Questions tagged [radio]

Questions about the part of the electromagnetic spectrum with wave lengths longer than those of infrared radiation.

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What does the Sun “look like” below 100 MHz?

Radio2space.com's The Radio Sun says: At very low frequencies (below 0.1 GHz) and therefore at very long wavelengths (> 3m) the solar disk appears much bigger and brighter in the center, and its ...
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32 views

How can I determine the location of an object for one observer given the location for another?

I know an object exists at the location of the beam-pointing-center of a radio telescope. I know the elevation/azimuth of the beam pointing center, as well as it’s “location” in galactic coordinates. ...
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48 views

Has optical interferometry been done at radio frequency using heterodyning with a laser in a nonlinear material?

If one collects narrow band optical emission from a large telescope with frequency $f_1$ and mixes it in a nonlinear crystal with laser light of a nearby frequency $f_2$, it would produce two new ...
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1answer
110 views

How do we know that comets definitely mase and not just fluoresce?

Wikipedia's Astrophysical_maser#; comets mentions some anecdotes of notable masers associated with comets, and Maser emissions from comets begins: The 18-cm lines of the OH radical are the only ...
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1answer
103 views

Current delay for radio signals from the Mars InSight mission

I've been meaning to post it on the day when InSight landed but just got around to it now. When they broadcasted landing in real-time, it really wasn't in real-time because radio signals from Mars ...
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53 views

radio Jove pcb manufacturing file

Hello I want to make the radio Jove receiver whose design is available on NASA website. I don't want to purchase the receiver. I want to make it. but I don't have any knowledge about pcb design for ...
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106 views

What EM spectrum can stars be most cheaply observed using Remote Sensing during the day?

I would like to augment my GPS navigation with remote sensing of 'the sky.' I am looking for any astronomical body that can be perceived during the day. Maybe Pulsars emit something easily detected, ...
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1answer
135 views

What explains this puzzling radio signature from a fireball?

September 21, 2017 a bright fireball over Holland was reported by hundreds of people. Several all-sky cameras recorded it as well as a special radio beacon set up to capture radio signatures of ...
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2answers
434 views

How to calculate the integrated source flux density of a continuous source?

I'm working with data from radio surveys. My images are .fits files with BUNIT Jy/beam. I want to calculate the net flux from a continuous source (not point source). When I simply added all the ...
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452 views

Radiometer Equation for Flux Density

In Duncan and Lorimer's Handbook of Pulsar Astronomy, the equation for the flux density using a radio telescope is given as (for a top-hat function): $$S=\frac{\beta\,\mathrm{SNR}\, T_{sys}}{G\sqrt{...
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1answer
2k views

Why levels of radio contours maps are given in mJy/beam and what does it mean?

I know what a jansky is, but I don't understand what beam (in $\frac{1 Jy}{beam}$) is. If jansky is a unit of flux density, what kind of unit is $\frac{1 Jy}{beam}$?
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121 views

How do astronomers at SETI know if they received intelligent radio signals from other planets?

Do they expect to see wave modulations like the ones we use in our technology? what do they expect the waves to be like exactly?
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46 views

Detecting people on Proxima Cen b [duplicate]

Recently the news announced the discovery of a planet with characteristics similar in size to earth with the possibility for liquid water, 4.2 light years away. Now, if there was a civilisation of ...
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35 views

When does oscillation of interplanetary plasma occurs?

When does oscillation of interplanetary plasma occur? When and what are the reasons of the excitation of this plasma that makes it oscillate? Does it oscillate when is not excited? Can extremely ...
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1answer
316 views

Need help with the math in Python program to flag Jovian radio emissions

A few days ago I decided to take on the little project of converting a Qbasic program into Python (as a side project to my Radio Jove project), and I've managed to get it to run, but the math is ...
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256 views

Why does the Southern hemisphere seem to be short of radio telescopes? [closed]

In northern hemisphere, we have GBT, Arecibo, Parkes, Jodrell and VLA, while in southern hemisphere, only Australia has big radio telescopes. ALMA is in Chile, but it is in sub-mm. Is not ...