Tag Archives: Radio Astronomy

Where Can I Find Fluxes for Strong Radio Galaxies?

Question: I am trying to calibrate New Horizons radiometry data and need flux of strong radio sources (Cas A, Cyg A, Tau A, and Vir A) at 7182 MHz.  Is there a good catalog of this basic information (flux at … Continue reading

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How Do You Distinguish Between People-Made Signals and Those From Space?

Question: You have loads of terrestrial interference, so how do you know the signals you receive are extra terrestrial? — Ariane Answer: The radio signals that we generate ourselves, such as by radar or radio communications, have a specific frequency … Continue reading

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Radio Caustics and Cusps in the Earth’s Ionosphere

Question: Hi! My question is about ionospheric caustics (IC). In dynamic spectra of several radio telescopes during daily solar observations there are unusual patterns. They are not identified with well-known solar radio bursts. I found that Bruny Island Radio Spectrometer … Continue reading

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How to Turn an Old Satellite Dish into a Radio Telescope

Question: I am a high school teacher and three of my students are trying to build a radio telescope with an eight foot satellite dish. What would your recommend?  — John Answer: Great student project!  There are quite a few … Continue reading

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What Does the VLA See or Hear?

Question: What do the VLAs actually “see” or “hear?” A recent report states Apollo 10 astronauts “heard” strange music in their radio systems on the dark side of the moon, where they were isolated from the interference produced on Earth. … Continue reading

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Can Radio Waves be Focused Like Visible Light?

Question: A visit to your Very Large Array prompted the question, “Can we focus radio waves much as we can focus visible light and lasers?” The question is important if aliens try to send us a radio message. If their … Continue reading

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How Did Karl Jansky Measure Galactic Radio Emission at 20.5 MHz When the Earth’s Ionosphere Reflects Radio Waves at This Frequency?

Question: If 20MHz waves are ‘bounced’ by the ionosphere, how is it that Karl Jansky detected 20.5MHz waves coming from the galactic centre in 1932?  Also, what sort of receiver would he have used?  — Brendan Answer: I had to … Continue reading

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Is There a Place Where One Can See Daily Radio Images of the Sun?

Question: Is there a place that posts daily images of the Sun in a radio frequency, perhaps 21 cm, something like SOHO does for shorter wavelengths?  — Donna Answer: Unfortunately, I am not aware of a source for regular radio … Continue reading

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Availability of VLA Measurements of M87?

Question: I am contacting you on behalf of the MAGIC collaboration. I was wondering whether you took with VLA any further data on M87. We are trying to get an MWL coverage for our observation period spanning from 2012 to … Continue reading

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Tatoo Me with the VLA

Question: Hi.  Would you do me a favor to send to me through email the old aerial view graphic of VLA? It is like the Mercedes Benz logo without the circle, with a small rectangular at the intersection of the … Continue reading

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