April 21, 2014

27.04.11: Detecting “Exo-Aurorae.”

Saturian aurora seen in the infrared via the Cassini spacecraft. (Credit: NASA/JPL).

Planetary Scientists may soon have a new technique in their arsenal in the hunt for exo-solar planets. Current tried-and-true methods involve measuring tiny radial velocity shifts, catching a gravitational lensing event, or watching and measuring a tiny dip in brightness as a planet transits its host star. [Read more...]

27.04.11: MeerKAT & the Bid for SKA.

Artist’s impression of a SKA offset Gregorian dish. (Credit: Swinburne Astronomy Productions on a Creative Commons 3.0 license).

African radio astronomers are taking an innovative approach to a bid in hosting a unique proposal. The idea is known as the Square Kilometer Array, a radio observatory that will employ hundreds of dishes over a large area to scan and survey the radio sky in unprecedented detail. Much like the Allen Telescope Array being built in California, SKA’s strategy is to use the technique known as radio interferometry and go for many small dishes linked together rather than one large single antenna.

[Read more...]

02.11.09:The Low-Down on LOFAR.

The LOFAR station at Effelsberg, with the low-band masts in the foreground and the high band antenna in the background. (Credit: The Netherlands Institute for Radio Astronomy).

The LOFAR station at Effelsberg, with the low-band masts in the foreground and the high band antenna in the background. (Credit: The Netherlands Institute for Radio Astronomy).

European radio astronomers at the Netherlands Institute for Radio Astronomy (ASTRON) have recently opened a potentially new window on the universe with an exotic new instrument. Dubbed LOFAR, or the Low Frequency Array, this unique instrument will examine the sky at extremely low radio frequencies, with a low band of 30 to 78 MHz and a complimenting high band of 120 to 168 MHz. In contrast, the radio dish at the Arecibo Observatory in Puerto Rico operates in a range of 400-5000 MHz. We’re talking very low frequencies, in a range not well understood. Three arrays currently centered on Exloo in the Netherlands saw first “radio light” earlier this year, examining the powerful radio source Cygnus A, a suspected black hole candidate. As computer power increases, scientists hope to add arrays across Europe from Britain to the Ukraine to increase the resolution of the array. The low gain antenna masts are simple and cheap to construct, and are basic omni-directional dipole antennas utilizing a synthetic aperture. LOFAR will map events at low radio frequencies, from ionization in the Earth’s atmosphere caused by gamma-ray bursts to corneal mass ejections on the Sun to re-ionization of neutral hydrogen in the primordial universe. And that’s not to mention any surreptitious discoveries that always seem to crop up when a new portion of the electromagnetic spectrum gets analyzed… perhaps some ultra-advanced race communicates via low frequency black hole resonances? I seem to remember a plot in Arthur C. Clarke’s Imperial Earth that involved intelligent aliens and low frequency waves… watch for LOFAR “antenna farms” cropping up along the European country-side soon!