December 17, 2017

17.05.11: A “Cosmic Hand.”

Pulsar PSR B1509-58. (Credit: NASA/Chandra/CXC/SAO/P. Slane et al.)

“Wow…” Of course, this word often applies itself to the jaw-dropping field of astronomy… but the picture above really merits it. The image was snapped by the Chandra X-ray observatory. It displays pulsar PSR B1509-58 within a hand-shaped nebula located about 17,000 light years distant. [Read more...]

05.06.10: An Exoplanet Family Portrait.

Astronomers have recently accomplished another amazing first; the first images of an exoplanetary system taken with modest sized optics. But to perform this feat, several ground-breaking techniques had to first be pioneered. The target was HR 8799, a known exoplanetary system 120 light-years distant in the constellation Pegasus. The instrument was the Hale telescope just north of San Diego, and the team was out of NASA’s Jet Propulsion Laboratory in San Diego. Using a combination of coronagraph and masking the scope down to a diameter of 1.5 meters in diameter, the team was able to capture the above resulting image. The revolutionary “funnel coronagraph” was necessary to block the swamping light of the parent star; the masking was used to maximize the use of adaptive optics. The image was also taken in the infrared, an area of the spectrum in which the young hot planets generate the most energy. “The trick is to suppress the starlight without suppressing the planet light,” Stated JPL Astrophysicist Gene Serabyn. To give you a sense of scale, the three exoplanets pictured lay about 24 to 68 A.U. from their host sun; our own Jupiter orbits at a distance of about 5 A.U. Not only will the technique be capable of being scaled up for the observatory big guns, but it could also prove effective for space-based platforms, where a tension always exists between what astronomers would like to launch and payload limitations. Expect to see more exoplanet images via this method in the near future!

19.04.10- The Rise of WISE.

NASA has a new orbiting infrared eye on the universe. WISE, the Wide-field Infrared Space Explorer, is now open for business, and returning some fairly cool images. Launched out of Vandenberg AFB on December 12th of last year, the telescope is now parked in a sun-synchronous orbit at an inclination of 97.5° degrees. This allows WISE to keep its solar panels in a sunward orientation, while the telescope itself looks off at right angles to the Sun. This will also allow it to image continuous swaths of the sky as it orbits the Earth. WISE sports a 16” 40cm gold-plated mirror (talk about tricked out!) optimized for IR work and will conduct an all-sky survey with an unprecedented resolution across its 47 arc minute field of view. A successor to the IRAS and Spitzer, which ran out of coolant last year, WISE has an on-board supply on frozen hydrogen that should sustain it for a 10 month mission. To perform its mission, WISE must be cooled to -430° F, or about 15 Kelvins. It will also narrow in on possible targets for the James Webb Space telescope to be launched in 2014. JWST is much touted as the “successor to Hubble” but will actually be optimized for work in the infrared as well. IR work is virtually impossible to do from ground based telescopes, due to the absorption of IR wavelengths by water vapor in our atmosphere. Already, WISE has discovered comets, Near Earth objects, and opened a new window on nebulae and star formation… more discoveries to come!

04.04.10-Fermi: Einstein Still Rules.

We just can’t seem to get enough of NASA’s Fermi Gamma-Ray Space Telescope. The successor to the late Compton observatory that was de-orbited in 2002, Fermi has already pinpointed over 1,000 discrete gamma-ray sources, five times more than previously known. Now Fermi has also provided a rare test of Einstein’s theories of relativity. Relativity says that all electromagnetic waves (including highly energetic gamma-rays) travel through space at the same cosmic speed of 186,282 miles per second. Being a classical theory, however, what Einstein doesn’t do is meld gravity satisfactorily with the other three fundamental forces; electromagnetism and the strong and weak nuclear forces. Gravity stubbornly refuses to be unified, and such a goal has been the holy grail of physics for over the last half century. An alternative model of gravity at the microscopic scale would say that the nature of space-time is “frothy,” and a predicted effect should be a measureable drag induced on high energy photons. Recently, Fermi had a chance to put this to the test; on May 10th of last year, GRB 090510, a short gamma-ray burst 7.3 billion light years distant, was measured by Fermi’s Large Area Telescope. The verdict; gamma-ray photons varying a by a factor of a million times in energy arrived just nine-tenths of a second apart, far below what would be predicted by “frothy” space… that’s round one for Einstein!

Update: the Final Hubble Servicing Mission.

Mark your calendars; NASA is set to fly one final servicing mission to the Hubble Space Telescope! First launched in 1990, the Hubble Space Telescope forever altered our view of the heavens.

[Read more...]