IC Catalog
5596 objects in the IC catalog
索引星表
Author
John Louis Emil Dreyer (1852-1926)
Year
1895, 1908
天體
5386
The Index Catalogue (IC) is an astronomical catalogue compiled by John Louis Emil Dreyer and published in two parts in 1895 and 1908 as supplements to the New General Catalogue. The IC contains 5,386 objects that were discovered after the NGC was published, continuing the systematic cataloging of deep-sky objects.
Data Sources
- OpenNGC Database - Modern digitized version with corrections and updates
- Wikipedia - Index Catalogue - Historical background and detailed information
Objects are numbered IC 1 through IC 5386. The IC was created to supplement the NGC with newly discovered objects and corrections.
篩選天體
| 名稱 | 類型 | 赤經 | 赤緯 | 星等 | 星座 | 操作 |
|---|
關於深空數據
資料來源
Deep sky object data comes from the OpenNGC database by Mattia Verga. Coordinates, magnitudes, and object classifications are sourced from authoritative astronomical catalogs including NGC, IC, Messier, and Caldwell. Source repository: OpenNGC database
測光系統
V-band (Visual): Johnson V 濾鏡的中心波長約為 550nm（黃綠光），對應人眼靈敏度的峰值。這是標準的天文星等系統。
B-band (Blue): Johnson B 濾鏡的中心波長約為 440nm（藍光）。在沒有 V 星等時使用。
星等尺度
天文星等尺度是對數式的。每一級星等代表約 2.512 倍的亮度比。將星等差與亮度比關聯起來的公式為：
\[m_1 - m_2 = -2.5 \times \log_{10}\left(\frac{F_1}{F_2}\right)\]
其中 m 為星等，F 為通量。星等越低 = 天體越亮。
色指數（B-V）
B-V 色指數表示天體的顏色與溫度：
\[B - V = m_B - m_V\]
Typical values: blue objects have negative B-V, white objects are near 0, yellow objects are near 0.6, and red objects are above 1.0. Reference: 色彩轉換
星等表示法
每個星等值都以 (V) 表示 V 波段或以 (B) 表示 B 波段，以指示所使用的測光系統。
可見度指南：
• 肉眼極限：約 6.0 星等
• 雙筒望遠鏡：~10.0 星等
• 小型望遠鏡（4"）：~12.0 星等
• 中型望遠鏡（8"）：~14.0 星等
坐標系
Right Ascension (RA): Celestial longitude in hours:minutes:seconds (0h to 24h).
Declination (Dec): Celestial latitude in degrees:arcminutes:arcseconds (-90 to +90 degrees).
所有座標均採用 J2000.0 曆元（2000 年的標準參考框架）。