Knowledge

Emden–Chandrasekhar equation

Source 📝

17: 989: 983: 1125: 1721:
are constants which will be obtained with numerical solution. This behavior of density gives rise to increase in mass with increase in radius. Thus, the model is usually valid to describe the core of the star, where the temperature is approximately constant.
1469:
Assuming isothermal sphere has some disadvantages. Though the density obtained as solution of this isothermal gas sphere decreases from the centre, it decreases too slowly to give a well-defined surface and finite mass for the sphere. It can be shown that, as
793: 1263: 162: 2149: 1459: 2419: 361: 1955: 1341: 1676: 498: 2510: 2230: 1842: 848: 1002: 2307: 251: 684: 2762:
Chandrasekhar, S. (1972). A limiting case of relativistic equilibrium. In General Relativity (in honor of J. L. Synge), ed. L. O'Raifeartaigh. Oxford. Clarendon Press (pp. 185-199).
1163: 62: 2595: 2002: 2658: 2030: 2548: 1378: 1494: 1370: 1155: 278: 1762: 1719: 647: 2684: 553: 524: 205: 185: 2327: 2615: 2022: 1699: 836: 816: 672: 625: 603: 578: 404: 2733: 294: 1857: 1274: 1502: 2801: 370:
for a spherical vessel. The relativistic version of this spherically symmetric isothermal model was studied by Subrahmanyan Chandrasekhar in 1972.
2723:
Chandrasekhar, Subrahmanyan, and Subrahmanyan Chandrasekhar. An introduction to the study of stellar structure. Vol. 2. Courier Corporation, 1958.
2705: 419: 2430: 2160: 288:. The isothermal assumption is usually modeled to describe the core of a star. The equation is solved with the initial conditions, 2744:
Emden, R. (1907). Gaskugeln: Anwendungen der mechanischen Wärmetheorie auf kosmologische und meteorologische Probleme. B. Teubner.
1770: 2753:
Kippenhahn, Rudolf, Alfred Weigert, and Achim Weiss. Stellar structure and evolution. Vol. 282. Berlin: Springer-Verlag, 1990.
978:{\displaystyle {\frac {k_{B}T}{WH}}{\frac {1}{r^{2}}}{\frac {d}{dr}}\left(r^{2}{\frac {d\ln \rho }{dr}}\right)=-4\pi G\rho } 650: 2786: 2771:
Henrich, L. R., & Chandrasekhar, S. (1941). Stellar Models with Isothermal Cores. The Astrophysical Journal, 94, 525.
2734:
http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1949ApJ...109..551C&defaultprint=YES&filetype=.pdf
1120:{\displaystyle \psi =\ln {\frac {\rho _{c}}{\rho }},\quad \xi =r\left({\frac {4\pi G\rho _{c}WH}{k_{B}T}}\right)^{1/2}} 2241: 49: 2796: 2732:
Chandrasekhar, S., and Gordon W. Wares. "The Isothermal Function." The Astrophysical Journal 109 (1949): 551-554.
788:{\displaystyle {\frac {1}{r^{2}}}{\frac {d}{dr}}\left({\frac {r^{2}}{\rho }}{\frac {dp}{dr}}\right)=-4\pi G\rho } 2700: 678:
The equation for equilibrium of the star requires a balance between the pressure force and gravitational force
367: 210: 2695: 1258:{\displaystyle {\frac {1}{\xi ^{2}}}{\frac {d}{d\xi }}\left(\xi ^{2}{\frac {d\psi }{d\xi }}\right)=e^{-\psi }} 285: 157:{\displaystyle {\frac {1}{\xi ^{2}}}{\frac {d}{d\xi }}\left(\xi ^{2}{\frac {d\psi }{d\xi }}\right)=e^{-\psi }} 2791: 839: 2553: 366:
The equation appears in other branches of physics as well, for example the same equation appears in the
407: 2144:{\displaystyle {\frac {d^{2}z}{dt^{2}}}-{\frac {dz}{dt}}+e^{z}-2=0,\quad {\text{where}}\quad t=\ln x} 1963: 2623: 1454:{\displaystyle \psi ={\frac {\xi ^{2}}{6}}-{\frac {\xi ^{4}}{120}}+{\frac {\xi ^{6}}{1890}}+\cdots } 2318: 2620:
The solutions of the Emden–Chandrasekhar equation which are finite at the origin have necessarily
2524: 556: 411: 1473: 1349: 1133: 256: 1848: 1733: 1704: 632: 2663: 2414:{\displaystyle u={\frac {\xi e^{-\psi }}{d\psi /d\xi }},\quad v=\xi {\frac {d\psi }{d\xi }}} 581: 37: 531: 509: 280:
is the density of the gas at the centre. The equation has no known explicit solution. If a
190: 170: 2600: 2007: 1684: 821: 801: 657: 610: 588: 563: 389: 16: 2780: 356:{\displaystyle \psi =0,\quad {\frac {d\psi }{d\xi }}=0\quad {\text{at}}\quad \xi =0.} 33: 1950:{\displaystyle e^{-\psi _{s}}=2x^{2},\quad {\text{or}}\quad -\psi _{s}=2\ln x+\ln 2} 1336:{\displaystyle \psi =0,\quad {\frac {d\psi }{d\xi }}=0\quad {\text{at}}\quad \xi =0} 53: 45: 25: 1671:{\displaystyle {\frac {\rho }{\rho _{c}}}=e^{-\psi }={\frac {2}{\xi ^{2}}}\left} 379: 281: 41: 493:{\displaystyle p=\rho {\frac {k_{B}}{WH}}T+{\frac {4\sigma }{3c}}T^{4}} 2505:{\displaystyle {\frac {u}{v}}{\frac {dv}{du}}=-{\frac {u-1}{u+v-3}}} 988: 44:
gas sphere subjected to its own gravitational force, named after
2225:{\displaystyle y={\frac {dz}{dt}}=\xi {\frac {d\psi }{d\xi }}-2} 383: 284:
fluid is used instead of an isothermal fluid, one obtains the
1837:{\displaystyle x^{4}{\frac {d^{2}\psi }{dx^{2}}}=e^{-\psi }} 2154:
This equation can be reduced to first order by introducing
40:
for the density distribution of a spherically symmetric
2666: 2626: 2603: 2556: 2527: 2433: 2330: 2244: 2163: 2033: 2010: 1966: 1860: 1773: 1736: 1707: 1687: 1505: 1476: 1381: 1352: 1277: 1166: 1136: 1005: 851: 824: 804: 687: 660: 635: 613: 591: 566: 534: 512: 422: 392: 297: 259: 213: 193: 173: 65: 2550:
is a solution to Emden–Chandrasekhar equation, then
207:is the related to the density of the gas sphere as 2678: 2652: 2609: 2589: 2542: 2504: 2413: 2301: 2224: 2143: 2016: 1996: 1949: 1836: 1756: 1713: 1693: 1670: 1488: 1453: 1364: 1335: 1257: 1149: 1119: 977: 830: 810: 787: 666: 641: 619: 597: 572: 547: 518: 492: 398: 355: 272: 245: 199: 179: 156: 20:Numerical solution of Emden–Chandrasekhar equation 1960:Therefore, a new variable can be introduced as 2302:{\displaystyle y{\frac {dy}{dz}}-y+e^{z}-2=0} 1157:is the central density of the star, leads to 8: 818:is the radius measured from the center and 2597:is also a solution of the equation, where 2665: 2633: 2625: 2602: 2555: 2526: 2470: 2444: 2434: 2432: 2391: 2364: 2347: 2337: 2329: 2281: 2248: 2243: 2196: 2170: 2162: 2120: 2098: 2071: 2059: 2041: 2034: 2032: 2009: 1965: 1914: 1901: 1891: 1873: 1865: 1859: 1825: 1809: 1791: 1784: 1778: 1772: 1746: 1735: 1706: 1686: 1651: 1606: 1583: 1579: 1570: 1551: 1542: 1530: 1515: 1506: 1504: 1475: 1434: 1428: 1414: 1408: 1394: 1388: 1380: 1351: 1318: 1291: 1276: 1246: 1214: 1208: 1184: 1176: 1167: 1165: 1141: 1135: 1107: 1103: 1087: 1069: 1053: 1024: 1018: 1004: 926: 920: 896: 888: 879: 859: 852: 850: 823: 803: 742: 731: 725: 705: 697: 688: 686: 659: 634: 612: 590: 565: 539: 533: 511: 484: 460: 438: 432: 421: 391: 338: 311: 296: 264: 258: 246:{\displaystyle \rho =\rho _{c}e^{-\psi }} 234: 224: 212: 192: 172: 145: 113: 107: 83: 75: 66: 64: 987: 15: 2716: 992:Actual solution and asymptotic solution 52:. The equation was first introduced by 7: 2706:Chandrasekhar's white dwarf equation 2590:{\displaystyle \psi (A\xi )-2\ln A} 2317:There is another reduction due to 368:Frank-Kamenetskii explosion theory 14: 842:. The equation is re-written as 187:is the dimensionless radius and 2802:Ordinary differential equations 2381: 2125: 2119: 1997:{\displaystyle -\psi =2\ln x+z} 1906: 1900: 1730:Introducing the transformation 1323: 1317: 1290: 1038: 996:Introducing the transformation 343: 337: 310: 2653:{\displaystyle d\psi /d\xi =0} 2569: 2560: 2537: 2531: 1660: 1644: 627:is the temperature of the star 1: 1268:The boundary conditions are 30:Emden–Chandrasekhar equation 2543:{\displaystyle \psi (\xi )} 1764:transforms the equation to 56:in 1907. The equation reads 2818: 50:Subrahmanyan Chandrasekhar 2617:is an arbitrary constant. 2004:, where the equation for 1489:{\displaystyle \xi \gg 1} 1372:, the solution goes like 1365:{\displaystyle \xi \ll 1} 1150:{\displaystyle \rho _{c}} 651:Stefan–Boltzmann constant 605:is the mass of the proton 273:{\displaystyle \rho _{c}} 2701:Frank-Kamenetskii theory 1757:{\displaystyle x=1/\xi } 1465:Limitations of the model 1714:{\displaystyle \delta } 642:{\displaystyle \sigma } 2680: 2679:{\displaystyle \xi =0} 2654: 2611: 2591: 2544: 2506: 2415: 2303: 2226: 2145: 2018: 1998: 1951: 1838: 1758: 1715: 1695: 1672: 1490: 1455: 1366: 1337: 1259: 1151: 1121: 993: 979: 840:gravitational constant 832: 812: 789: 668: 643: 621: 599: 574: 549: 520: 494: 400: 357: 274: 247: 201: 181: 158: 21: 2681: 2655: 2612: 2592: 2545: 2507: 2416: 2304: 2227: 2146: 2019: 1999: 1952: 1839: 1759: 1716: 1696: 1673: 1491: 1456: 1367: 1338: 1260: 1152: 1122: 991: 980: 833: 813: 790: 674:is the speed of light 669: 644: 622: 600: 575: 550: 548:{\displaystyle k_{B}} 521: 519:{\displaystyle \rho } 495: 401: 358: 275: 248: 202: 200:{\displaystyle \psi } 182: 159: 19: 2787:Equations of physics 2664: 2624: 2601: 2554: 2525: 2431: 2328: 2242: 2161: 2031: 2008: 1964: 1858: 1771: 1734: 1705: 1685: 1503: 1474: 1379: 1350: 1275: 1164: 1134: 1003: 849: 822: 802: 685: 658: 633: 611: 589: 564: 532: 510: 420: 390: 295: 257: 211: 191: 180:{\displaystyle \xi } 171: 63: 2696:Lane–Emden equation 2319:Edward Arthur Milne 1847:The equation has a 286:Lane–Emden equation 2676: 2650: 2607: 2587: 2540: 2502: 2411: 2299: 2222: 2141: 2014: 1994: 1947: 1834: 1754: 1711: 1691: 1668: 1486: 1451: 1362: 1333: 1255: 1147: 1117: 994: 975: 828: 808: 785: 664: 639: 617: 595: 570: 557:Boltzmann constant 545: 516: 490: 412:radiation pressure 396: 353: 270: 243: 197: 177: 154: 22: 2610:{\displaystyle A} 2500: 2462: 2442: 2409: 2376: 2266: 2214: 2188: 2123: 2089: 2066: 2017:{\displaystyle z} 1904: 1849:singular solution 1816: 1726:Singular solution 1694:{\displaystyle A} 1616: 1612: 1593: 1557: 1521: 1443: 1423: 1403: 1321: 1309: 1232: 1197: 1182: 1097: 1033: 950: 909: 894: 877: 831:{\displaystyle G} 811:{\displaystyle r} 760: 740: 718: 703: 667:{\displaystyle c} 620:{\displaystyle T} 598:{\displaystyle H} 573:{\displaystyle W} 478: 452: 399:{\displaystyle p} 341: 329: 131: 96: 81: 2809: 2797:Stellar dynamics 2772: 2769: 2763: 2760: 2754: 2751: 2745: 2742: 2736: 2730: 2724: 2721: 2685: 2683: 2682: 2677: 2659: 2657: 2656: 2651: 2637: 2616: 2614: 2613: 2608: 2596: 2594: 2593: 2588: 2549: 2547: 2546: 2541: 2511: 2509: 2508: 2503: 2501: 2499: 2482: 2471: 2463: 2461: 2453: 2445: 2443: 2435: 2420: 2418: 2417: 2412: 2410: 2408: 2400: 2392: 2377: 2375: 2368: 2356: 2355: 2354: 2338: 2321:. Let us define 2308: 2306: 2305: 2300: 2286: 2285: 2267: 2265: 2257: 2249: 2231: 2229: 2228: 2223: 2215: 2213: 2205: 2197: 2189: 2187: 2179: 2171: 2150: 2148: 2147: 2142: 2124: 2121: 2103: 2102: 2090: 2088: 2080: 2072: 2067: 2065: 2064: 2063: 2050: 2046: 2045: 2035: 2024:can be derived, 2023: 2021: 2020: 2015: 2003: 2001: 2000: 1995: 1956: 1954: 1953: 1948: 1919: 1918: 1905: 1902: 1896: 1895: 1880: 1879: 1878: 1877: 1843: 1841: 1840: 1835: 1833: 1832: 1817: 1815: 1814: 1813: 1800: 1796: 1795: 1785: 1783: 1782: 1763: 1761: 1760: 1755: 1750: 1720: 1718: 1717: 1712: 1700: 1698: 1697: 1692: 1677: 1675: 1674: 1669: 1667: 1663: 1659: 1658: 1637: 1633: 1617: 1608: 1607: 1594: 1592: 1591: 1587: 1571: 1558: 1556: 1555: 1543: 1538: 1537: 1522: 1520: 1519: 1507: 1495: 1493: 1492: 1487: 1460: 1458: 1457: 1452: 1444: 1439: 1438: 1429: 1424: 1419: 1418: 1409: 1404: 1399: 1398: 1389: 1371: 1369: 1368: 1363: 1342: 1340: 1339: 1334: 1322: 1319: 1310: 1308: 1300: 1292: 1264: 1262: 1261: 1256: 1254: 1253: 1238: 1234: 1233: 1231: 1223: 1215: 1213: 1212: 1198: 1196: 1185: 1183: 1181: 1180: 1168: 1156: 1154: 1153: 1148: 1146: 1145: 1126: 1124: 1123: 1118: 1116: 1115: 1111: 1102: 1098: 1096: 1092: 1091: 1081: 1074: 1073: 1054: 1034: 1029: 1028: 1019: 984: 982: 981: 976: 956: 952: 951: 949: 941: 927: 925: 924: 910: 908: 897: 895: 893: 892: 880: 878: 876: 868: 864: 863: 853: 837: 835: 834: 829: 817: 815: 814: 809: 794: 792: 791: 786: 766: 762: 761: 759: 751: 743: 741: 736: 735: 726: 719: 717: 706: 704: 702: 701: 689: 673: 671: 670: 665: 648: 646: 645: 640: 626: 624: 623: 618: 604: 602: 601: 596: 582:molecular weight 579: 577: 576: 571: 554: 552: 551: 546: 544: 543: 525: 523: 522: 517: 499: 497: 496: 491: 489: 488: 479: 477: 469: 461: 453: 451: 443: 442: 433: 408:kinetic pressure 405: 403: 402: 397: 362: 360: 359: 354: 342: 339: 330: 328: 320: 312: 279: 277: 276: 271: 269: 268: 252: 250: 249: 244: 242: 241: 229: 228: 206: 204: 203: 198: 186: 184: 183: 178: 163: 161: 160: 155: 153: 152: 137: 133: 132: 130: 122: 114: 112: 111: 97: 95: 84: 82: 80: 79: 67: 38:Poisson equation 2817: 2816: 2812: 2811: 2810: 2808: 2807: 2806: 2777: 2776: 2775: 2770: 2766: 2761: 2757: 2752: 2748: 2743: 2739: 2731: 2727: 2722: 2718: 2714: 2692: 2662: 2661: 2622: 2621: 2599: 2598: 2552: 2551: 2523: 2522: 2518: 2483: 2472: 2454: 2446: 2429: 2428: 2401: 2393: 2357: 2343: 2339: 2326: 2325: 2315: 2277: 2258: 2250: 2240: 2239: 2206: 2198: 2180: 2172: 2159: 2158: 2094: 2081: 2073: 2055: 2051: 2037: 2036: 2029: 2028: 2006: 2005: 1962: 1961: 1910: 1887: 1869: 1861: 1856: 1855: 1821: 1805: 1801: 1787: 1786: 1774: 1769: 1768: 1732: 1731: 1728: 1703: 1702: 1683: 1682: 1647: 1605: 1601: 1575: 1563: 1559: 1547: 1526: 1511: 1501: 1500: 1472: 1471: 1467: 1430: 1410: 1390: 1377: 1376: 1348: 1347: 1301: 1293: 1273: 1272: 1242: 1224: 1216: 1204: 1203: 1199: 1189: 1172: 1162: 1161: 1137: 1132: 1131: 1083: 1082: 1065: 1055: 1049: 1048: 1020: 1001: 1000: 942: 928: 916: 915: 911: 901: 884: 869: 855: 854: 847: 846: 820: 819: 800: 799: 752: 744: 727: 724: 720: 710: 693: 683: 682: 656: 655: 631: 630: 609: 608: 587: 586: 562: 561: 535: 530: 529: 508: 507: 480: 470: 462: 444: 434: 418: 417: 388: 387: 386:, the pressure 376: 321: 313: 293: 292: 260: 255: 254: 230: 220: 209: 208: 189: 188: 169: 168: 165: 141: 123: 115: 103: 102: 98: 88: 71: 61: 60: 12: 11: 5: 2815: 2813: 2805: 2804: 2799: 2794: 2792:Fluid dynamics 2789: 2779: 2778: 2774: 2773: 2764: 2755: 2746: 2737: 2725: 2715: 2713: 2710: 2709: 2708: 2703: 2698: 2691: 2688: 2687: 2686: 2675: 2672: 2669: 2649: 2646: 2643: 2640: 2636: 2632: 2629: 2618: 2606: 2586: 2583: 2580: 2577: 2574: 2571: 2568: 2565: 2562: 2559: 2539: 2536: 2533: 2530: 2517: 2514: 2513: 2512: 2498: 2495: 2492: 2489: 2486: 2481: 2478: 2475: 2469: 2466: 2460: 2457: 2452: 2449: 2441: 2438: 2422: 2421: 2407: 2404: 2399: 2396: 2390: 2387: 2384: 2380: 2374: 2371: 2367: 2363: 2360: 2353: 2350: 2346: 2342: 2336: 2333: 2314: 2311: 2310: 2309: 2298: 2295: 2292: 2289: 2284: 2280: 2276: 2273: 2270: 2264: 2261: 2256: 2253: 2247: 2233: 2232: 2221: 2218: 2212: 2209: 2204: 2201: 2195: 2192: 2186: 2183: 2178: 2175: 2169: 2166: 2152: 2151: 2140: 2137: 2134: 2131: 2128: 2118: 2115: 2112: 2109: 2106: 2101: 2097: 2093: 2087: 2084: 2079: 2076: 2070: 2062: 2058: 2054: 2049: 2044: 2040: 2013: 1993: 1990: 1987: 1984: 1981: 1978: 1975: 1972: 1969: 1958: 1957: 1946: 1943: 1940: 1937: 1934: 1931: 1928: 1925: 1922: 1917: 1913: 1909: 1899: 1894: 1890: 1886: 1883: 1876: 1872: 1868: 1864: 1845: 1844: 1831: 1828: 1824: 1820: 1812: 1808: 1804: 1799: 1794: 1790: 1781: 1777: 1753: 1749: 1745: 1742: 1739: 1727: 1724: 1710: 1690: 1679: 1678: 1666: 1662: 1657: 1654: 1650: 1646: 1643: 1640: 1636: 1632: 1629: 1626: 1623: 1620: 1615: 1611: 1604: 1600: 1597: 1590: 1586: 1582: 1578: 1574: 1569: 1566: 1562: 1554: 1550: 1546: 1541: 1536: 1533: 1529: 1525: 1518: 1514: 1510: 1485: 1482: 1479: 1466: 1463: 1462: 1461: 1450: 1447: 1442: 1437: 1433: 1427: 1422: 1417: 1413: 1407: 1402: 1397: 1393: 1387: 1384: 1361: 1358: 1355: 1344: 1343: 1332: 1329: 1326: 1316: 1313: 1307: 1304: 1299: 1296: 1289: 1286: 1283: 1280: 1266: 1265: 1252: 1249: 1245: 1241: 1237: 1230: 1227: 1222: 1219: 1211: 1207: 1202: 1195: 1192: 1188: 1179: 1175: 1171: 1144: 1140: 1128: 1127: 1114: 1110: 1106: 1101: 1095: 1090: 1086: 1080: 1077: 1072: 1068: 1064: 1061: 1058: 1052: 1047: 1044: 1041: 1037: 1032: 1027: 1023: 1017: 1014: 1011: 1008: 986: 985: 974: 971: 968: 965: 962: 959: 955: 948: 945: 940: 937: 934: 931: 923: 919: 914: 907: 904: 900: 891: 887: 883: 875: 872: 867: 862: 858: 827: 807: 796: 795: 784: 781: 778: 775: 772: 769: 765: 758: 755: 750: 747: 739: 734: 730: 723: 716: 713: 709: 700: 696: 692: 676: 675: 663: 653: 638: 628: 616: 606: 594: 584: 569: 559: 542: 538: 527: 526:is the density 515: 501: 500: 487: 483: 476: 473: 468: 465: 459: 456: 450: 447: 441: 437: 431: 428: 425: 406:is due to the 395: 375: 372: 364: 363: 352: 349: 346: 336: 333: 327: 324: 319: 316: 309: 306: 303: 300: 267: 263: 240: 237: 233: 227: 223: 219: 216: 196: 176: 151: 148: 144: 140: 136: 129: 126: 121: 118: 110: 106: 101: 94: 91: 87: 78: 74: 70: 58: 13: 10: 9: 6: 4: 3: 2: 2814: 2803: 2800: 2798: 2795: 2793: 2790: 2788: 2785: 2784: 2782: 2768: 2765: 2759: 2756: 2750: 2747: 2741: 2738: 2735: 2729: 2726: 2720: 2717: 2711: 2707: 2704: 2702: 2699: 2697: 2694: 2693: 2689: 2673: 2670: 2667: 2647: 2644: 2641: 2638: 2634: 2630: 2627: 2619: 2604: 2584: 2581: 2578: 2575: 2572: 2566: 2563: 2557: 2534: 2528: 2520: 2519: 2515: 2496: 2493: 2490: 2487: 2484: 2479: 2476: 2473: 2467: 2464: 2458: 2455: 2450: 2447: 2439: 2436: 2427: 2426: 2425: 2405: 2402: 2397: 2394: 2388: 2385: 2382: 2378: 2372: 2369: 2365: 2361: 2358: 2351: 2348: 2344: 2340: 2334: 2331: 2324: 2323: 2322: 2320: 2312: 2296: 2293: 2290: 2287: 2282: 2278: 2274: 2271: 2268: 2262: 2259: 2254: 2251: 2245: 2238: 2237: 2236: 2235:then we have 2219: 2216: 2210: 2207: 2202: 2199: 2193: 2190: 2184: 2181: 2176: 2173: 2167: 2164: 2157: 2156: 2155: 2138: 2135: 2132: 2129: 2126: 2116: 2113: 2110: 2107: 2104: 2099: 2095: 2091: 2085: 2082: 2077: 2074: 2068: 2060: 2056: 2052: 2047: 2042: 2038: 2027: 2026: 2025: 2011: 1991: 1988: 1985: 1982: 1979: 1976: 1973: 1970: 1967: 1944: 1941: 1938: 1935: 1932: 1929: 1926: 1923: 1920: 1915: 1911: 1907: 1897: 1892: 1888: 1884: 1881: 1874: 1870: 1866: 1862: 1854: 1853: 1852: 1850: 1829: 1826: 1822: 1818: 1810: 1806: 1802: 1797: 1792: 1788: 1779: 1775: 1767: 1766: 1765: 1751: 1747: 1743: 1740: 1737: 1725: 1723: 1708: 1688: 1664: 1655: 1652: 1648: 1641: 1638: 1634: 1630: 1627: 1624: 1621: 1618: 1613: 1609: 1602: 1598: 1595: 1588: 1584: 1580: 1576: 1572: 1567: 1564: 1560: 1552: 1548: 1544: 1539: 1534: 1531: 1527: 1523: 1516: 1512: 1508: 1499: 1498: 1497: 1483: 1480: 1477: 1464: 1448: 1445: 1440: 1435: 1431: 1425: 1420: 1415: 1411: 1405: 1400: 1395: 1391: 1385: 1382: 1375: 1374: 1373: 1359: 1356: 1353: 1330: 1327: 1324: 1314: 1311: 1305: 1302: 1297: 1294: 1287: 1284: 1281: 1278: 1271: 1270: 1269: 1250: 1247: 1243: 1239: 1235: 1228: 1225: 1220: 1217: 1209: 1205: 1200: 1193: 1190: 1186: 1177: 1173: 1169: 1160: 1159: 1158: 1142: 1138: 1112: 1108: 1104: 1099: 1093: 1088: 1084: 1078: 1075: 1070: 1066: 1062: 1059: 1056: 1050: 1045: 1042: 1039: 1035: 1030: 1025: 1021: 1015: 1012: 1009: 1006: 999: 998: 997: 990: 972: 969: 966: 963: 960: 957: 953: 946: 943: 938: 935: 932: 929: 921: 917: 912: 905: 902: 898: 889: 885: 881: 873: 870: 865: 860: 856: 845: 844: 843: 841: 825: 805: 782: 779: 776: 773: 770: 767: 763: 756: 753: 748: 745: 737: 732: 728: 721: 714: 711: 707: 698: 694: 690: 681: 680: 679: 661: 654: 652: 636: 629: 614: 607: 592: 585: 583: 567: 560: 558: 540: 536: 528: 513: 506: 505: 504: 485: 481: 474: 471: 466: 463: 457: 454: 448: 445: 439: 435: 429: 426: 423: 416: 415: 414: 413: 409: 393: 385: 381: 373: 371: 369: 350: 347: 344: 334: 331: 325: 322: 317: 314: 307: 304: 301: 298: 291: 290: 289: 287: 283: 265: 261: 238: 235: 231: 225: 221: 217: 214: 194: 174: 164: 149: 146: 142: 138: 134: 127: 124: 119: 116: 108: 104: 99: 92: 89: 85: 76: 72: 68: 57: 55: 51: 47: 43: 39: 35: 34:dimensionless 31: 27: 18: 2767: 2758: 2749: 2740: 2728: 2719: 2423: 2316: 2234: 2153: 1959: 1846: 1729: 1680: 1468: 1345: 1267: 1129: 995: 797: 677: 580:is the mean 502: 377: 365: 166: 59: 54:Robert Emden 46:Robert Emden 36:form of the 29: 26:astrophysics 23: 2781:Categories 2712:References 2516:Properties 380:isothermal 374:Derivation 282:polytropic 42:isothermal 2668:ξ 2642:ξ 2631:ψ 2582:⁡ 2573:− 2567:ξ 2558:ψ 2535:ξ 2529:ψ 2494:− 2477:− 2468:− 2406:ξ 2398:ψ 2389:ξ 2373:ξ 2362:ψ 2352:ψ 2349:− 2341:ξ 2313:Reduction 2288:− 2269:− 2217:− 2211:ξ 2203:ψ 2194:ξ 2136:⁡ 2105:− 2069:− 1983:⁡ 1971:ψ 1968:− 1942:⁡ 1930:⁡ 1912:ψ 1908:− 1871:ψ 1867:− 1851:given by 1830:ψ 1827:− 1798:ψ 1752:ξ 1709:δ 1653:− 1649:ξ 1631:δ 1625:ξ 1622:⁡ 1599:⁡ 1577:ξ 1549:ξ 1535:ψ 1532:− 1513:ρ 1509:ρ 1481:≫ 1478:ξ 1449:⋯ 1432:ξ 1412:ξ 1406:− 1392:ξ 1383:ψ 1357:≪ 1354:ξ 1325:ξ 1306:ξ 1298:ψ 1279:ψ 1251:ψ 1248:− 1229:ξ 1221:ψ 1206:ξ 1194:ξ 1174:ξ 1139:ρ 1067:ρ 1060:π 1040:ξ 1031:ρ 1022:ρ 1016:⁡ 1007:ψ 973:ρ 967:π 961:− 939:ρ 936:⁡ 783:ρ 777:π 771:− 738:ρ 637:σ 514:ρ 467:σ 430:ρ 345:ξ 326:ξ 318:ψ 299:ψ 262:ρ 239:ψ 236:− 222:ρ 215:ρ 195:ψ 175:ξ 150:ψ 147:− 128:ξ 120:ψ 105:ξ 93:ξ 73:ξ 2690:See also 382:gaseous 253:, where 838:is the 649:is the 555:is the 378:For an 1681:where 1130:where 798:where 503:where 167:where 28:, the 2424:then 2122:where 32:is a 1701:and 1441:1890 1346:For 410:and 384:star 48:and 2660:at 2521:If 1596:cos 1421:120 24:In 2783:: 2579:ln 2133:ln 1980:ln 1939:ln 1927:ln 1903:or 1619:ln 1496:, 1320:at 1013:ln 933:ln 351:0. 340:at 2674:0 2671:= 2648:0 2645:= 2639:d 2635:/ 2628:d 2605:A 2585:A 2576:2 2570:) 2564:A 2561:( 2538:) 2532:( 2497:3 2491:v 2488:+ 2485:u 2480:1 2474:u 2465:= 2459:u 2456:d 2451:v 2448:d 2440:v 2437:u 2403:d 2395:d 2386:= 2383:v 2379:, 2370:d 2366:/ 2359:d 2345:e 2335:= 2332:u 2297:0 2294:= 2291:2 2283:z 2279:e 2275:+ 2272:y 2263:z 2260:d 2255:y 2252:d 2246:y 2220:2 2208:d 2200:d 2191:= 2185:t 2182:d 2177:z 2174:d 2168:= 2165:y 2139:x 2130:= 2127:t 2117:, 2114:0 2111:= 2108:2 2100:z 2096:e 2092:+ 2086:t 2083:d 2078:z 2075:d 2061:2 2057:t 2053:d 2048:z 2043:2 2039:d 2012:z 1992:z 1989:+ 1986:x 1977:2 1974:= 1945:2 1936:+ 1933:x 1924:2 1921:= 1916:s 1898:, 1893:2 1889:x 1885:2 1882:= 1875:s 1863:e 1823:e 1819:= 1811:2 1807:x 1803:d 1793:2 1789:d 1780:4 1776:x 1748:/ 1744:1 1741:= 1738:x 1689:A 1665:] 1661:) 1656:1 1645:( 1642:O 1639:+ 1635:) 1628:+ 1614:2 1610:7 1603:( 1589:2 1585:/ 1581:1 1573:A 1568:+ 1565:1 1561:[ 1553:2 1545:2 1540:= 1528:e 1524:= 1517:c 1484:1 1446:+ 1436:6 1426:+ 1416:4 1401:6 1396:2 1386:= 1360:1 1331:0 1328:= 1315:0 1312:= 1303:d 1295:d 1288:, 1285:0 1282:= 1244:e 1240:= 1236:) 1226:d 1218:d 1210:2 1201:( 1191:d 1187:d 1178:2 1170:1 1143:c 1113:2 1109:/ 1105:1 1100:) 1094:T 1089:B 1085:k 1079:H 1076:W 1071:c 1063:G 1057:4 1051:( 1046:r 1043:= 1036:, 1026:c 1010:= 970:G 964:4 958:= 954:) 947:r 944:d 930:d 922:2 918:r 913:( 906:r 903:d 899:d 890:2 886:r 882:1 874:H 871:W 866:T 861:B 857:k 826:G 806:r 780:G 774:4 768:= 764:) 757:r 754:d 749:p 746:d 733:2 729:r 722:( 715:r 712:d 708:d 699:2 695:r 691:1 662:c 615:T 593:H 568:W 541:B 537:k 486:4 482:T 475:c 472:3 464:4 458:+ 455:T 449:H 446:W 440:B 436:k 427:= 424:p 394:p 348:= 335:0 332:= 323:d 315:d 308:, 305:0 302:= 266:c 232:e 226:c 218:= 143:e 139:= 135:) 125:d 117:d 109:2 100:( 90:d 86:d 77:2 69:1

Index


astrophysics
dimensionless
Poisson equation
isothermal
Robert Emden
Subrahmanyan Chandrasekhar
Robert Emden
polytropic
Lane–Emden equation
Frank-Kamenetskii explosion theory
isothermal
star
kinetic pressure
radiation pressure
Boltzmann constant
molecular weight
Stefan–Boltzmann constant
gravitational constant

singular solution
Edward Arthur Milne
Lane–Emden equation
Frank-Kamenetskii theory
Chandrasekhar's white dwarf equation
http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1949ApJ...109..551C&defaultprint=YES&filetype=.pdf
Categories
Equations of physics
Fluid dynamics
Stellar dynamics

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.