Musings of a Babylon Lurker

Radio Astronomy and SETI

Monday, October 22nd, 2007 | astronomy, science, space | No Comments

On 11 october a new radio telescope started operation. The Allen Telescope Array (ATA) in Hat Creek, CA is planned to be extended to an array of 350 dish antennas with a diameter of 6m (20ft) The inauguration was done with the first 42 of these dishes.

The ATA is built to do simultaneous radio astronmical observations and SETI work.

More detail can be found at the website for the SETI institute ATA ppress release.

I am quite excited, since the data collected from the ATA is *much* more than from traditional single dish telescopes , and more than will come from the VLA (Very Large Array) – and for a cost much loser than for older (traditional) radio telescopes.

For more about SETI (Search for ExtraTerrestrial Intelligence), take a look at at the websites :

SETI Institute

SETI League

SETI@home

Pulsar Measurements – Radio Astronomy Podcast

Thursday, July 5th, 2007 | astronomy, podcast, science | 5 Comments

Just heard this on the podcast “Mountain Radio Astronomy”. Their podcast of 8 October 2005 was an interview with pulsar hunter Scott Ransom at the National Radio Astronomy Observatory in Charlottesville. Scott had – at the time of the interview – found about 30 millisecond pulsars in a globular star cluster called Terzan 5.

A pulsar is believed to be a quickly rotating neutron star, a supernova remnant, most of them rotating in less than a second. The pulsar has a rather small and directional radiating area that can only be registered when it is facing us.
A second type of even faster rotating pulsars – known as millisecond pulsars – rotating more than a 100 tomes per second, are found in globular star clusters.

The rotation period of the millisecond pulsars is extremely precise, approaching that of an atomic clock , and this means thatsome interesting measurements of pulsar orbits can be made.

About 20 minutes into the interview he talked about a measurement of a pulsar orbit with an accuracy that really surprised me.

The example here is the Hulse-Taylor star system two pulsars orbiting each other in an orbit smaller than the Sun.This can demonstrate Einstein’s general theory of relativity, the interaction between spacetime and gravitation and an indication of gravity waves.

One other of the pulsars, Terzan N is orbiting a massive companion in an almost exact circular orbit about the size of the Sun.there is a little eccentricity, that is difference in the long axis and the short axis of the orbit, is measured as 48 cm +/- 6 cm. Less than half a meter ! Measured at a distance of 20 000 light years. Mind blowing …

Science stranger than fiction …

Link to Mountain Radio Astronomy

Link to The podcast MP3 file