The Accelerating Universe and Dark Energy Might Be Illusions
The uncertainty of science: A new theory posits that the accelerating universe and dark energy might be illusions caused by motion of our galaxy through space.
Tag: astronomy
A second large satellite will rain debris down in October
Even if UARS misses you today, don’t relax! A second large satellite, the 2.4 ton ROSAT X-Ray space telescope, is going to rain debris down late in October or early November.
On its ROSAT website, DLR estimates that “up to 30 individual debris items with a total mass of up to 1.6 tonnes might reach the surface of the Earth. The X-ray optical system, with its mirrors and a mechanical support structure made of carbon-fibre reinforced composite – or at least a part of it – could be the heaviest single component to reach the ground.”
Astronomers argue about the legitimacy of the first exoplanet to be directly imaged
Astronomers question the legitimacy of the first exoplanet to be directly imaged.
WISE telescope raises questions about asteroid that is thought to have killed dinosaurs
The WISE space telescope has raised questions about source of the asteroid believed to have killed the dinosaurs.
New exoplanets make astronomers long for a telescope to see them
The plethora of new exoplanet discoveries has astronomers longing for a telescope that can see them up close.
Astronomers need either a giant space telescope equipped with a device for blocking starlight, or an interferometer, consisting of several telescopes flying in formation. NASA did develop a proposal for such a space telescope, called Terrestrial Planet Finder, and the European Space Agency hoped to fly a similar mission called Darwin. But budgetary constraints have left both missions in limbo, unlikely to advance to the front of either agency’s queue until well into the next decade. At the conference, Traub raised the issue. “People are not thinking deeply about the distant future. People are wrapped up with what they’re doing right now,” he says. “Clearly, I’m concerned.”
Webb Telescope budget continues to grow
Bad news for astronomers: The budget for the James Webb Space Telescope continues to swell.
A Yellow Supergiant Progenitor of a Massive Star Supernova in M51
The uncertainty of science: Astronomers have determined that the star that went supernova in the Whirlpool Galaxy (M51) in June — making it the nearest supernova in 25 years — was a yellow supergiant star, not an aging red supergiant as predicted by theory. From the preprint paper:
Despite the canonical prediction that Type II supernovae arise from red supergiants, there is mounting evidence that some stars explode as yellow supergiants. A handful of Type II supernovae have been observed to arise from yellow supergiants: supernovae 1993J, 2008cn, and 2009kr. The locations of the progenitors on the Hertzsprung-Russell diagram shows clearly that these stars are not located on the predicted end points for single star stellar evolution tracks. In addition, despite arising from supposedly similar yellow supergiant progenitors, these supernovae display a wide range of properties.
The Hertzsprung-Russell diagram is a graph mapping the color of stars against their luminosity. Because color and brightness change as the star evolves over time, the graph is used by astronomers to track the birth, growth, and death of stars. That these yellow supergiants don’t appear to be at “the predicted end points for single star evolution” on the diagram is a serious problem for the theorists who have tried to explain what causes this particular type of supernova.
Which also means astronomers are still unable to tell us what stars in the sky are most likely to go supernova in the future.
Update on the repairs to the Subaru Telescope
The Subaru Telescope team has posted an update on its repair effort following a July 2nd coolant leak.
A Smartphone ap to weigh galaxies
Want to known how much a galaxy weighs? There is now an Android smartphone application, GalMass, for calculating it!
A planet with two suns
Has Dark Matter been detected?
A slew of exoplanets
Using two European-built ground-based telescopes in Chile, astronomers have announced today the discovery of 50 new exoplanets, 16 of which are considered super Earths, one of which is in the habitable zone of its star. You can read the preprint of their research paper here [pdf].
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