Questions about observation performed in the radio frequency range of the electromagnetic spectrum (between 10 MHz and 1GHz).

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14
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2answers
232 views

What are practical considerations for backyard radio-astronomy detection of black holes?

Evidently, direct observation of a black hole for an amateur astronomer, such as described for what professionals do in the question "How are black holes found?" would be nigh on impossible, so the ...
8
votes
3answers
527 views

Jupiter FM - What are practical and inexpensive ways for the amateur detection of signals from Jupiter, especially of the transit of her moons?

What modifications to a standard AM/FM or shortwave radio are needed in order to be able to detect radio-wave signals emitted from Jupiter? Would it be possible to detect the transit of the major ...
7
votes
3answers
167 views

Can impact craters on the moon act like giant radio telescopes?

Could large craters on the moon be used as reflective lenses for radio signals? Acting like a large radio telescope reflecting radio waves to a satellite positioned over the crater.
5
votes
2answers
188 views

Does the radio signal decay when it travels through the intergalactic space?

When you emit the radio signal it starts moving at the speed of light. Radio beam is diffusing with each kilometer the signal has traveled. To the nearby receiver the signal is strong. But if the ...
5
votes
2answers
161 views

What can we expect from the first accurate image of a black hole? (wich will be taken soon)

From recent news from the Max Planck Institute for Radio Astronomy: The European Research Council (ERC) has awarded 14 Million Euros to a team of European astrophysicists to construct the first ...
5
votes
1answer
46 views

Current limitations in radio-astronomical spectrometry analysis of local interstellar cloud's hyperfine structures

I've been trying to wrap my head around capabilities of current radio-astronomical spectrometry technology to isolate not too distant tenuous sources, say, chemical composition and density of the the ...
4
votes
1answer
76 views

Brightest Radio Source In the Universe

I would have assumed that the brightest radio source in the Universe is a quasar of some kind (perhaps 3C 273) given that the average pulsar has luminosity of $~10^{40} \text{Watts}$ and this is the ...
4
votes
1answer
239 views

What is the maximum transmission distance of the radio signal in the outer space which could still be understood?

I’ll put this question in a form of a physics problem: Transmitter at a point A sends a signal to a receiver at a point B. What is the longest distance in light years from points A to B for which ...
3
votes
1answer
86 views

What determines which frequency range a radio telescope has?

My simple understanding is that a parabolic dish focuses radio waves to a receiver. It is obvious that any parabola focuses visible light and heat, so I assume that it focuses all radio wavelengths ...
3
votes
1answer
81 views

Is there another explanation, apart from the doppler effect, for the redshift observed in distant galaxies?

On episode 10 of the original Cosmos TV series, Carl Sagan mentions that some scientist don't agree that the redshift observed in distant galaxies is evidence of the big bang, stating that probably ...
3
votes
1answer
15 views

2SB mixer in radio astronomy?

In literature about the instrumentation of radio astronomy, I frequently come across a type of mixer described as "2SB". I'm familiar with single-sideband (SSB) and double-sideband (DSB) mixers, but ...
2
votes
1answer
29 views

How LOFAR pass through the ionosphere?

The LOFAR project open a new window in the universe's study because it allows to receive low frequences of the universe that we could not get because of the ionosphere. But I'm wondering how can ...
2
votes
2answers
41 views

What is meant by Electronic Beam Steering and how is it achieved?

I recently came across an article about the Murchison Wide Field Array which said directivity is achieved by Electronic Beam Steering and not by Mechanical methods. It would be helpful if someone can ...
2
votes
1answer
21 views

Do planetary radio frequency change upon alignments?

If Neptune would align Uranus, would the radio frequency perceived on Earth increase? Are the radio antennas on NM capable of getting the 2 different radio frequencies feom both planets or would they ...
2
votes
0answers
47 views

Can astronomical radio sources be used as a verifiable randomness beacon?

A randomness beacon is a source of random data that is broadcast to multiple parties. Users listening to the beacon receive the same sequence of random strings and no one can predict the values in ...
1
vote
1answer
29 views

Telescope in Sun's gravity lens focus - pointing, gain, distortions

A telescope located in the gravitational focus of the Sun can use the Sun as a magnifying lens. The focus begins 550 AU away, but maybe a 700 or 1000 AU distance is needed to get rid of disturbances ...
1
vote
0answers
23 views

What is frequency range?

Using the NED, you can search via frequency range corresponding to the selected pass band filter. I'm a beginner here and don't really understand. Here's the quote: NOTES: Objects with ...