IC Catalog
5596 objects in the IC catalog
索引星表
Author
John Louis Emil Dreyer (1852-1926)
Year
1895, 1908
天体
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.
筛选天体
| 名称 | 类型 | 赤经 | 赤纬 | 星等 | 星座 | 操作 |
|---|
关于深空数据
数据来源
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
测光系统
V-band (Visual): 约翰逊V滤光片，中心波长约550nm（黄绿色），与人眼峰值灵敏度匹配。这是标准天文星等系统。
B-band (Blue): 约翰逊B滤光片，中心波长约440nm（蓝光）。在V星等不可用时使用。
星等标度
天文星等尺度是对数的。每个星等步长代表约2.512倍的亮度比。星等差与亮度比的关系公式为：
\[m_1 - m_2 = -2.5 \times \log_{10}\left(\frac{F_1}{F_2}\right)\]
其中m为星等，F为流量。星等越低=天体越亮。
色指数（B-V）
B-V色指数表示天体的颜色和温度：
\[B - V = m_B - m_V\]
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: 颜色转换
星等表示法
每个星等值标记(V)表示V波段，或(B)表示B波段，以指示所用测光系统。
可见度指南：
• 肉眼极限：约6.0等
• 双筒望远镜：约10.0等
• 小型望远镜（10厘米）：约12.0等
• 中型望远镜（20厘米）：约14.0等
坐标系
Right Ascension (RA): Celestial longitude in hours:minutes:seconds (0h to 24h).
Declination (Dec): Celestial latitude in degrees:arcminutes:arcseconds (-90 to +90 degrees).
所有坐标均采用J2000.0历元（2000年标准参考框架）。