A型主序星
Multi tool use
一位藝術家印象中的天狼星A和B，天狼A是兩顆中較大的那一顆恆星。
A型主序星(AV星)是光譜為A，亮度為V，在主序帶（氫燃燒）上恆星。這些恆星的定義是在恆星光譜类型A和光度级V。恆星光譜上有強烈的氫的巴耳末吸收譜線 [1][2]，它們的質量從太陽的1.4倍至2.1倍太陽質量，表面溫度在7,600至10,000K [3]。
明亮的和附近的A型主序星的例子包括牛郎星(A7 V)、天狼星A(A1 V)和織女星(A0 V)[4]。
行星
A型主序星恒星都是年轻的（通常是几亿年），并发射出比单独的恒星发射的红外辐射更多的额外红外辐射。这些过剩的红外辐射的原因是来自于岩屑盤的红外辐射，在岩屑盤中行星形成[5]。
相關條目
參考資料
^ Stellar Spectral Types, entry at hyperphysics.phy-astr.gsu.edu, accessed on line June 19, 2007.
^ "An Introduction to Modern Astrophysics" by B.W Caroll and D.A Ostlie 1996 edition, chapter 8
^ Empirical bolometric corrections for the main-sequence, G. M. H. J. Habets and J. R. W. Heintze, Astronomy and Astrophysics Supplement 46 (November 1981), pp. 193–237, Tables VII and VIII.
^ SIMBAD, entries on Sirius A and Vega, accessed June 19, 2007.
^ Song, Inseok; 等, M-Type Vega-like Stars, The Astronomical Journal, 2002, 124 (1): 514–518, Bibcode:2002AJ....124..514S, arXiv:astro-ph/0204255, doi:10.1086/341164
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