八個不同年齡的疏散星團之光度研究

The Photometric Study of Eight Open Clusters with Different Ages

蕭翔耀(Hsiang-Yao Hsiao)

指導教授 ： 傅學海 教授

國立臺灣師範大學/理學院/地球科學系/碩士(2006年)

摘要

本研究針對八個不同年齡的疏散星團，IC348、NGC 2244、NGC 2301、NGC 5385、Czernik 10、NGC 2395、NGC 663及 King 6，使用中央大學鹿林前山天文台的一公尺望遠鏡，進行CCD Johnson光度系統觀測，以取得星團的光度、星際紅化、星際吸收及距離與年齡等參數。其中對五個疏散星團(IC348，NGC 2244，NGC 2301，NGC 5385及Czernik 10)進行UBV光度三波段觀測，而其他三個星團則使用BV光度觀測。對於IC348，紅化值約為E(B-V) = 0.8，距離約為320秒差距，而估計其年齡約在4百萬年到6.3百萬年之間。NGC 2244，紅化值約為0.45，距離約為1320秒差距，年齡估計約4百萬年到一千三百萬年間。NGC 2301的紅化較為小，約0.08，而距離與年齡分別約為790秒差距及1.6百萬年到2.5百萬年間。Czernik10紅化值約0.6，距離約1690秒差距，年齡大約介於16億年到63億年間。而King 6及NGC 663其紅化值分別約0.6及0.65，距離約750秒差距及3000秒差距，而年齡介於二億年至3.2億年及一千兩百萬年至兩千五百萬年間。至於對於疏散星團NGC 2395及NGC 5385，因為其星色星等圖（CMD）過於分散，我們無法得到任何資訊，有篇2004年的研究指出NGC 5385並非是個疏散星團，在我們的ＵＢＶ光度測量的資料來看，NGC 5385也偏向於不是個疏散星團。對於NGC 2395也有待於未來更多資訊以進行判斷。

關鍵字

疏散星團

並列摘要

The (U)BV CCD photometry of eight open clusters with different ages and
distance are study. Five open clusters (IC348, NGC 2244, NGC 2301, NGC 5385, and
Czernik 10) were observed with U, B, and V photometry, and the other three open
clusters (NGC 2395, King 6 and NGC 663) only with B and V photometry. For IC348,
the reddening E(B-V) is about 0.8, and its distance and age are 320 pc and 4.0-6.3 M
yrs, respectively; The reddening of NGC 2244 is about 0.45, and its distance and age
are 1320 pc and 4-13 Myrs, respectively. The reddening of NGC 2301 is about 0.08,
and its distance and age are 790 pc and 1.6-2.5 Myrs. Accordingly, the reddening of
Czernik10 is about 0.6, and its distance and age are 1690 pc and 1.6-6.3 Gyrs,
respectively. The reddening of King 6 is about 0.6, and its distance and age are 750 pc
and 200-320 Myrs, respectively. The reddening of NGC 663 is about 0.65, and its
distance and age are 3000 pc and 12-25 Myrs, respectively. There is no information
could be gotten about NGC 2395 from its’ CMD. So is NGC 5385 from CMD; A
study in 2004 showed that NGC 5385 is probably not an open cluster. NGC 5385 also
indicate that is probably not an open cluster our data of UBV photometry.

並列關鍵字

open cluster

參考文獻

Ann, H. B. et al. 2002, AJ, 123, 905.

Bica, E. et al. 2001, A&A, 366, 827B.

Blaauw, A. 1964, ARA&A, 2, 213B.

Czernik, 1966, AcA, 16, 93C

Dias, et al. 2006, http://www.astro.iag.usp.br/~wilton/