Today we were given a nice tour of the labs at ASTRON. They do not only radio instrumentation, but also optical and IR work. We got to see the LOFAR development as well as stuff for the SKA. They were in the middle of assembling “X-shooter” an instrument for the Very Large Telescope in Chile. See below for pictures!
Tuesday, 31 July 2007
Monday, 30 July 2007
The Jodcast – an astronomy podcast
I came across this while looking for interesting podcasts. Operated by Jordrell Bank (a well known radio astronomy center in the UK). It’s a monthy podcast in mp3 format that talks about various news in astronomy. The July episode has a guest talking about the Gemini telescopes – a pair of 8.1m telescopes in the Northern and Southern hemispheres.
ASTRON Summer Student Lectures
There is a small summer student lecture series at ASTRON which aims to expose the summer students the various aspects of radio astronomy. We had 5 lectures and I’ve posted my notes online. They were general overviews about the major topics including: H I (neutral hydrogen), the LOFAR radio telescope, Pulsars, and Masers. They notes contain mostly non-technical summaries of the respective topics. Enjoy!
Friday, 27 July 2007
Grote Reber
Yesterday I had the great opportunity to be present at a ceremony commemorating the first radio astronomer: Grote Reber. After his death in 2002 (just shy of his 91st birthday), his ashes have been sent to the major radio observatories around the world. The Dwingeloo Radio Observatory here at ASTRON is one of those locations.
As part of this ceremony, several of Grote Reber’s friends came and gave presentations on his life, including Dave Jauncey (from the Australia Telescope National Facility) and Ken Kellermann (from the National Radio Astronomy Observatory). Oddly enough, I’d never heard of Grote Reber before being invited to this ceremony, but after hearing the presentations, I learned how much he contributed to the area of astronomy in which I’m working.
After the presentations about Grote Reber, there was a short presentation about LOFAR, which will be operating in the low-frequency range in which Grote did most of his work. At the conclusion of this talk, we all went outside to the radio telescope where the plaque commemorating Grote and his ashes was unveiled.
It was a very nice ceremony and I am glad I was able to attend. If you have the opportunity to read more about Grote Reber, he was quite a scientist. He published around 70 scientific papers. While the number isn’t particularly impressive today, most of his papers were single author, which is impressive. Also, he published papers in ~30 journals, which is also impressive given most scientists today only publish papers in a few journals close to their main field.
EDIT (30 July 2007): A picture of the plaque unveiling is now online.
Tuesday, 24 July 2007
The JIVE Correlator
The correlator is a vital component of a radio interferometer. This piece of equipment (or more recently, software) compares the signals from pairs of telescopes, generating the data which is later used to make an image. The correlation has the added benefit of reducing noise (which is generally uncorrelated between telescopes).
Bob Campell of the Joint Institute for VLBI in Europe (JIVE) gave the summer students a tour of the JIVE correlator. Follow the link below to see the pictures and descriptions of what’s in each picture. Some of the descriptions give a bit of information about how a correlator works, but I hope to provide a more complete picture in the next mini-article about my research.
Monday, 23 July 2007
BBC NEWS | May looks to sky to complete PhD
BBC NEWS | Entertainment | May looks to sky to complete PhD
Guitarist Brian May is to spend two days studying the night sky in the Canary Islands as he completes the PhD he abandoned in 1971 to join Queen.
This week in “Astronomers who rock”…. 
Saturday, 21 July 2007
Cycling in Zwartewaterland
I spent today working on my fitness and enjoying the countryside of the Netherlands! I left the guesthouse at 9:10 and started riding. 6 hours and 20 mins later (including time for sightseeing) I returned to the guest house, having covered about 90km. I took roughly this route.
My first stop was the town of Steenwijk. It’s a good sized town and seems very nicely laid out. Near the central church is a sizeable pedestrian zone. As it was Saturday, there was a large public market going on. I stopped into a photo store and replenished my stock of black and white film, as I’ve already shot 3 rolls in the last few weeks. The shopkeeper commented that he hadn’t sold any film in a while but I was the second person that day to buy film!
Friday, 20 July 2007
Terraforming Mars
Can trees grow on Mars? – Space News – MSNBC.com
Scientists are using the pine-forested slopes of a Mexican volcano as a test bed to see if trees could grow on a heated-up Mars, part of a vision of making the chilly and barren red planet habitable for humans one day.
While terraforming has been used in science fiction for a long time, this article is about real research and ideas about making Mars a balmy 41F (up from -67F). This might enable trees to be grown on Mars, which would lead to a oxygenated environment suitable for human life (with jackets of course 
).
My Research: Radio Interferometry
The resolution of a telescope is determined by two factors: the wavelength of light being observed and the diameter of the telescope. A larger telescope allows you see smaller details and a shorter wavelength also allows you to see smaller details. Due to the fact that radio waves (which have wavelengths of a few centimeters to a meter) have a must longer wavelength than visible light (several hundred nanometers), a correspondinly larger telescope must be built. If you want the same resolution in radio waves as visible light, you need a radio dish that is about 10,000 times larger than your optical telescope!
Around the time radio wavelengths were first being studied in astronomy, the largest telescope were several meters across. Thus, you’d need a radio dish about 30km across! And optical telescopes have only gotten bigger since then..
Wednesday, 18 July 2007
Seeing the Milky Way Again
After another episode of bridge, which extended late into the night, I got involved in a conversation about the future of radio astronomy. Currently there are multiple “pathfinder” telescopes being built in preparation for the Square Kilometre Array (SKA), such as: LOFAR and the Mileura Wide-Field Array. As the “good old boys” of radio astronomy are not getting any younger, the astronomer leading the discussion (who’s been working in radio astronomy since the mid 1970s) noted there is a shortage of young people with the knowledge necessary to design and implement new radio instrumentation. I noticed this as well when I attended a meeting for the US SKA consortium… most of the insightful comments and suggestions came from the older crowd of radio astronomers. There was a lack of activity from the younger crowd (not a complete lack however).
It got me thinking about my future in astronomy. I have been mulling over getting involved in an instrumentation project during my PhD studies. One opportunity I might have is with ALMA as the operations center will be down the road from the Astronomy building at UVa. Getting in on the ground floor of an observatory and obtaining intimate knowledge with the workings of radio telescope would likely be a great advantage. Something I’ll have to keep considering….
After the interesting discussion, I cycled back to the guest house. Crossing the heath, I was treated to amazingly clear skies (for the Netherlands). This afforded an excellent view of the little dipper ahead of me and the milky way overhead. It was quite an awe-inspiring sight. It’s humbling to see the vastness of the galaxy and the Universe. But also very exciting to know that we can learn so much about it, and that I’m part of it.
