For the past year I have been the newsletter editor for UBC Astronomy Club. I was told I shouldn't have to spend more than an hour or two on each, but I always end up spending DAYS... I guess I'm just slow... Of course I'd want to help more people to be informed about what's happening in astronomy, but damn can there be more work!? Now that I've been there and done that, I'm just glad I don't have to write another one... Anyways, here's the last edition of the year (my sweat and blood):
Fate of Hubble PendingThe Hubble Space Telescope has just celebrated its 15-year anniversary. However, its fate is uncertain. A manned maintenance of the telescope was scheduled for late 2007 or 2008, but after the Columbia shuttle accident in 2003 and President Bush’s budget cut, the former NASA Administrator Sean O’Keefe had cancelled the mission in late 2004. A robotic mission to service the Hubble had been proposed earlier, but it was later determined to be too risky and costly, and the telescope was left to deorbit some time in 2013.
In a better turn of events, the new NASA Administrator Mike Griffin had announced that he will reconsider the deorbit decision in light of NASA’s plans to return to flight. The final decision will depend on the success of the new shuttle program.
The Hubble is estimated to function for two more years without service, and currently there is no replacement for Hubble's visible-light acuity even in planning. Its infrared capabilities won't be duplicated until at least early in the next decade when the James Webb telescope is expected to go up.
http://www.space.com/news/hoyer_hubble_050330.htmlhttp://www.space.com/news/050331_hubble_deorbit_plan.htmlhttp://www.space.com/news/griffin_hearing_050412.htmlhttp://www.space.com/news/050418_hubble_op-ed.htmlhttp://www.space.com/scienceastronomy/050422_hubble_anniv.htmlhttp://www.space.com/news/050429_hubble_griffin.htmlGravitational Lensing: Einstein’s GlassesAlbert Einstein is being remembered this year for the miracle year of 1905, during which he produced his amazing scientific outputs. One of his predictions was gravitational lensing, which is the result of gravity, or the curvature of space-time. When something passes near a massive object, its trajectory is deflected due to the curvature. This deflection applies to light as well, which could be focused or spread out, and galaxies can thus distort the background universe.
There are two types of gravitational lensing: strong and weak. Strong lensing is when the light from a quasar (a type of galaxy made extremely bright by hot gas falling onto a huge central black hole) is broken into multiple images, or when the shape of a galaxy is stretched out. Weak lensing, or cosmic shear, is the subtler magnification of quasars by galaxies, and it is what the Sloan Digital Sky Survey has been trying to observe for the past six years. The survey mapped out 13 million galaxies and 200,000 quasars in 10% of the sky, and used the large sample to statistically analyze the weak lensing that is occurring.
The results confirm the standard model of cosmology, and validated that the galaxies do not only contain their light emitting matters, but also dark matter, which contribute to their magnifying power. Gravitational lensing can therefore be used to map out how dark matter is distributed around galaxies.
http://www.space.com/scienceastronomy/050503_grav_lensing.htmlBlack Hole Birth PhotographedGamma ray bursts can be long-duration or short-duration. The long-duration gamma ray bursts last about a few seconds, and are associated with the formation of black holes when massive stars explode and collapse. Short-duration bursts that last only a fraction of a second, represent the formation of a black hole a few times the mass of the Sun and are accompanied by flashes of X-rays and visible light afterglow for a few minutes.
On May 9, astronomers photographed a short-duration gamma ray burst named GRB050509b. The visible-light afterglow is the first time an optical counterpart to a short-duration gamma-ray burst is ever detected. The gamma ray came from the formation of a black hole when two neutron stars merged 2.2 billion light-years away. Just before matter falls into the newly formed black hole, a high-energy process involving magnetism and near-light speed vents a superheated jet of gas out of the black hole at a significant fraction of light-speed and creates the gamma ray burst.
http://www.space.com/scienceastronomy/050509_blackhole_birth.htmlFirst Extrasolar Planet PictureIn April, a team of European astronomers claimed that they have produced the first photo of an extrasolar planet. The gaseous planet orbits a star similar to a young Sun, GQ Lupi, and is estimated to have twice the diameter of Jupiter. The temperature on the planet is about 2000 Kelvin, and water is detected in its atmosphere. The planet is three times farther from GQ Lupi than Neptune is from our Sun, and it takes 1,200 years to complete one orbit. It is not known why it is so far from the star. Some models show that it can be ten times the mass of Jupiter, and in that case it could be classified as a failed star known as a brown dwarf.
Last year another European team announced the first photograph of an extrasolar planet, but it is not clear whether the unusually large object (several times the mass of Jupiter) actually orbits a failed star, a brown dwarf.
http://www.space.com/scienceastronomy/050401_first_extrasolarplanet_pic.htmlThe eta Aquarid Meteor Shower May 5~6The annual eta Aquarid meteor is caused by debris left behind by Halley’s Comet. Earth passes through the debris stream every year and the meteoroids vaporize in the atmosphere. The meteors emanate from the constellation Aquarius, hence its name. The eta Aquarid can produce up to 5~10 meteors per hour and sometimes even dramatic Earth-grazing meteors due to the shower's low radiant on the horizon.
http://www.space.com/spacewatch/050504_meteor_shower.html
