: Weighing the Milky Way? Yes, we CAN!
Thu 11 Nov 2021; Over the past few weeks students of the MSc course Radio Astronomy made radio telescopes out of paint cans. They used these "telescopes" to actually measure the orbital velocity of hydrogen in our Milky Way. The faster it orbits, the heavier our galaxy must be to prevent the gas from flying away. Our Milky Way has a maximum rotational speed of approximately 220 km/s, which is fortunately what the paint can telescopes actually confirm! A measurement like this requires accurate calibration to determine the properties of antenna and electronics in isolation. We are grateful that Dutch Microwave Absorber Solutions (https://dmas.eu), based in nearby Zoeterwoude provided us with high tech microwave absorbing material free of charge (the anthracite-coloured spikes). This material is normally used in specialist laboratories for antenna-research, radar technology, and radio interference. Dutch Microwave Absorber Solutions is global market leader in sustainable, top-quality radio-absorbing materials and entirely "Made in NL".

Michiel Brentjens Dutch Microwave Absorber SolutionsPubl. Thu 11 Nov 2021