Planet detection by natural laser emission
These last years, the search for extrasolar planets has been successful. To date, the astronomers have detected more than 300 extrasolar planets. Among these 300 planets, only ten have been discovered by their own light.
There is perhaps a phenomenon which could facilitate this search for extrasolar planets.
The astronomer Michael Mumma and his team have discovered in 1981 (*) a natural laser emission produced by the Martian upper atmosphere. This very fine emission ray centered on 10,33 µm is due to carbon dioxide, majority component of the Martian atmosphere. This natural laser emission has been not only confirmed by other teams but another natural laser has been discovered in the Venusian upper atmosphere.
In consequence of these discoveries, one can suppose that this phenomenon of stimulated emission generated by a planetary atmosphere is frequent.
This phenomenon of stimulated emission could be used for the search for extrasolar planets. The direct detection of an extrasolar planet conflicts, with current technology, with a considerable obstacle: the difference of brightness between planet and its star companion. If the studied planet has an atmosphere and if this one presents a stimulated emission, the brightness of planet in the emission ray could be amplified considerably. To benefit from this emission, it would be necessary to detect very thin rays. With this condition, the ratio of brightness between star and planet could become more favorable for a direct detection.
A first step in the use of this phenomenon could be the checking of its presence on the extrasolar planets already discovered.
Several ray masers would deserve a detailed attention: the ray at 23.7 GHz emitted by molecule NH3 and the rays at 22 GHz and 1.66 GHz emitted by molecule H2O and radical OH. As the stars emit little in this part of electromagnetic spectrum, one can hope for a ratio of brightness more favorable for the planet detection. The ray maser of ammonia could be a good marker for gas giant planets. The masers of water and radical hydroxyl would be good indices for planets similar to Earth.
(*): "Discovery of Natural Gain Amplification in the 10-Micrometer Carbon Dioxide Laser Bands one Mars: A Natural Laser"; MICHAEL J MUMMA, DAVID BUHL, GORDON CHIN, DRAKE DEMING, FRED ESPENAK, THEODOR KOSTIUK, and DAVID ZIPOY; Science, 3 April 1981, Vol. 212, No 4490, pp. 45 – 49.
QUOTE (daumic+May 6 2009, 10:29 PM)
A first step in the use of this phenomenon could be the checking of its presence on the extrasolar planets already discovered.
Several ray masers would deserve a detailed attention: the ray at 23.7 GHz emitted by molecule NH3 and the rays at 22 GHz and 1.66 GHz emitted by molecule H2O and radical OH. As the stars emit little in this part of electromagnetic spectrum, one can hope for a ratio of brightness more favorable for the planet detection. The ray maser of ammonia could be a good marker for gas giant planets. The masers of water and radical hydroxyl would be good indices for planets similar to Earth.
(*): "Discovery of Natural Gain Amplification in the 10-Micrometer Carbon Dioxide Laser Bands one Mars: A Natural Laser"; MICHAEL J MUMMA, DAVID BUHL, GORDON CHIN, DRAKE DEMING, FRED ESPENAK, THEODOR KOSTIUK, and DAVID ZIPOY; Science, 3 April 1981, Vol. 212, No 4490, pp. 45 – 49.
Good thinking:
However, just to inform you...stellar sources of OH microwave MASER emissions were actually discovered beginning in the late 1950's and 1960's whcih were centered around stars and planetary nebula (and could possibly have been from planetary sources).
see here: http://laserstars.org/history/hydroxyl.html
Interesting article...and a good list of refernces are included.
i'm not sure what sort of follow up has been done since; although there were some methanol and ammonium maser sources discovered around stars also...(see references).
Isolating them to planets rather than stellar emissions may be a problem.
I think rechecking for maser emssions in known extrasolars already recognized by other means is a good idea.
JW
G'day rom the land of ozzzzz
On a similar topic
Detection of Extrasolar Planets by Gravitational Microlensing
Feb-09
http://adsabs.harvard.edu/abs/2009arXiv0902.1761B
http://adsabs.harvard.edu/cgi-bin/nph-data...RINT&db_key=PRE
On a similar topic
Detection of Extrasolar Planets by Gravitational Microlensing
Feb-09
http://adsabs.harvard.edu/abs/2009arXiv0902.1761B
http://adsabs.harvard.edu/cgi-bin/nph-data...RINT&db_key=PRE
QUOTE
Gravitational microlensing provides a unique window on the properties and prevalence of extrasolar planetary systems because of its ability to find low-mass planets at separations of a few AU. The early evidence from microlensing indicates that the most common type of exoplanet yet detected are the so-called "super-Earth" planets of ~10 Earth-masses at a separation of a few AU from their host stars. The detection of two such planets indicates that roughly one third of stars have such planets in the separation range 1.5-4 AU, which is about an order of magnitude larger than the prevalence of gas-giant planets at these separations. We review the basic physics of the microlensing method, and show why this method allows the detection of Earth-mass planets at separations of 2-3 AU with ground-based observations. We explore the conditions that allow the detection of the planetary host stars and allow measurement of planetary orbital parameters. Finally, we show that a low-cost, space-based microlensing survey can provide a comprehensive statistical census of extrasolar planetary systems with sensitivity down to 0.1 Earth-masses at separations ranging from 0.5 AU to infinity.
QUOTE (Just Wonderful+May 11 2009, 09:19 AM)
However, just to inform you...stellar sources of OH microwave MASER emissions were actually discovered beginning in the late 1950's and 1960's whcih were centered around stars and planetary nebula (and could possibly have been from planetary sources).
It is true, many maser sources have been discovered since the Fifties. These sources, generated by molecular clouds extending on light-years or planetary nebulas extending on several hundreds million kilometers, are very wide.
A maser emitted by a planetary atmosphere will not be able to have, even in the case of a giant planet, a size higher than a few hundreds thousands kilometers. On stellar scale, they are quasi-punctual sources. The detection of these sources requires a great resolving power. In the radio field, that implies the use of interferometry.
QUOTE (daumic+May 18 2009, 10:19 PM)
A maser emitted by a planetary atmosphere will not be able to have, even in the case of a giant planet, a size higher than a few hundreds thousands kilometers. On stellar scale, they are quasi-punctual sources. The detection of these sources requires a great resolving power. In the radio field, that implies the use of interferometry.
In 2003 The Aussie Array discovered two exoplanetary water maser sources....resolution was down to 10 arcsec., , and the required sensitivity was achieveable.
The limiting factors are due to the fact that ...
Since the maser beam is highly collumnated and the planet rotates rapidly the sensitivity for detection is usually limited to a narrow band of time length .
Nevertheless, two positive maser detections were observed in the 22 Ghz range and more were being analysed as of this 2006 report: See page 807.
http://www.mso.anu.edu.au/~charley/papers/...eweaver2006.pdf
JW
You may want to get a later report from ATCA.
QUOTE (Just Wonderful+May 19 2009, 06:59 PM)
Nevertheless, two positive maser detections were observed in the 22 Ghz range and more were being analysed as of this 2006 report: See page 807.
http://www.mso.anu.edu.au/~charley/papers/...eweaver2006.pdf
JW
My mistake here....there were NO positive detections....in this report....
I am thinking of a 2003 report I have seen elsewhere.....lets see if I can find it.
QUOTE (Just Wonderful+May 19 2009, 06:59 PM)
Nevertheless, two positive maser detections were observed in the 22 Ghz range and more were being analysed as of this 2006 report: See page 807.
http://www.mso.anu.edu.au/~charley/papers/...eweaver2006.pdf
JW
You may want to get a later report from ATCA.
OK, my mistake ; it was Cosmovici (what a name) who picked up water maser signatures in 3 extrasolars in 2002 , , it was never confirmed.....but this type of detection can be elusive and difficult to confirm by its very nature.
JW
QUOTE (Just Wonderful+May 19 2009, 06:59 PM)
In 2003 The Aussie Array discovered two exoplanetary water maser sources....resolution was down to 10 arcsec., , and the required sensitivity was achieveable.
The limiting factors are due to the fact that ...
Since the maser beam is highly collumnated and the planet rotates rapidly the sensitivity for detection is usually limited to a narrow band of time length .
Nevertheless, two positive maser detections were observed in the 22 Ghz range and more were being analysed as of this 2006 report: See page 807.
http://www.mso.anu.edu.au/~charley/papers/...eweaver2006.pdf
JW
You may want to get a later report from ATCA.
Thank you for this message. I did not know this publication.
The angular resolution of the detector is of the order of 10 arcsec. By comparison, the angular diameter of a planet, even giant, from the distance of a few light-years is smaller than 0.001 arcsec.
As the authors shows it in the article, the angular resolution of the detector is sufficient to see very energetic phenomenon such as the impact of a comet. But it remains insufficient to distinguish from the background noise a less powerful source such as a continuous maser emission with a very small angular diameter.
The limiting factors are due to the fact that ...
Since the maser beam is highly collumnated and the planet rotates rapidly the sensitivity for detection is usually limited to a narrow band of time length .
Nevertheless, two positive maser detections were observed in the 22 Ghz range and more were being analysed as of this 2006 report: See page 807.
http://www.mso.anu.edu.au/~charley/papers/...eweaver2006.pdf
JW
You may want to get a later report from ATCA.
Thank you for this message. I did not know this publication.
The angular resolution of the detector is of the order of 10 arcsec. By comparison, the angular diameter of a planet, even giant, from the distance of a few light-years is smaller than 0.001 arcsec.
As the authors shows it in the article, the angular resolution of the detector is sufficient to see very energetic phenomenon such as the impact of a comet. But it remains insufficient to distinguish from the background noise a less powerful source such as a continuous maser emission with a very small angular diameter.
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