如果說星系是銀河系……如果說恆星系是開普勒442a。 其實，只要對天文有所瞭解，也知道開普勒尋星是怎麼回事，這兩個問題都很容易回答。前者，這顆星距離地球1100光年，很明顯在銀河系之內。後者，開普勒尋星說白了就是觀測恆星的光變曲線，透過其變化來觀測可能存在的地外行星。中心恆星命名為開普勒-XXXa，如果發現了行星，依次用b、c、d……來命名。 我試著在網路上搜索了“開普勒-442a”這個關鍵詞，很遺憾，風頭全被他的行星搶走了。其實也難怪，因為開普勒尋星的目標都集中在質量和太陽相仿的主序星，一顆質量和太陽類似但是距離達到1100光年，其亮度恐怕十等都不到，自然也不會有任何的名氣。 在文獻庫搜尋了學術論文，發現一篇命中結果： 標題：“VALIDATION OF 12 SMALL KEPLER TRANSITING PLANETS IN THE HABITABLE ZONE”（確認十二顆宜居帶內的小的開普勒行星） ASTROPHYSICAL JOURNAL 卷:800 期:2 文獻號:99 DOI:10.1088/0004-637X/800/2/99 出版年:FEB 20 2015 摘要：“We present an investigation of 12 candidate transiting planets from Kepler with orbital periods ranging from 34 to 207 days, selected from initial indications that they are small and potentially in the habitable zone (HZ) of their parent stars. Few of these objects are known. The expected Doppler signals are too small to confirm them by demonstrating that their masses are in the planetary regime. Here we verify their planetary nature by validating them statistically using the BLENDER technique, which simulates large numbers of false positives and compares the resulting light curves with the Kepler photometry. This analysis was supplemented with new follow-up observations (high-resolution optical and near-infrared spectroscopy, adaptive optics imaging, and speckle interferometry), as well as an analysis of the flux centroids. For 11 of them (KOI-0571.05, 1422.04, 1422.05, 2529.02, 3255.01, 3284.01, 4005.01, 4087.01, 4622.01, 4742.01, and 4745.01) we show that the likelihood they are true planets is far greater than that of a false positive, to a confidence level of 99.73% (3 sigma) or higher. For KOI-4427.01 the confidence level is about 99.2% (2.6 sigma). With our accurate characterization of the GKM host stars, the derived planetary radii range from 1.1 to 2.7R(circle plus). All 12 objects are confirmed to be in the HZ, and nine are small enough to be rocky. Excluding three of them that have been previously validated by others, our study doubles the number of known rocky planets in the HZ. KOI-3284.01 (Kepler-438b) and are the planets most similar to the Earth discovered to date when considering their size and incident flux jointly.”（我就不翻譯了，注意最後一句） 說來慚愧，復旦並沒有開始天文系，所以沒有購買天文類外文期刊的版權。不過我想，如果樓主真有刨根問底的熱情，我想已經知道該怎麼做了。找到開設天文專業學校的同學或者朋友，讓他們幫忙下載這一篇文章。這是新聞報道的根本來源，其中肯定系統全面地介紹了行星和其環繞恆星的基本引數。 ------------- 如果我回答對你有幫助，請關注我一下。或有其他問題也可以關注我，給我發私信
如果說星系是銀河系……如果說恆星系是開普勒442a。 其實，只要對天文有所瞭解，也知道開普勒尋星是怎麼回事，這兩個問題都很容易回答。前者，這顆星距離地球1100光年，很明顯在銀河系之內。後者，開普勒尋星說白了就是觀測恆星的光變曲線，透過其變化來觀測可能存在的地外行星。中心恆星命名為開普勒-XXXa，如果發現了行星，依次用b、c、d……來命名。 我試著在網路上搜索了“開普勒-442a”這個關鍵詞，很遺憾，風頭全被他的行星搶走了。其實也難怪，因為開普勒尋星的目標都集中在質量和太陽相仿的主序星，一顆質量和太陽類似但是距離達到1100光年，其亮度恐怕十等都不到，自然也不會有任何的名氣。 在文獻庫搜尋了學術論文，發現一篇命中結果： 標題：“VALIDATION OF 12 SMALL KEPLER TRANSITING PLANETS IN THE HABITABLE ZONE”（確認十二顆宜居帶內的小的開普勒行星） ASTROPHYSICAL JOURNAL 卷:800 期:2 文獻號:99 DOI:10.1088/0004-637X/800/2/99 出版年:FEB 20 2015 摘要：“We present an investigation of 12 candidate transiting planets from Kepler with orbital periods ranging from 34 to 207 days, selected from initial indications that they are small and potentially in the habitable zone (HZ) of their parent stars. Few of these objects are known. The expected Doppler signals are too small to confirm them by demonstrating that their masses are in the planetary regime. Here we verify their planetary nature by validating them statistically using the BLENDER technique, which simulates large numbers of false positives and compares the resulting light curves with the Kepler photometry. This analysis was supplemented with new follow-up observations (high-resolution optical and near-infrared spectroscopy, adaptive optics imaging, and speckle interferometry), as well as an analysis of the flux centroids. For 11 of them (KOI-0571.05, 1422.04, 1422.05, 2529.02, 3255.01, 3284.01, 4005.01, 4087.01, 4622.01, 4742.01, and 4745.01) we show that the likelihood they are true planets is far greater than that of a false positive, to a confidence level of 99.73% (3 sigma) or higher. For KOI-4427.01 the confidence level is about 99.2% (2.6 sigma). With our accurate characterization of the GKM host stars, the derived planetary radii range from 1.1 to 2.7R(circle plus). All 12 objects are confirmed to be in the HZ, and nine are small enough to be rocky. Excluding three of them that have been previously validated by others, our study doubles the number of known rocky planets in the HZ. KOI-3284.01 (Kepler-438b) and are the planets most similar to the Earth discovered to date when considering their size and incident flux jointly.”（我就不翻譯了，注意最後一句） 說來慚愧，復旦並沒有開始天文系，所以沒有購買天文類外文期刊的版權。不過我想，如果樓主真有刨根問底的熱情，我想已經知道該怎麼做了。找到開設天文專業學校的同學或者朋友，讓他們幫忙下載這一篇文章。這是新聞報道的根本來源，其中肯定系統全面地介紹了行星和其環繞恆星的基本引數。 ------------- 如果我回答對你有幫助，請關注我一下。或有其他問題也可以關注我，給我發私信