{"id":273,"date":"2018-11-19T09:39:17","date_gmt":"2018-11-19T09:39:17","guid":{"rendered":"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/?post_type=chapter&#038;p=273"},"modified":"2018-11-19T09:39:17","modified_gmt":"2018-11-19T09:39:17","slug":"the-sun-basic-data-contd","status":"publish","type":"chapter","link":"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/chapter\/the-sun-basic-data-contd\/","title":{"rendered":"The Sun \u2013 Basic Data (Contd.)"},"content":{"raw":"&nbsp;\r\n\r\n<strong>1.\u00a0 Learning Outcomes<\/strong>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\">After studying this module, you should be able to<\/p>\r\n\r\n<ul>\r\n \t<li style=\"text-align: justify\">enumerate the various methods used to measure the solar surface temperature<\/li>\r\n \t<li style=\"text-align: justify\">discuss the Wien\u2019s displacement law in physics and its use in measuring solar temperature<\/li>\r\n \t<li style=\"text-align: justify\">explain the application of Stefan-Boltzmann law to the solar surface temperature using the luminosity and the radius of the Sun<\/li>\r\n \t<li style=\"text-align: justify\">describe how the fitting of black body curve to the observed solar spectrum yields the solar surface temperature<\/li>\r\n \t<li style=\"text-align: justify\">derive the temperature of the Sun using its observed colour index<\/li>\r\n \t<li style=\"text-align: justify\">explain why the temperatures derived using various methods do not agree with one another<\/li>\r\n \t<li style=\"text-align: justify\">describe the layers of the solar atmosphere and explain why they are seen except when the solar disc is covered<\/li>\r\n<\/ul>\r\n&nbsp;\r\n\r\n<strong>2.\u00a0 Introduction<\/strong>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify\"><span style=\"text-align: initial;text-indent: 1em;font-size: 1em\">In the last module, Module 20, we discussed some basic parameters which characterize the Sun. The first parameter to be discussed was the distance of the Sun from the earth, a quantity called Astronomical Unit. This distance plays a key role in estimating the mass and luminosity of the Sun.\u00a0 We discussed the attempts made by ancient astronomers, using transits of planets in front of the solar disc to estimate the Sun\u2019s distance from the earth.\u00a0 We also discussed how they used a particular phase of the moon and moon\u2019s distance from the earth for this purpose. Then we discussed the modern method of finding this distance.<\/span><\/p>\r\n&nbsp;\r\n<p style=\"text-align: justify\">Using the distance of the Sun, we could estimate the mass of the Sun by equating the centripetal force acting on the earth and the gravitational force of the Sun which holds earth in its orbit.<\/p>\r\n&nbsp;\r\n<p style=\"text-align: justify\">Another parameter that could be found using the distance was the radius of the Sun. It is easy to find the angular diameter of the Sun and multiplying it with the distance of the Sun, the size of the Sun could be accurately calculated.<\/p>\r\n&nbsp;\r\n<p style=\"text-align: justify\">Yet another important parameter, luminosity of the Sun, was also discussed.\u00a0 The energy falling per second on a square meter of a surface placed outside the earth\u2019s atmosphere normal to the rays of the Sun is called the solar constant. So, if we draw a sphere of radius equal to one AU centred on the earth, each square meter of its surface receives energy equal to the solar constant. Multiplying the total surface area of this sphere by the solar constant enables us to calculate the total energy emitted by the sun every second. That is the luminosity of the Sun. \u00a0Just to digress a bit, variations in the solar constant were also discussed since they may be important in connection with the weather and climate change on the earth and global warming we are witnessing today.<\/p>\r\n&nbsp;\r\n<p style=\"text-align: justify\">An important data for the Sun is its surface temperature, or effective temperature, which we now discuss.<\/p>\r\n&nbsp;\r\n\r\n<img class=\"aligncenter wp-image-286 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_03-e1542619345257.jpg\" alt=\"\" width=\"1996\" height=\"2532\" \/> <img class=\"aligncenter wp-image-285 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_04-e1542619373381.jpg\" alt=\"\" width=\"1963\" height=\"2590\" \/> <img class=\"aligncenter wp-image-284 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_05-e1542619403612.jpg\" alt=\"\" width=\"1971\" height=\"2730\" \/> <img class=\"aligncenter wp-image-283 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_06-e1542619467545.jpg\" alt=\"\" width=\"1938\" height=\"2689\" \/> <img class=\"aligncenter wp-image-282 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_07-e1542619564662.jpg\" alt=\"\" width=\"2004\" height=\"2301\" \/> <img class=\"aligncenter wp-image-281 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_08-e1542619591596.jpg\" alt=\"\" width=\"1988\" height=\"2186\" \/> <img class=\"aligncenter wp-image-280 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_09-e1542619618589.jpg\" alt=\"\" width=\"2029\" height=\"2730\" \/> <img class=\"aligncenter wp-image-279 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_10-e1542619648922.jpg\" alt=\"\" width=\"2021\" height=\"2211\" \/> <img class=\"aligncenter wp-image-278 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_11-e1542619698672.jpg\" alt=\"\" width=\"2021\" height=\"2673\" \/> <img class=\"aligncenter wp-image-277 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_12-e1542619721722.jpg\" alt=\"\" width=\"2004\" height=\"2739\" \/> <img class=\"aligncenter wp-image-276 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_13-e1542619749402.jpg\" alt=\"\" width=\"2004\" height=\"734\" \/> <img class=\"aligncenter wp-image-275 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_14-e1542619783590.jpg\" alt=\"\" width=\"1980\" height=\"2697\" \/> <img class=\"aligncenter wp-image-274 \" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_15-e1542619801669.jpg\" alt=\"\" width=\"777\" height=\"184\" \/>\r\n\r\n&nbsp;\r\n\r\n<strong><span style=\"font-size: 1em\">Suggested Readings<\/span><\/strong>\r\n<ul>\r\n \t<li><span style=\"font-size: 1em\">http:\/\/www.eurastro.de\/webpages\/MRSPECT.HTM<\/span><\/li>\r\n \t<li><span style=\"font-size: 1em\">http:\/\/kho.unis.no\/Eclipse\/index_Cor.html<\/span><\/li>\r\n \t<li><span style=\"font-size: 1em\">http:\/\/cseligman.com\/text\/sun\/sunatmosphere.htm<\/span><\/li>\r\n \t<li><span style=\"font-size: 1em\">http:\/\/iopscience.iop.org\/article\/10.1086\/301490\/fulltext\/<\/span><\/li>\r\n \t<li><span style=\"font-size: 1em\">http:\/\/www.vendian.org\/mncharity\/dir3\/starcolor\/details.html<\/span><\/li>\r\n<\/ul>\r\n&nbsp;\r\n\r\n<span style=\"font-size: 1em\">Ballestero (Ballesteros, F.J. (2012). \"New insights into black bodies \". EPL (Europhysics Letters) 97 (2012) 34008)<\/span>\r\n<ul>\r\n \t<li><span style=\"font-size: 1em\">https:\/\/apod.nasa.gov\/apod\/ap170907.html<\/span><\/li>\r\n \t<li><span style=\"font-size: 1em\">https:\/\/apod.nasa.gov\/apod\/ap170823.html<\/span><\/li>\r\n \t<li><span style=\"font-size: 1em\">https:\/\/navbharattimes.indiatimes.com\/astro\/religion<\/span><span style=\"font-size: 1em\">-<\/span><span style=\"font-size: 1em\">and<\/span><span style=\"font-size: 1em\">-<\/span><span style=\"font-size: 1em\">spiritualism\/panchang\/panchang<\/span><span style=\"font-size: 1em\">-<\/span><span style=\"font-size: 1em\">24<\/span><span style=\"font-size: 1em\">-<\/span><span style=\"font-size: 1em\">october<\/span><span style=\"font-size: 1em\">-<\/span><span style=\"font-size: 1em\">2017<\/span><span style=\"font-size: 1em\">-<\/span><span style=\"font-size: 1em\">tuesday\/articleshow\/61183632.cms<\/span><\/li>\r\n \t<li><span style=\"font-size: 1em\">https:\/\/en.wikipedia.org\/wiki\/Panchangam<\/span><\/li>\r\n \t<li><span style=\"font-size: 1em\">https:\/\/en.wikipedia.org\/wiki\/Hindu_calendar<\/span><\/li>\r\n \t<li><span style=\"font-size: 1em\">https:\/\/hindunet.org\/hindu<\/span><span style=\"font-size: 1em\">_calendar\/<\/span><\/li>\r\n<\/ul>\r\n<div class=\"annotationLayer\"><\/div>","rendered":"<p>&nbsp;<\/p>\n<p><strong>1.\u00a0 Learning Outcomes<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">After studying this module, you should be able to<\/p>\n<ul>\n<li style=\"text-align: justify\">enumerate the various methods used to measure the solar surface temperature<\/li>\n<li style=\"text-align: justify\">discuss the Wien\u2019s displacement law in physics and its use in measuring solar temperature<\/li>\n<li style=\"text-align: justify\">explain the application of Stefan-Boltzmann law to the solar surface temperature using the luminosity and the radius of the Sun<\/li>\n<li style=\"text-align: justify\">describe how the fitting of black body curve to the observed solar spectrum yields the solar surface temperature<\/li>\n<li style=\"text-align: justify\">derive the temperature of the Sun using its observed colour index<\/li>\n<li style=\"text-align: justify\">explain why the temperatures derived using various methods do not agree with one another<\/li>\n<li style=\"text-align: justify\">describe the layers of the solar atmosphere and explain why they are seen except when the solar disc is covered<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><strong>2.\u00a0 Introduction<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\"><span style=\"text-align: initial;text-indent: 1em;font-size: 1em\">In the last module, Module 20, we discussed some basic parameters which characterize the Sun. The first parameter to be discussed was the distance of the Sun from the earth, a quantity called Astronomical Unit. This distance plays a key role in estimating the mass and luminosity of the Sun.\u00a0 We discussed the attempts made by ancient astronomers, using transits of planets in front of the solar disc to estimate the Sun\u2019s distance from the earth.\u00a0 We also discussed how they used a particular phase of the moon and moon\u2019s distance from the earth for this purpose. Then we discussed the modern method of finding this distance.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">Using the distance of the Sun, we could estimate the mass of the Sun by equating the centripetal force acting on the earth and the gravitational force of the Sun which holds earth in its orbit.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">Another parameter that could be found using the distance was the radius of the Sun. It is easy to find the angular diameter of the Sun and multiplying it with the distance of the Sun, the size of the Sun could be accurately calculated.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">Yet another important parameter, luminosity of the Sun, was also discussed.\u00a0 The energy falling per second on a square meter of a surface placed outside the earth\u2019s atmosphere normal to the rays of the Sun is called the solar constant. So, if we draw a sphere of radius equal to one AU centred on the earth, each square meter of its surface receives energy equal to the solar constant. Multiplying the total surface area of this sphere by the solar constant enables us to calculate the total energy emitted by the sun every second. That is the luminosity of the Sun. \u00a0Just to digress a bit, variations in the solar constant were also discussed since they may be important in connection with the weather and climate change on the earth and global warming we are witnessing today.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">An important data for the Sun is its surface temperature, or effective temperature, which we now discuss.<\/p>\n<p>&nbsp;<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-286 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_03-e1542619345257.jpg\" alt=\"\" width=\"1996\" height=\"2532\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_03-e1542619345257.jpg 1996w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_03-e1542619345257-236x300.jpg 236w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_03-e1542619345257-768x974.jpg 768w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_03-e1542619345257-807x1024.jpg 807w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_03-e1542619345257-65x82.jpg 65w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_03-e1542619345257-225x285.jpg 225w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_03-e1542619345257-350x444.jpg 350w\" sizes=\"auto, (max-width: 1996px) 100vw, 1996px\" \/> <img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-285 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_04-e1542619373381.jpg\" alt=\"\" width=\"1963\" height=\"2590\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_04-e1542619373381.jpg 1963w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_04-e1542619373381-227x300.jpg 227w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_04-e1542619373381-768x1013.jpg 768w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_04-e1542619373381-776x1024.jpg 776w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_04-e1542619373381-65x86.jpg 65w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_04-e1542619373381-225x297.jpg 225w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_04-e1542619373381-350x462.jpg 350w\" sizes=\"auto, (max-width: 1963px) 100vw, 1963px\" \/> <img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-284 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_05-e1542619403612.jpg\" alt=\"\" width=\"1971\" height=\"2730\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_05-e1542619403612.jpg 1971w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_05-e1542619403612-217x300.jpg 217w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_05-e1542619403612-768x1064.jpg 768w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_05-e1542619403612-739x1024.jpg 739w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_05-e1542619403612-65x90.jpg 65w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_05-e1542619403612-225x312.jpg 225w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_05-e1542619403612-350x485.jpg 350w\" sizes=\"auto, (max-width: 1971px) 100vw, 1971px\" \/> <img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-283 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_06-e1542619467545.jpg\" alt=\"\" width=\"1938\" height=\"2689\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_06-e1542619467545.jpg 1938w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_06-e1542619467545-216x300.jpg 216w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_06-e1542619467545-768x1066.jpg 768w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_06-e1542619467545-738x1024.jpg 738w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_06-e1542619467545-65x90.jpg 65w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_06-e1542619467545-225x312.jpg 225w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_06-e1542619467545-350x486.jpg 350w\" sizes=\"auto, (max-width: 1938px) 100vw, 1938px\" \/> <img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-282 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_07-e1542619564662.jpg\" alt=\"\" width=\"2004\" height=\"2301\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_07-e1542619564662.jpg 2004w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_07-e1542619564662-261x300.jpg 261w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_07-e1542619564662-768x882.jpg 768w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_07-e1542619564662-892x1024.jpg 892w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_07-e1542619564662-65x75.jpg 65w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_07-e1542619564662-225x258.jpg 225w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_07-e1542619564662-350x402.jpg 350w\" sizes=\"auto, (max-width: 2004px) 100vw, 2004px\" \/> <img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-281 size-full\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_08-e1542619591596.jpg\" alt=\"\" width=\"1988\" height=\"2186\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_08-e1542619591596.jpg 1988w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_08-e1542619591596-273x300.jpg 273w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_08-e1542619591596-768x844.jpg 768w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_08-e1542619591596-931x1024.jpg 931w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_08-e1542619591596-65x71.jpg 65w, 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src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_14-e1542619783590.jpg\" alt=\"\" width=\"1980\" height=\"2697\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_14-e1542619783590.jpg 1980w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_14-e1542619783590-220x300.jpg 220w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_14-e1542619783590-768x1046.jpg 768w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_14-e1542619783590-752x1024.jpg 752w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_14-e1542619783590-65x89.jpg 65w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_14-e1542619783590-225x306.jpg 225w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_14-e1542619783590-350x477.jpg 350w\" sizes=\"auto, (max-width: 1980px) 100vw, 1980px\" \/> <img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-274\" src=\"http:\/\/phyp06.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_15-e1542619801669.jpg\" alt=\"\" width=\"777\" height=\"184\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_15-e1542619801669.jpg 1988w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_15-e1542619801669-300x71.jpg 300w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_15-e1542619801669-768x182.jpg 768w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_15-e1542619801669-1024x242.jpg 1024w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_15-e1542619801669-65x15.jpg 65w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_15-e1542619801669-225x53.jpg 225w, https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-content\/uploads\/sites\/97\/2018\/11\/1523533673Module21Text_Page_15-e1542619801669-350x83.jpg 350w\" sizes=\"auto, (max-width: 777px) 100vw, 777px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p><strong><span style=\"font-size: 1em\">Suggested Readings<\/span><\/strong><\/p>\n<ul>\n<li><span style=\"font-size: 1em\">http:\/\/www.eurastro.de\/webpages\/MRSPECT.HTM<\/span><\/li>\n<li><span style=\"font-size: 1em\">http:\/\/kho.unis.no\/Eclipse\/index_Cor.html<\/span><\/li>\n<li><span style=\"font-size: 1em\">http:\/\/cseligman.com\/text\/sun\/sunatmosphere.htm<\/span><\/li>\n<li><span style=\"font-size: 1em\">http:\/\/iopscience.iop.org\/article\/10.1086\/301490\/fulltext\/<\/span><\/li>\n<li><span style=\"font-size: 1em\">http:\/\/www.vendian.org\/mncharity\/dir3\/starcolor\/details.html<\/span><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><span style=\"font-size: 1em\">Ballestero (Ballesteros, F.J. (2012). &#8220;New insights into black bodies &#8220;. EPL (Europhysics Letters) 97 (2012) 34008)<\/span><\/p>\n<ul>\n<li><span style=\"font-size: 1em\">https:\/\/apod.nasa.gov\/apod\/ap170907.html<\/span><\/li>\n<li><span style=\"font-size: 1em\">https:\/\/apod.nasa.gov\/apod\/ap170823.html<\/span><\/li>\n<li><span style=\"font-size: 1em\">https:\/\/navbharattimes.indiatimes.com\/astro\/religion<\/span><span style=\"font-size: 1em\">&#8211;<\/span><span style=\"font-size: 1em\">and<\/span><span style=\"font-size: 1em\">&#8211;<\/span><span style=\"font-size: 1em\">spiritualism\/panchang\/panchang<\/span><span style=\"font-size: 1em\">&#8211;<\/span><span style=\"font-size: 1em\">24<\/span><span style=\"font-size: 1em\">&#8211;<\/span><span style=\"font-size: 1em\">october<\/span><span style=\"font-size: 1em\">&#8211;<\/span><span style=\"font-size: 1em\">2017<\/span><span style=\"font-size: 1em\">&#8211;<\/span><span style=\"font-size: 1em\">tuesday\/articleshow\/61183632.cms<\/span><\/li>\n<li><span style=\"font-size: 1em\">https:\/\/en.wikipedia.org\/wiki\/Panchangam<\/span><\/li>\n<li><span style=\"font-size: 1em\">https:\/\/en.wikipedia.org\/wiki\/Hindu_calendar<\/span><\/li>\n<li><span style=\"font-size: 1em\">https:\/\/hindunet.org\/hindu<\/span><span style=\"font-size: 1em\">_calendar\/<\/span><\/li>\n<\/ul>\n<div class=\"annotationLayer\"><\/div>\n","protected":false},"author":4,"menu_order":16,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":["prof-v-b-bhatia"],"pb_section_license":""},"chapter-type":[],"contributor":[58],"license":[],"class_list":["post-273","chapter","type-chapter","status-publish","hentry","contributor-prof-v-b-bhatia"],"part":3,"_links":{"self":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-json\/pressbooks\/v2\/chapters\/273","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-json\/wp\/v2\/users\/4"}],"version-history":[{"count":1,"href":"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-json\/pressbooks\/v2\/chapters\/273\/revisions"}],"predecessor-version":[{"id":287,"href":"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-json\/pressbooks\/v2\/chapters\/273\/revisions\/287"}],"part":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-json\/pressbooks\/v2\/parts\/3"}],"metadata":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-json\/pressbooks\/v2\/chapters\/273\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-json\/wp\/v2\/media?parent=273"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-json\/pressbooks\/v2\/chapter-type?post=273"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-json\/wp\/v2\/contributor?post=273"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/phyp06\/wp-json\/wp\/v2\/license?post=273"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}