NGC 884 (也稱為英仙座χ )是一個位於英仙座的疏散星團,距離地球7,600[2]。它位於和NGC 869組成的雙星團的最東端。NGC 869和884通常各別被稱為英仙座h和χ[4]。這個星團的年齡估計已有為1,250萬年[2]。這兩個星團有物理上的關聯性,估計相距只有數百光年,都是星協英仙座OB1的成員。喜帕恰斯是最早記錄下這兩個星團的人,但很可能遠古時代早就已經知道這兩個星團。
雙星團是業餘天文學家的最愛。像這種明亮的星團通常是用小望遠鏡拍攝或觀察到的。但雙星團簡單到肉眼就能在英仙座和仙后座之間看見,在冬天的銀河中也是一個明亮的區域。雙星團也被收錄在專供業餘天文觀測使用的科德韋爾深空天體表[3]。在小望遠鏡中,星團以美麗的星形組合出現在富饒的恆星場中。該星團以明亮的藍色恒星為主,還擁有一些橙色恒星,豐富了人們的視覺興趣。兩個星團一起為低倍率的視野提供了壯觀的景色。
參考資料
- ^ 1.0 1.1 1.2 1.3 [ NGC 884]. SIMBAD. 斯特拉斯堡天文資料中心. [2006-12-22].
- ^ 2.0 2.1 2.2 2.3 2.4 Kharchenko; et al. Astrophysical Parameters of Galactic Open Clusters. Astronomy and Astrophysics. 2005, 438 (3): 1163–1173 [2020-10-19]. Bibcode:2005A&A...438.1163K. arXiv:astro-ph/0501674
. doi:10.1051/0004-6361:20042523. (原始内容存档于2016-02-21).
- ^ 3.0 3.1 O'Meara, Stephen James. The Caldwell Objects. Cambridge University Press. 2002. ISBN 978-0-521-82796-6.
- ^ Some confusion surrounds what Bayer intended by these designations. It is sometimes claimed that Bayer could not have resolved the pair into two patches of nebulosity, and that Chi refers to the Double Cluster and h to a nearby star; see Stephen James O'Meara and Daniel W.E. Green, 2003, "The Mystery of the Double Cluster", Sky and Telescope, Vol. 105, No. 2 (February 2003), p. 116–119. Bayer's Uranometria chart for Perseus does not show them as nebulous objects, but his chart for Cassiopeia does, and they are described as Nebulosa Duplex in Schiller's Coelum Stellatum Christianum, which was assembled with Bayer's help; see Morton Wagman, Lost Stars, McDonald & Woodward, 2003, ISBN 0939923785, p. 240.
维基共享资源上的相關多媒體資源:NGC 884