Red giant star Betelgeuse is shrinking

Orion’s red supergiant Betelgeuse has been steadily shrinking over the last 15 years.

Betelgeuse is so big that if placed in our Solar System it would extend to the orbit of Jupiter. But thanks to long term monitoring by Berkeley’s Infrared Spatial Interferometer (ISI) at Mt Wilson, measurements of the star’s diameter reveal the giant to be shrinking. Over the last 15 years, the star has shrunk by more than 15 percent, equivalent to the same diameter as the orbit of Venus.

Despite its diminished size however, there is no evidence to suggest that the star is dimming. But we do not know why the star is shrinking.

Since the star’s size depends on the wavelength of light used to measure it, it is difficult to compare measurements. Tenuous gas in the outer regions of the star emits light as well as absorbs it, which presents a challenge in determining the edge of the star.

Cosmic blobs and Galaxies

Cosmic blobs are immense reservoirs of hydrogen gas located in the early Universe. Black holes and star formation have been observed in cosmic blobs.

The glow of cosmic blobs in optical light had remained a mystery for the astronomers but with the help of telescopes such as Chandra X-ray Observatory,Spitzer Space Telescope and Hubble they have found that the source of power is coming from growing supermassive black holes and from newly forming stars.

Endeavour arrives at Space Station

Endeavour has arrived at the International Space Station for its construction mission that will install an external science deck to complete Japan's Kibo facilities, pre-stage critical spare parts for the outpost and replace aging batteries in the power grid.

Cosmic rays accelerated by exploded stars

Using ESO’s Very Large Telescope and NASA’s Chandra X-ray Observatory, astronomers have shown that cosmic rays from the Milky Way are very efficiently accelerated in the remnants of exploded stars.

Cosmic rays are extremely energetic particles – mostly protons – moving at close to the speed of light. They originate from outside our Solar System and are constantly bombarding the Earth’s atmosphere at a rate of some 100,000 per square metre per second.

Earth gravity and solar eclipse

A team of Chinese scientists is planning to conduct a once-in-a-century experiment on July 22, the day of the total solar eclipse, which would test the controversial theory that gravity drops slightly during a total eclipse.

According to a report in New Scientist, geophysicists from the Chinese Academy of Sciences are preparing an unprecedented array of highly sensitive instruments at six sites across the country to take gravity readings during the total eclipse due to pass over southern China on July 22.

The results, which will be analyzed in the coming months, could confirm once and for all that anomalous fluctuations observed during past eclipses are real.

The first sign that gravity fluctuates during an eclipse was in 1954, when French economist and physicist Maurice Allais noticed erratic behaviour in a swinging pendulum when an eclipse passed over Paris.

Pendulums typically swing back and forth as a result of gravity and the rotation of the Earth. At the start of the eclipse, however, the pendulum's swing direction shifted violently, suggesting a sudden change in gravitational pull.

In the run up to July's eclipse, Chinese researchers have prepared eight gravimeters and two pendulums spread across six monitoring sites.

At over five minutes, the event will be the longest total solar eclipse predicted for this century.

Shuttle Endeavour finally launched

Shuttle Endeavour finally roared to life and blasted off Wednesday on its sixth try, rocketing away through a hazy sky toward a Friday rendezvous with the International Space Station from Kennedy Space Center.

Multiple pieces of foam insulation fell from the ship's external tank during the early moments of flight, but it was not immediately clear whether the shuttle's fragile heat shield suffered any significant damage.

With commander Mark Polansky and pilot Douglas Hurley at the controls, Endeavour's three main engines ignited in staggered sequence and throttled up to full thrust, followed seconds later by ignition of the shuttle's twin solid-fuel boosters at 6:03:10 p.m. EDT.

President Obama hails successful Hubble repair

President Barack Obama called the crew of the shuttle Atlantis late Wednesday and congratulated the astronauts on the successful overhaul of the Hubble Space Telescope. He also promised to name a new NASA administrator soon, although he provided no clues as to who might get the nod.