Determination of Habitable Zones in Extrasolar Planetary Systems: Where are Gaia's Sisters? <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <link rel="stylesheet" href="pik_neu.css" type="text/css"> </head> <body bgcolor="#FFFFFF" text="#000000" leftmargin="0" topmargin="0" marginwidth="0" marginheight="0" > <table width="101%" border="0" cellspacing="0" cellpadding="0" align="left" name="layout" > <tr> <td rowspan="3" align="left" valign="top"> <img src="images/spacer.gif" width="1" height="1"></td> <td align="left" valign="top" height="108"> <table width="521" border="0" cellpadding="0" cellspacing="0" name="header" height="108"> <tr> <td align="left" valign="top"><img src="images/spacer.gif" width="20" height="5"></td> <td align="left" valign="top"><img src="images/spacer.gif" width="85" height="5"></td> <td align="left" valign="top"><img src="images/spacer.gif" width="20" height="5"></td> <td align="left" valign="top"><img src="images/spacer.gif" width="313" height="5"></td> <td align="left" valign="top"> </td> </tr> <tr> <td align="left" valign="top"></td> <td align="left" valign="top" colspan="4"></td> </tr> <tr> <td align="left" valign="top"><img src="images/spacer.gif" width="20" height="10"></td> <td align="left" valign="bottom"> </td> <td align="left" valign="bottom"> </td> <td align="left" valign="bottom" class="singleline"> </td> <td align="left" valign="top" rowspan="3"><a href="http://www.pik-potsdam.de"><img src="images/logo.gif" width="82" height="82" border="0"></a></td> </tr> <tr> <td align="left" valign="top"><img src="images/spacer.gif" width="20" height="24"></td> <td align="left" valign="top" colspan="3"> </td> </tr> <tr> <td align="left" valign="top"><img src="images/spacer.gif" width="20" height="64"></td> <td colspan="3" align="left" valign="top"><a href="http://www.pik-potsdam.de/"><img src="images/titel.gif" width="418" height="40" border="0"></a></td> </tr> </table> </td> </tr> <tr> <td align="left" valign="top"> <table width="92%" border="0" cellpadding="0" cellspacing="0" name="content" > <tr valign="top"> <td align="left"><img src="images/spacer.gif" width="20" height="1"></td> <td align="left"><img src="images/spacer.gif" width="235" height="5"></td> <td align="left" width="100%"><img src="images/spacer.gif" width="135" height="5"></td> <td align="left"><img src="images/spacer.gif" width="40" height="20"></td> <td align="left"><img src="images/spacer.gif" width="180" height="1"></td> <td align="left"> </td> </tr> <tr> <td align="left" valign="top"> </td> <td align="left" valign="bottom" colspan="2"><span class="header_page">Werner von Bloh </span><br> <img src="images/orange.gif" width="100%" height="1"></td> <td align="left" valign="bottom"><img src="images/orange.gif" width="40" height="1"></td> <td align="left" valign="bottom"><img src="images/orange.gif" width="180" height="1"></td> </tr> <tr> <td align="left" valign="top"><img src="images/spacer.gif" width="20" height="44"></td> <td align="left" valign="bottom" colspan="2" height="3"> <span class="header"> Determination of Habitable Zones in Extrasolar Planetary Systems: Where are Gaia's Sisters? </span> </td> <td align="left" valign="top" rowspan="2"> </td> <td align="left" valign="top" rowspan="2" class="body"> <p><br><a href="../homepage/welcome.html">Werner von Bloh</a><img src="images/home2.gif" width="15" height="13"><br> <img src="images/purple.gif" width="180" height="1" vspace="3"><br> <a href="../homepage/welcome.html#projects">Projects involved</a><br> <img src="images/purple.gif" width="180" height="1" vspace="3"><br> <a href="../homepage/teaching">Teaching</a><br> <img src="images/purple.gif" width="180" height="1" vspace="3"><br> <a href="welcome.html">Publications</a><br> <img src="images/purple.gif" width="180" height="1" vspace="3"><br> <a href="../homepage/cv.html">Curriculum Vitae</a><br> <img src="images/purple.gif" width="180" height="1" vspace="3"><br> <a href="../parallel.html">Parallel programming</a><br> <img src="images/purple.gif" width="180" height="1" vspace="3"><br> <a href="../intranet">My intranet pages</a><br> <img src="images/purple.gif" width="180" height="1" vspace="3"><br> <a href="../mpeg">Animations</a><br> <img src="images/purple.gif" width="180" height="1" vspace="3"><br> <a href="../extern.html">External links</a><br> <img src="images/purple.gif" width="180" height="1" vspace="3"><br> </p></td> </tr> <tr align="left" valign="top"> <td> </td> <td colspan="2"><p><br>  <p class=body>S. Franck<sup>a</sup>, <A HREF="../homepage">W. von Bloh</A><sup>a</sup>, C. Bounama<sup>a</sup>, <A HREF="http://www.aip.de/~mst">M. Steffen</A><sup>b</sup>, D. Schönberner<sup>b</sup>, and <A HREF="/john">H.-J. Schellnhuber</A><sup>a</sup><br><br> <I>J. Geophys. Res. 105, no. E1, 1651-1658 (2000)</I> <P class=body> <sup>a</sup><A HREF="http://www.pik-potsdam.de">Potsdam Institute for Climate Impact Research</A> (PIK), Telegrafenberg, P.O. Box 60 12 03, 14412 Potsdam, Germany.</p> <P class=body> <sup>b</sup><A HREF="http://www.aip.de">Astrophysikalisches Institut Potsdam</A> (AIP), An der Sternwarte 16, D-14482 Potsdam, Germany. <p> <span class="header"><A NAME="part1">Abstract</A><br> <img src="images/purple.gif" width="100%" height="1"></span></p> <P class=body> A general modeling scheme for assessing the suitability for life of extrasolar planets is presented. The scheme focuses on the identification of the "habitable zone" in main-sequence star planetary systems accommodating Earth-like components. Our definition of habitability is based on the long-term possibility of photosynthetic biomass production under geodynamic conditions. Therefore, all the pertinent astrophysical, climatological, biogeochemical, and geodynamic processes involved in the generation of photosynthesis-driven life conditions are taken into account. Implicitly, a co-genetic origin of the central star and the orbiting planet is assumed. A geostatic model version is developed and investigated in parallel for demonstration purposes. The numerical solution of the advanced geodynamic model yields realistic look-up diagrams for convenient habitability determination. As an illustration, the MACHO-98-BLG-35 event is scrutinized. It is shown that this event is definitely not tantamount to the discovery of one of Gaia's sisters.</P> <P class=body>Full text of article incl. figures in <A HREF="../franck/jgr.pdf">PDF-format (380 KByte)</A>.</P> <P align=center> <IMG SRC="franck99c.gif" width="423" height="303" alt="Figure"> </P> <P class=figure> Figure: Shape of the GDM-HZ (green shading) in the mass-time plane for an Earth-like planet at distance <I>R</I> = 2 AU from the central star. The potential overall domain for accommodating the HZ for planets at some arbitrary distance is limited by a number of factors that are independent of <I>R</I>: (I) Minimum time for biosphere development (<I>t</I><sub>H</sub><0.8 Gyr excluded); (II) Central-star life time on the main sequence (<I>t</I>><I>t</I><sub>H</sub> excluded); (III) Geodynamics of the Earth-like planet (<I>t</I>><I>t</I><sub>max</sub> excluded); (IV) Tidal locking of the planet (non-trivial sub-domain excluded). The excluded realms are marked by grey shading in case of the first three factors, and by grey hatching for the tidal-locking effect. The horizontal red line represents the probable "life time" of the hypothetical MACHO-98-BLG-35 planet, which is assumed to orbit a 0.3 <I>M</I><sub>S</sub> star.</P> </td> </tr> <tr align="left" valign="top"> <td> </td> <td class="body" colspan="2"> <p><br> </p></td> <td class="body"> </td> <td class="body"> </td> </tr> <tr align="left" valign="top"> <td> </td> <td class="body" colspan="2"> </td> <td class="body"> </td> <td class="body"> </td> </tr> </table> </td> </tr> <tr> <td align="left" valign="bottom"> <table width="500" border="0" cellspacing="0" cellpadding="0"> <tr align="left" valign="top"> <td><img src="images/spacer.gif" width="20" height="1"></td> <td><img src="images/spacer.gif" width="140" height="1"></td> <td> </td> <td><img src="images/spacer.gif" width="400" height="1"></td> </tr> <tr> <td> </td> <td class="body"><a href="http://www.pik-potsdam.de/impressum">Impressum © PIK 2006</a></td> <td> </td> <td class="body"> </td> </tr> </table> </td> </tr> </table> </body> </html>