Tag Archives: Green Bank Telescope

Wired: The ngVLA and “Rebirth of Radio Astronomy”

The NRAO’s Very Large Array (VLA) in New Mexico is 40 years old.

(Source: WIRED)

IN THE EARLY 1930s, Bell Labs was experimenting with making wireless transatlantic calls. The communications goliath wanted to understand the static that might crackle across the ocean, so it asked an engineer named Karl Jansky to investigate its sources. He found three: nearby thunderstorms, distant thunderstorms, and a steady hiss, coming from … somewhere.

Jansky studied the hiss for a year, using a rudimentary antenna that looked like toppled scaffolding, before announcing its origin: The static was coming from the the galaxy itself. “Radio waves heard from remote space,” announced The New York Times in May 1933. “Sound like steam from a radiator after traveling 30,000 light-years.” Janksy had unwittingly spawned the field of radio astronomy.

Today, a replica of Jansky’s scope sits on the lawn in front of Green Bank Observatory, one of the four world-class public radio telescopes in the US. Along with the Very Large Array, Arecibo Observatory, and the Very Long Baseline Array (VLBA), it is the legacy of a boom time in federal investment in the field that began in earnest after World War II.

In the past several years, though, the National Science Foundation has backed away from three of those instruments. In 2012 the NSF published a review recommending that the foundation ramp down funding to Green Bank—just 11 years after it was finished—as well as the VLBA, which can resolve a penny from about 960 miles away. Three years later, the foundation asked Arecibo for management proposals that “involve a substantially reduced funding commitment from NSF.”

[S]upport for pure science in the US is always complicated, since it relies on the good graces of federal agencies and annual budgets. As funders balance building and operating new scopes with the old, while giving grants to the astronomers who actually use those instruments, something’s gotta give. And no matter what it is, the science will not be the same.

[…]THERE IS A new facility potentially on the horizon: The Next-Generation VLA (the VLA itself, while upgraded, is 40 years old). As currently envisioned, the ngVLA’s many antennas will together have 10 times the sensitivity and resolution as the VLA, at a wider range of frequencies. The primary array will have 214 18-meter antennas, spiraled across New Mexico, Texas, Arizona, and Mexico. Nineteen smaller ones will sit close to the center, and 30 18-meterers will constellate the continent.[…]

Read the full article at WIRED magazine.

Check out this video for more info about the ngVLA:

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Listening to Oumuamua via the Green Bank Telescope

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Many thanks to SWLing Post contributor, Ferruccio Manfieri, who writes:

I bother you to mention this uncommon radio listening project i’ve just found via The Guardian:

Green Bank telescope in West Virginia will listen for radio signals from ‘Oumuamua, an object from another solar system

Astronomers are to use one of the world’s largest telescopes to check a mysterious object that is speeding through the solar system for signs of alien technology.

The Green Bank telescope in West Virginia will listen for radio signals being broadcast from a cigar-shaped body which was first spotted in the solar system in October. The body arrived from interstellar space and reached a peak speed of 196,000 mph as it swept past the sun.

Scientists on the Breakthrough Listen project, which searches for evidence of alien civilisations, said the Green Bank telescope would monitor the object, named ‘Oumuamua, from Wednesday. The first phase of observations is expected to last 10 hours and will tune in to four different radio transmission bands.

“Most likely it is of natural origin, but because it is so peculiar, we would like to check if it has any sign of artificial origin, such as radio emissions,” said Avi Loeb, professor of astronomy at Harvard University and an adviser to the Breakthrough Listen project. “If we do detect a signal that appears artificial in origin, we’ll know immediately.”

The linked article says that “(…)Scientists on the Breakthrough Listen project, which searches for evidence of alien civilisations, said the Green Bank telescope would monitor the object, named ‘Oumuamua, from Wednesday. The first phase of observations is expected to last 10 hours and will tune in to four different radio transmission bands.”

From the website of the project (http://breakthroughinitiatives.org/initiative/1):

Breakthrough Listen is the largest ever scientific research program aimed at finding evidence of civilizations beyond Earth. The scope and power of the search are on an unprecedented scale:

The program includes a survey of the 1,000,000 closest stars to Earth. It scans the center of our galaxy and the entire galactic plane. Beyond the Milky Way, it listens for messages from the 100 closest galaxies to ours.

The instruments used are among the world’s most powerful. They are 50 times more sensitive than existing telescopes dedicated to the search for intelligence.
The radio surveys cover 10 times more of the sky than previous programs. They also cover at least 5 times more of the radio spectrum – and do it 100 times faster. They are sensitive enough to hear a common aircraft radar transmitting to us from any of the 1000 nearest stars.

In particular:

“Listen’s observation campaign will begin on Wednesday, December 13 at 3:00 pm ET. Using the Robert C. Byrd Green Bank Telescope, it will continue to observe ‘Oumuamua across four radio bands, from 1 to 12 GHz. Its first phase of observations will last a total of 10 hours, divided into four “epochs” based on the object’s period of rotation.”

I know it’s out of our common shortwave range and scope of interest, but as a radio listening enthusiast I’m fascinated by this visionary scientific enterprise.

Thank you, Ferruccio, for sharing this. Being a fan of radio astronomy, SETI, and weak signal DXing, of course I find this fascinating! Thanks for sharing!

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SDRs processing Fast Radio Bursts from distant universe

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The Green Bank Telescope (Source: NRAO)

Many thanks to SWLing Post contributor, Ed, who shares a link to the following article at Breakthrough Initiatives:

Green Bank Telescope observations of a dwarf galaxy three billion light years away reveal 15 bursts of radio emission. This is the first time bursts from this source have been seen at these frequencies.

San Francisco – August 29, 2017 – Breakthrough Listen – the initiative to find signs of intelligent life in the universe – has detected 15 fast radio bursts emanating from the mysterious “repeater” FRB 121102. Fast radio bursts, or FRBs, are brief, bright pulses of radio emission from distant galaxies. First detected with the Parkes Telescope in Australia, FRBs have now been seen by several radio telescopes around the world. FRB 121102 was discovered in 2012, on November 2nd (hence its name). In 2015, it was the first FRB seen to repeat, ruling out theories of the bursts’ origins that involved the catastrophic destruction of the progenitor (at least in this particular instance). And in 2016, the repeater was the first FRB to have its location pinpointed with sufficient precision to allow its host galaxy to be identified. It resides in a dwarf galaxy about 3 billion light years away from Earth.

Attempts to understand the mechanism that generates FRBs have made this galaxy a target of ongoing monitoring campaigns by instruments across the globe. Possible explanations for FRBs range from outbursts from rotating neutron stars with extremely strong magnetic fields, to more speculative ideas that they are directed energy sources used by extraterrestrial civilizations to power spacecraft.

Breakthrough Listen is a global astronomical initiative launched in 2015 by Internet investor and philanthropist Yuri Milner and cosmologist Stephen Hawking. As part of their program to observe nearby stars and galaxies for signatures of extraterrestrial technology, the Listen science team at UC Berkeley added FRB 121102 to their list of targets. In the early hours of Saturday, August 26, UC Berkeley Postdoctoral Researcher Dr. Vishal Gajjar observed the location of FRB 121102 using the Breakthrough Listen backend instrument at the Green Bank Telescope in West Virginia. The instrument accumulated 400 TB of data on the object over a five hour observation, observing the entire 4 to 8 GHz frequency band.[…]

Analysis by Dr. Gajjar and the Listen team revealed 15 new pulses from FRB 121102. As well as confirming that the source is in a newly active state, the high resolution of the data obtained by the Listen instrument will allow measurement of the properties of these mysterious bursts at a higher precision than ever possible before.

The observations also show for the first time that FRBs emit at higher frequencies (with the brightest emission occurring at around 7 GHz) than previously observed. The extraordinary capabilities of the Listen backend, which is able to record several gigahertz of bandwidth at a time, split into billions of individual channels, enable a new view of the frequency spectrum of FRBs, and should shed additional light on the processes giving rise to FRB emission.
When the recently-detected pulses left their host galaxy our entire Solar System was just 2 billion years old. […]

The new results are reported as an Astronomer’s Telegram at www.astronomerstelegram.org/?read=10675 and will be described in further detail in an upcoming scientific journal article.

Breakthrough Listen is a scientific program in search for evidence of technological life in the Universe. It aims to survey one million nearby stars, the entire galactic plane and 100 nearby galaxies at a wide range of radio and optical bands.[…]

The linked animation shows 14 of the 15 detected bursts in succession, illustrating their dispersed spectrum and extreme variability. Capturing this diverse set of bursts was made possible by the broad bandwidth that can be processed by the Breakthrough Listen backend at the Green Bank Telescope:

https://storage.googleapis.com/frb121102/FRB121102_Cband_GB.gif

Click here to read the full article at Breakthrough Initiatives.

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Will Green Bank soon become a little less radio quiet?

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(Source: BBC News via Richard Langley)

Disturbing the peace: Can America’s quietest town be saved?

There’s a town in West Virginia where there are tight restrictions on mobile signal, wifi and other parts of what most of us know as simply: modern life. It means Green Bank is a place unlike anywhere else in the world. But that could be set to change.

“Do you ever sit awake at night and wonder, what if?” I asked.

Mike Holstine’s eyes twinkled like the stars he had spent his life’s work observing.

“The universe is so huge,” he began.

“On the off chance we do get that hugely lucky signal, when we look in the right place, at the right frequency. When we get that… can you imagine what that’s going to do to humankind?”

Holstine is business manager at the Green Bank Observatory, the centrepiece of which is the colossal Green Bank Telescope. On a foggy Tuesday morning, I’m standing in the middle of it, looking up, feeling small.

Though the GBT has many research tasks, the one everyone talks about is the search for extra-terrestrial intelligence. The GBT listens out for signs of communication or activity by species that are not from Earth.

[…]Green Bank sits at the heart of the National Radio Quiet Zone, a 13,000 square mile (33,669 sq km) area where certain types of transmissions are restricted so as not to create interference to the variety of instruments set up in the hills – as well as the Green Bank Observatory, there is also Sugar Grove, a US intelligence agency outpost.

For those in the immediate vicinity of the GBT, the rules are more strict. Your mobile phone is useless here, you will not get a TV signal and you can’t have strong wi-fi? -?though they admit this is a losing battle. Modern life is winning, gradually. And newer wi-fi standards do not interfere with the same frequencies as before.[…]

Read the full article on the BBC News website.

Additionally, if you have access to the BBC iPlayer, click here to watch the Click episode featuring Green Bank.

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National Radio Quiet Zone featured in BBC Radio 4 series

Living in a National Radio Quiet Zone

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The Green Bank Telescope: An impressive parabolic dish covering 2.3 acres, the GBT has the largest collecting area of any fully-steerable telescope in the world. (Photo: R. Creager, NRAO/AUI/NSF)

Many thanks to SWLing Post reader, Paul, who shares this National Geographic video about Green Bank, West Virginia, USA–home of the National Radio Astronomy Observatory (NRAO):

My wife and I took a camping trip to Green Bank in the late 1990s when the massive Green Bank Telescope was about 80% complete. The NRAO site is inspiring and you (of course) will find no better place on the east coast for RF quiet conditions.

The staff at the NRAO give daily tours throughout the year–click here to view the schedule and costs.

I’m overdue for another visit.

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