User:Sadalsuud/sandbox

Circumstellar dynamics
In the late phase of stellar evolution, massive stars like Betelgeuse exhibit high rates of mass loss, possibly as much as 1 M☉ every 10,000 years, resulting in a complex circumstellar environment that is constantly in flux. In a 2009 paper, stellar mass loss was cited as the "key to understanding the evolution of the universe from the earliest cosmological times to the current epoch, and of planet formation and the formation of life itself. However, the physical mechanism is not well understood. When Schwarzschild first proposed his theory of huge convection cells, he argued it was the likely cause of mass loss in evolved supergiants like Betelgeuse. Recent work has corroborated this hypothesis, yet there are still uncertainties about the structure of their convection, the mechanism of their mass loss, the way dust forms in their extended atmosphere, and the conditions which precipitate their dramatic finale as a type II supernova. In 2001, Graham Harper estimated a stellar wind at 0.03 M☉ every 10,000 years, but research since 2009 has provided evidence of episodic mass loss making any total mass loss figure for Betelgeuse uncertain. Current observations suggest that a star like Betelgeuse may spend a portion of its lifetime as a red supergiant, but then cross back across the H-R diagram, pass once again through a brief yellow supergiant phase and then explode as a blue supergiant or Wolf-Rayet star.

In the late phase of stellar evolution, massive stars like Betelgeuse exhibit high rates of mass loss, possibly as much as 1 M☉ every 10,000 years, although realistic estimates are close to 0.03 M☉ over the same timeframe. This lost material forms a complex circumstellar environment that is constantly in flux. In a 2009 paper, stellar mass loss was cited as the "key to understanding the evolution of the universe from the earliest cosmological times to the current epoch, and of planet formation and the formation of life itself." However, the physical mechanism is not well understood. When Schwarzschild first proposed his theory of huge convection cells, he argued it was the likely cause of mass loss in evolved supergiants like Betelgeuse. Recent work has corroborated this hypothesis, yet there are still uncertainties about the structure of their convection, the mechanism of their mass loss, the way dust forms in their extended atmosphere, and the conditions which precipitate their dramatic finale as a type II supernova. Current observations suggest that a star like Betelgeuse may spend a portion of its lifetime as a red supergiant, but then cross back across the H-R diagram, pass once again through a brief yellow supergiant phase and then explode as a blue supergiant or Wolf-Rayet star.

Corona Australis Molecular Cloud
At a distance of 130 parsecs (~420ly), lies a dark nebula of gas and dust known as the Corona Australis molecular cloud, one of the nearest star formation regions from Earth. Sometimes referred to as the CrA Dark Cloud or simply the CrA Cloud, it hosts several reflection nebulae − NGC 6729, NGC 6726/6727, and IC 4812 being the most notable. The globular cluster known as NGC 6723, which in photographs appears close by, is actually 29,000ly away, and so not part of the region. The cloud is located in the constellation Corona Australis, close the border of Sagittarius, between Gamma CrA and Epsilon CrA and stretches roughly 8ly across.

The cloud is located at about 18% below the galactic plane and covers an angular area of 16.0° × 6.5° on the celestial sphere. Temperatures of the clouds range from 13–22 K, and there is a total of about 7,000 times the mass of the Sun in material. Over half of the mass of the complex is concentrated around ___________________, and this is the most active star-forming region. There are embedded infrared sources within the complex. A total of 425 infrared sources have been detected near the L1688 cloud. These are presumed to be young stellar objects, including 16 classified as protostars, 123 T Tauri stars with dense circumstellar disks, and 77 weaker T Tauri stars with thinner disks. The last two categories of stars have estimated ages ranging from 100,000 to a million years.

Known to exhibit significant extinction, as high as 45 magnitudes at visual wavelengths (AV∼45 mag), astronomers have now identified 55 distinct optical members within the CrA Cloud. At the core is the Coronet protostar cluster, a loose collection of about 30 young stars with a wide range of masses at various stages of evolution. Surrounding the cluster are a few late stage B stars, numerous Herbig–Haro objects, and several YSOs. At the opposite end of the mass spectrum, are two confirmed brown dwarfs along with seven more candidates. There are also many embedded infrared sources within the complex. The molecular cloud has been most widely surveyed in the infrared, X-rays, radio waves and in the millimeter continuum.

Source data
Chandra 2007 ESO 1109 ESO 1027 Hass 2008 Malin2010 Martín 2001 NASA 2010 Neuhäuser 2008 Peterson 2010 Wang 2004

In the north of the constellation is the Corona Australis Molecular Cloud, a dark molecular cloud with many embedded reflection nebulae, including NGC 6729, NGC 6726–7, and IC 4812. A star-forming region of around 7000 M☉, it contains Herbig–Haro objects, T Tauri stars with dense circumstellar disks, (protostars) and some very young stars. Located about 430 light years (130 parsecs) away, it is one of the closest star-forming regions to our solar system. The related NGC 6726 and 6727, along with unrelated NGC 6729, were first recorded by Johann Friedrich Julius Schmidt in 1865.

Currency Table
I believe that the recent redesign of this list is a step in the wrong direction. Here's why:
 * 1) The original "List of Market Opening Times" was focused on opening times. This new list has lost that focus, thereby making this list less useful.
 * 2) As a currency trader, the prior list was far more useful as it was sorted by opening times. With a 24-hour forex market and the fact that currency movements are highly correlated with the open and close of their respective equity and futures markets, the previous list
 * 3) By incorporating many new fields (1) Rank, 2) Economy 3) Headquarters 4) Market Capitalization 5) Year to date Trade Value), it has added a lot of superfluous information making the list unwieldy. Anyone who wanted that extra information could have easily retrieved it by clicking on the respective links for each stock exchange, or going to other lists.
 * 4) Sorting by Market Cap has nothing to do with opening times. It has to do with Market cap.
 * 5) The previous list incorporated many more markets and was growing