a great always-on VPN (Virtual Private Network) server. With a VPN, you'll get secure access to your home network when you're on the go and can use it for secure web browsing when you're on public networks. Here's how to roll your own VPN with the Raspberry Pi. 
If you haven't already, follow the steps in our Beginner's Guide to DIYing with the Raspberry Pi to create the base system running Raspbian, the standard operating system for the Pi.
Hamachi depends on a couple of packages that may not be present in your image, so we're going to first update the packages and hopefully save you time troubleshooting common errors.
Besides issuing remote commands to the Pi and accessing network files, you can use your Pi as a proxy server. By connecting Privoxy and Hamachi, you can secure and encrypt your browser sessions when you're using the public Wi-Fi at your local coffeeshop?keeping your data safe from prying eyes or malicious users.
