"Seeing" extrasolar planets w/polarization

[docm]

http://www.physorg.com/news117897716.html<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p><b>Polarization technique focuses limelight<br /><br /><i>The ability to explore remote worlds in space has been enhanced through a polarization technique that allows the first ever detection of light reflected by extrasolar (exoplanet) planets. The study has been accepted for publication in Astrophysical Journal Letters.</i></b><br /><br />An international team of astronomers, led by Professor Svetlana Berdyugina of ETH Zurich’s Institute of Astronomy, has for the first time ever been able to detect and monitor the visible light that is scattered in the atmosphere of an exoplanet.<br /><br />Employing techniques similar to how Polaroid sunglasses filter away reflected sunlight to reduce glare, the team of scientists were able to extract polarized light to enhance the faint reflected starlight ‘glare’ from an exoplanet. As a result, the scientists could infer the size of its swollen atmosphere. They also directly traced the orbit of the planet, a feat of visualization not possible using indirect methods.<br /><br /><b>Hot Jupiter</b><br /><br />The transiting exoplanet under study circles the dwarf star HD189733 in the constellation Vulpecula and lies more than 60 light years from the earth. Known as HD189733b, this exoplanet was discovered two years ago via Doppler spec-troscopy. HD189733b is so close to its parent star that its atmosphere expands from the heat. Until now, astronomers have never seen light reflected from an exoplanet, although they have deduced from other observations that HD189733b probably resembles a ‘hot Jupiter’ – a planet orbiting extremely closely to its parent star. Unlike Jupiter, however, HD189733b orbits its star in a couple of days rather than the 12 years it takes Jupiter to make one orbit of the sun.<br /><br /><b>Two half-moon phases</b><br /><br />The interna</p></blockquote> <div class="Discussion_UserSignature"> </div>

 

[qso1]

I hope they will soon get around to looking at stars within 20 Ly of earth. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[cbased]

This was achieved from a ground based telescope! I can't wait to see the new generation of telescopes launched - how many new discoveries they will make!

 

[keermalec]

Awesome discovery, the full ()January 20, 2008!) article is here. <div class="Discussion_UserSignature"> <p><em>“An error does not become a mistake until you refuse to correct it.” John F. Kennedy</em></p> </div>

 

[3488]

This is awsome stuff. Thank you very much for posting this & thank you docm for<br />starting this.<br /><br />Regarding planets within 20 LY, I can see Alpha Centauri, Epsilon Eridani, Tau Ceti,<br />Sirius, Procyon, etc being studied for this.<br /><br />The article was early, was it not???<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[comga]

Thanks for the link.<br /><br />This is remarkable. The amount of information they have extracted from these measurements is impressive.<br /><br />The article states that the detection is largely photon limited. Yet they achieved this with a 60 cm telescope and 20 to 30 minutes of exposure per night. With a 6 meter telescope there would be 1E4 times as much energy. A Keck telescope has nearly 3E4 times the area and I can envision methods that would make use of all this increased power. <br /><br />It is clear this demonstrates a very powerful technique. The authors are to be commended. <br />