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Hint of 150 MHz radio emission from the Neptune-mass extrasolar transiting planet HAT-P-11b
Next Big Future ^ | 2/24/2013 | Brian Wang

Posted on 02/25/2013 10:34:07 AM PST by Red Badger

ince the radio-frequency emission from planets is expected to be strongly influenced by their interaction with the magnetic field and corona of the host star, the physics of this process can be effectively constrained by making sensitive measurements of the planetary radio emission.

Up to now, however, numerous searches for radio emission from extrasolar planets at radio wavelengths have only yielded negative results. Here we report deep radio observations of the nearby Neptune-mass extrasolar transiting planet HAT-P-11b at 150 MHz, using the Giant Meterwave Radio Telescope (GMRT).

On July 16, 2009, we detected a 3σ emission whose light curve is consistent with an eclipse when the planet passed behind the star. This emission is at a position 14′′ from the transiting exoplanet’s coordinates; thus, with a synthetized beam of FWHM∼16′′, the position uncertainty of this weak radio signal encompasses the location of HAT-P-11. We estimate a 5% false positive probability that the observed radio light curve mimics the planet’s eclipse light curve. If the faint signature is indeed a radio eclipse event associated with the planet, then its flux would be 3.87 mJy±1.29 mJy at 150 MHz. However, our equally sensitive repeat observations of the system on November 17, 2010 did not detect a significant signal in the radio light curve near the same position. This lack of confirmation leaves us with the possibility of either a variable planetary emission, or a chance occurrence of a false positive.

Although we are not able to draw a definitive conclusion on 150 MHz radio emission from HAT-P-11 b, at the very least the hint of radio detection presented here identifies HAT-P-11 b as a prime candidate for many follow-up observations in the near future. The priority is to try to confirm the present tentative detection, via re-observation with GMRT at 150 MHz and/or new observations with LOFAR in the 30-250 MHz range (providing a 1-100 mJy sensitivity depending on the observation parameters used; van Haarlem et al., submitted, 2013) and UTR-2 in the 10-30 MHz range (providing a sensitivity of ∼100 mJy; Ryabov et al. 2004). The observed spectral range can also be extended toward shorter wavelengths using GMRT, with even higher sensitivities of ∼1 mJy at 240 MHz and ∼50 µJy at 614 MHz (e.g., Lecavelier des Etangs et al. 2009). Observations over a broad range of frequencies will, with any luck, allow confirmation of the existence of the emission and better constraints on the planetary magnetic field strength and determination of the radio spectral index.

The future observations should also be distributed at multiple epochs and at different orbital phases of the planet to characterize the suspected variability of the radio emission in terms of duty cycle, as well as the radio emission as a function of the star-planet angle and the emission directivity (CMI produces narrowly beamed radio emission). In this context, Hess and Zarka (2011) have analyzed all the observables that could be derived from a broadband dynamic spectrum with a sufficient signal-tonoise ratio.

In the long term, it should be possible to investigate if the radio emission from extrasolar planetary systems correlates with the stellar spot activity. In this context, HAT-P-11 represents the target of choice because the Kepler mission has recently demonstrated the possibility of following the spot activity and perhap even of drawing the butterfly diagram of surface spots for this star.

Radio observations of different types of exoplanets are also crucial for comparative exoplanetology. For instance, observations of the other transiting hot-Neptune GJ436 b (Gillon et al. 2007) will allow comparison with a planet similar in mass but orbiting an M-dwarf star which is half the mass and radius of HAT-P-11 and known to have a strong Far-UV and Lyman-αoutput (Ehrenreich et al. 2010). With a 6.55 Earth mass, the nearby exoplanet GJ1214 b should also provide an opportunity to undertake search for radio emission from a water-rich lower mass super-Earth planet (Charbonneau et al. 2009; D´esert et al. 2011). In the near future, more sensitive observations at even lower frequencies will become feasible with the LOFAR observatory, providing a great boost to exoplanetary research.


TOPICS: Culture/Society
KEYWORDS: amateurradio; astronomy; exoplanet; ham; hatp11b; radio; space; xplanets
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Are they trying to send us a message?

Sounds like it........

http://en.wikipedia.org/wiki/HAT-P-11b

1 posted on 02/25/2013 10:34:13 AM PST by Red Badger
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To: SunkenCiv; KevinDavis

ET Phone home Ping!..........


2 posted on 02/25/2013 10:35:40 AM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: Red Badger

Pretty dumb aliens using VHF for this.


3 posted on 02/25/2013 10:41:00 AM PST by bkepley
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To: bkepley

Their Algore hasn’t invented their Internet yet.............


4 posted on 02/25/2013 10:42:46 AM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: Red Badger

Well, what sort of modulation are they using?


5 posted on 02/25/2013 10:44:09 AM PST by doorgunner69
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To: bkepley

Maybe they are transmitting TV reruns of Lost In Space........


6 posted on 02/25/2013 10:45:12 AM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: doorgunner69

AM........Alien Modulation, of course!..........


7 posted on 02/25/2013 10:46:46 AM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: Red Badger

"...of course it could be a bounce from the illudium Q-36 explosive space modulator. Where was the kaboom?"

8 posted on 02/25/2013 10:47:10 AM PST by Doogle (USAF.68-73..8th TFW Ubon Thailand..never store a threat you should have eliminated))
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To: Red Badger

“Hint of 150 MHz radio emission from the Neptune-mass extrasolar transiting planet HAT-P-11b”

http://www.johnspeedie.com/healy/saywhat.wav


9 posted on 02/25/2013 10:48:16 AM PST by BenLurkin (This is not a statement of fact. It is either opinion or satire; or both)
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To: bkepley
Maybe they think we are the dumb ones.
10 posted on 02/25/2013 10:49:22 AM PST by BenLurkin (This is not a statement of fact. It is either opinion or satire; or both)
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To: Doogle

This planet is located approximately 122 light-years away............it’s gonna take a while..........


11 posted on 02/25/2013 10:49:57 AM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: Doogle

It’s a message from the aliens, “Send More Chuck Berry.”


12 posted on 02/25/2013 10:50:01 AM PST by dfwgator
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To: BenLurkin

They want more Casey Kasem top 40 oldies countdowns!


13 posted on 02/25/2013 10:53:25 AM PST by Conserev1 ("Still Clinging to my Bible and my Weapon")
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To: Red Badger

>This planet is located approximately 122 light-years away.

Well I take it back then. If they were using VHF 122 years ago that’s not too shabby.


14 posted on 02/25/2013 10:54:20 AM PST by bkepley
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To: Doogle
Maybe it's an SOS....

15 posted on 02/25/2013 10:54:50 AM PST by BenLurkin (This is not a statement of fact. It is either opinion or satire; or both)
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To: Red Badger

Not a message, but rather, natural emissions. Stars generate HUGE magnetic fields. Planets orbiting and spinning within these fields disrupt them, and can produce radio waves as a result. Analysis of these emissions can tell astronomers more about the exoplanet. It is yet another clever technique to tease out info from these staggeringly distant objects.


16 posted on 02/25/2013 11:00:56 AM PST by Rebel_Ace (Tags?!? Tags?!? We don' neeeed no stinkin' Tags!)
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To: bkepley

Well, VHF communications would put them at the techno level of approximately 1940’s to 1960’s, 122 years ago, so they would be maybe 50 to 100 tears ahead of us.........


17 posted on 02/25/2013 11:01:51 AM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: bkepley

tears = years.......


18 posted on 02/25/2013 11:02:53 AM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: bkepley

Probably answering Tesla.


19 posted on 02/25/2013 11:04:42 AM PST by Dr. Bogus Pachysandra ( Ya can't pick up a turd by the clean end!)
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To: Rebel_Ace

20 posted on 02/25/2013 11:04:51 AM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: bkepley
Whatever you do, don't answer the phone!

(Ask the Inca and the Iroquois about that.)

21 posted on 02/25/2013 11:05:23 AM PST by Aevery_Freeman (They say "Right Wing" but they mean "Wrong Wing"!)
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To: Red Badger

But he smoked stuff in Tievman.


22 posted on 02/25/2013 11:07:47 AM PST by onedoug
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To: Red Badger
tears = years.......

Very profound, but dont you really mean years=tears?

I guess the "=" is bi-diretional though

23 posted on 02/25/2013 11:08:10 AM PST by beebuster2000
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To: beebuster2000

Symmetric Property of Equality:

If A = B, then B = A.


24 posted on 02/25/2013 11:11:10 AM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: Rebel_Ace
Jupiter emits RF in the 10 meter range.

/johnny

25 posted on 02/25/2013 11:12:29 AM PST by JRandomFreeper (Gone Galt)
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To: Red Badger

You’re listening to Quisp and the Morning Zoo here on Neptune’s Big 150 FM.


26 posted on 02/25/2013 11:12:36 AM PST by Buckeye McFrog
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To: Red Badger

So is the VHF repeater on Neptune? What’s the offset? Let me get out my Yagi and shoot for it.

CQ CQ...


27 posted on 02/25/2013 11:12:41 AM PST by struggle (http://killthegovernment.wordpress.com/)
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To: Dr. Bogus Pachysandra

28 posted on 02/25/2013 11:13:08 AM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: Red Badger

Send Jodi Foster.


29 posted on 02/25/2013 11:13:54 AM PST by massgopguy (I owe everything to George Bailey)
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To: Buckeye McFrog

....Asteroid impact on Interstellar 12934 has traffic backed up for light years..............


30 posted on 02/25/2013 11:14:24 AM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: struggle
Heck, I'd be happy if 6 meters would upen up.

/johnny

31 posted on 02/25/2013 11:14:40 AM PST by JRandomFreeper (Gone Galt)
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To: JRandomFreeper

CB Jovians......


32 posted on 02/25/2013 11:15:36 AM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: Red Badger
Sending us a video of this guy:


33 posted on 02/25/2013 11:16:26 AM PST by Lockbar (Quality Factory Loaded Ammunition ------- The New Gold)
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To: massgopguy

That movie was nothing like the book...............


34 posted on 02/25/2013 11:17:49 AM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: Red Badger

Yes, it’s the ubiquitous ladder in the road on
runway 3 at the Cape. Travelers are urged to use
caution when landing.


35 posted on 02/25/2013 11:18:01 AM PST by tet68 ( " We would not die in that man's company, that fears his fellowship to die with us...." Henry V.)
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To: tet68

It’s probably a junk mail fax that translates to “Drink more Ovaltine”.


36 posted on 02/25/2013 11:23:10 AM PST by AppyPappy (If you aren't part of the solution, there is good money to be made prolonging the problem.)
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To: tet68

Exits 3417 thru 3556 to New Jersey are still closed for roadwork...........


37 posted on 02/25/2013 11:24:41 AM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: dfwgator

“We need more cowbell.”


38 posted on 02/25/2013 11:37:25 AM PST by Cowgirl of Justice
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To: Red Badger
This lack of confirmation leaves us with the possibility of either a variable planetary emission, or a chance occurrence of a false positive. "lack", "false positive"
39 posted on 02/25/2013 11:43:35 AM PST by edcoil (Half of every class gratuates at the bottom, they are now politicians.)
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To: doorgunner69

They’re playing their 45s at 47 rpm.
It brightens up the sound...


40 posted on 02/25/2013 11:45:01 AM PST by Eric in the Ozarks (NRA Life Member)
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To: Rebel_Ace; Red Badger

What I’m going to have to look up is the definition of a radio light curve. The term doesn’t make sense to me.


41 posted on 02/25/2013 11:50:17 AM PST by FreedomOfExpression
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To: Red Badger
I am from planet HAT-P-11b and you are spreading very false rumors. I take umbrage and will do something about it!

All your rumors are belong to us!

FMCDH(BITS)

42 posted on 02/25/2013 11:51:48 AM PST by nothingnew (I fear for my Republic due to marxist influence in our government. Open eyes/see)
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To: FreedomOfExpression

http://en.wikipedia.org/wiki/Light_curve


43 posted on 02/25/2013 12:15:17 PM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: FreedomOfExpression

Perhaps the writer meant to say, “radio/light curve”.........


44 posted on 02/25/2013 12:17:26 PM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: nothingnew
Alien: You wanna piece of me, punk?........
45 posted on 02/25/2013 12:20:31 PM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: Red Badger

Nope. The Honeymooners. What happens when we get the Gork IV equivalent of “Pow, to the moon?”


46 posted on 02/25/2013 12:21:39 PM PST by ModelBreaker
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To: nothingnew
Alien: You wanna piece of me, punk?.........
47 posted on 02/25/2013 12:25:50 PM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: ModelBreaker

Too far away for that. They might have overheard the War of the Worlds broadcast of 1938, though........


48 posted on 02/25/2013 12:27:46 PM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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To: Red Badger

Bump to read later.


49 posted on 02/25/2013 12:28:11 PM PST by techcor
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To: JRandomFreeper
http://en.wikipedia.org/wiki/6-meter_band As transceivers have become more available for the 6-meter band, it has quickly gained popularity. In many countries, including the United States, access is granted to entry-level license holders. Those without access to international HF frequencies often gain their first taste of true long-distance communications on the 6-meter band. Many of these operators develop a real affection for the challenge of the band, and often continue to devote much time to it, even when they gain access to the HF frequencies after upgrading their licenses.
50 posted on 02/25/2013 12:32:50 PM PST by Red Badger (Lincoln freed the slaves. Obama just got them ALL back......................)
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