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Submission + - A Young Star in the Midst of Planet Formation Revealed by ALMA

ogre7299 writes:

Astronomers have captured the best image ever of planet formation around an infant star as part of the testing and verification process for the Atacama Large Millimeter/submillimeter Array’s (ALMA) new high-resolution capabilities. This revolutionary new image reveals in astonishing detail the planet-forming disk surrounding HL Tau, a Sun-like star located approximately 450 light-years from Earth in the constellation Taurus.

ALMA uncovered never-before-seen features in this system, including multiple concentric rings separated by clearly defined gaps. These structures suggest that planet formation is already well underway around this remarkably young star. The new ALMA image reveals these striking features in exquisite detail, providing the clearest picture to date of planet formation. Images with this level of detail were previously only seen in computer models and artist concepts. ALMA, living up to its promise, has now provided direct proof that nature and theory are very much in agreement.

Submission + - Billion Star Surveyor 'Gaia' Lifts Off

mrspoonsi writes: BBC Reports: Europe has launched the Gaia satellite — one of the most ambitious space missions in history. The 740m-euro (£620m) observatory lifted off from the Sinnamary complex in French Guiana at 06:12 local time (09:12 GMT). Gaia is going to map the precise positions and distances to more than a billion stars. This should give us the first realistic picture of how our Milky Way galaxy is constructed. Gaia's remarkable sensitivity will lead also to the detection of many thousands of previously unseen objects, including new planets and asteroids. Gaia will use this ultra-stable and supersensitive optical equipment to pinpoint its sample of stars with extraordinary confidence. By repeatedly viewing its targets over five years, it should get to know the brightest stars' coordinates down to an error of just seven micro-arcseconds. "This angle is equivalent to the size of a euro coin on the Moon as seen from Earth," explained Prof Alvaro Gimenez, Esa's director of science.

Comment Funding is from National Science Foundation (Score 2) 668

The funding for NRAO comes from the National Science Foundation, which is funded by the federal government. When an appropriations bill was not passed, NSF did not get any money, so they could not give any money to NRAO to continue operating. The National Science Foundation could not authorize NRAO to continue operating without funding. So, in short, this isn't being done to save money, it's being done because there is no money.

Comment Re:Misleading summary and first article (Score 5, Informative) 60

The article also washes over the fact that there are different telescopes for different parts of the radio spectrum. The MWA and LOFAR are the most powerful in the MHz regime, but the VLA is still the most powerful between 1 to 50 GHz, and ALMA is the most powerful from 85 and 700 GHz.

Submission + - Astronomers detect and 'weigh' very young solar system

ogre7299 writes: Astronomers have found direct evidence of a forming proto-solar system and 'weighed' the forming star for the first time as repored in a recent Nature paper paywalled arXiv version and highlighted on
Beneath a dusty disk of creation, a baby star's mass has been measured for the first time. The star, called L1527 IRS, is only one-fifth the mass of the sun, and is expected to keep growing as the swirling disk of matter surrounding it falls into its surface. Astronomers estimated the star formed around the same time that Neanderthals evolved on Earth: just 300,000 years ago.

Comment Re:First law violation (Score 2) 228

This is a huge error in the Wired article "The telescopes searched for alpha particles emitted by Hydrogen atoms (commonly found in star formation, appearing as a bright red light)." An alpha particle is the nucleus of a Helium atom, so if hydrogen could emit that it would be an incredible feat! However, they really mean H-alpha line emission, a bright emission line that comes from the recombination of a proton and electron and it can be measured out to high redshifts.

They aren't observing fusion since that process takes place deep inside the stars.

Comment Re:What about maintanance of Hubble? (Score 4, Informative) 115

While there have been other telescopes that observed in the infrared, JWST will have a mirror 6x larger than the prevous space-based telescopes that operate or have operated at the same wavelengths (0.8 to 24 microns). This means that JWST will have a factor of 6 better resolution than previous telescopes and be incredibly more sensitive due to the larger collecting area. Ground-based telescopes cannot compete with JWST because of the sky brightness in the infrared making sensitive observations very time consuming. The science drivers of JWST are primarily the high-redshift universe, that is galaxies that were formed shortly after the big bang. This is something Hubble cannot do since it is not infrared optimized (the telescope is quite warm compare to JWST's operating temperature) and has too small of an aperture for the resolution needed.

The lack of future Hubble servicing has a lot to do with the retirement of the Space Shuttles, the only platform that can be used to service HST. Hubble will be kept going as long as possible since it is still doing outstanding science. In the 2020s it is hoped to launch an 8m class optical-uv telescope to truly replace Hubble.

Comment Not an observation with the Array (Score 2) 64

The target will not be observed with the array of four telescopes, rather just one of the telescopes will do the observation. Taking data simultaneously with all four telescopes is a tricky procedure and yields data, while extremely useful scienfically, it's very different from the pretty pictures that this contest is after.

Comment Re:5 times younger? (Score 1) 16

FTFA: "LkCa 15 b is the youngest planet ever found, about 5 times younger than the previous record holder," said astronomer Adam Kraus of the University of Hawaii's Institute for Astronomy.

WTF is 5 times younger? Does he mean 1/5 as old? At the moment the planet first started to form, was it infinitely times younger? You'd think a scientist would know better.

Picky picky, do you have anything intelligent to add or are you just going to argue semantics rather than acknowledge good science?

This is actually a very important discovery, the circumstellar disk surrounding the young star has been found to have a deficit of emission ~55 AU in radius. The cause of holes or gaps in proto-planetary disks has been a matter of intense debate in recent years, some people favor planets clearing gaps, others favor emission from the star causing the disk to evaporate. This seems to be clear evidence that planets are actually doing the gap opening and play a key role in the dissipation of disks around stars.

Comment Re:Terrible airline. (Score 1) 143

Not all of American's jets have in-seat entertainment. The entire 767 fleet does not have in-seat entertainment, merely the overhead screens. The 777 fleet does have the in-seat screens, but perhaps you would get different options, and your laptop screen is probably nicer to watch something off of than the small ones in the seat.

As for American being a terrible airline, I have to disagree with you. Perhaps they're not a nice as some of the international carriers due to the cut-throat market in the US, but I have been quite happy with my experiences flying them for domestic and international purposes.

Comment Re:Well, that figures (Score 2) 98

The VLA is not being closed, it has been substantially upgraded and is now known as the EVLA, E for expanded. The array being constructed in Chile ALMA the Atacama Large Millimeter Array operates at higher frequencies 88GHz to ~700 GHz whereas the EVLA operates between 74MHz and 50 GHz. They are complementary facilities, in addition, ALMA is a multinational project, Europe, Japan, and the US. Arecibo has been under discussion for closure for many years; however, to restore the site to its natural state (as required by contract) would cost much more than keeping it running.

Science is popular; however, progress comes slowly these days and a lot must go on behind the scenes before something of broad interest comes out. The new facilities like the EVLA, ALMA, and the Large Hadron Collider are able to make ground breaking discoveries that are difficult to achieve with more limited instrumentation.

Comment Re:The future of telescopes. (Score 1) 185

I missed a point here, you seemed to be implying using these for optical interferometry. However, we cannot currently digitize an optical signal and current optical interferometers use analog methods to create interference fringes. At radio wavelengths we can simply downconvert the signal so something more manageable and then calculate the antenna-antenna the interference.

Comment Re:The future of telescopes. (Score 1) 185

You still have to contend with the diffraction limit though, 100% efficiency be damned if you can't resolve anything. Also, CCDs are not as ineffecient as you are purporting them to be; they are as efficient as ~90% at some wavelengths (; therefore, getting 100% effeciency is not going to increase your signal as significantly as you seem to think.


Fine-Structure Constant Maybe Not So Constant 105

Kilrah_il writes "The fine-structure constant, a coupling constant characterizing the strength of the electromagnetic interaction, has been measured lately by scientists from the University of New South Wales in Sydney, Australia and has been found to change slightly in light sent from quasars in galaxies as far back as 12 billion years ago. Although the results look promising, caution is advised: 'This would be sensational if it were real, but I'm still not completely convinced that it's not simply systematic errors' in the data, comments cosmologist Max Tegmark of MIT. Craig Hogan of the University of Chicago and the Fermi National Accelerator Laboratory in Batavia, Ill., acknowledges that 'it's a competent team and a thorough analysis.' But because the work has such profound implications for physics and requires such a high level of precision measurements, 'it needs more proof before we'll believe it.'"

Space is to place as eternity is to time. -- Joseph Joubert