NGC Catalog
8373 objects in the NGC catalog
新总星表
Author
John Louis Emil Dreyer (1852-1926)
Year
1888
天体
7840
The New General Catalogue of Nebulae and Clusters of Stars (NGC) is an astronomical catalogue compiled by John Louis Emil Dreyer in 1888. It contains 7,840 deep-sky objects and is one of the most comprehensive catalogs of its kind. The NGC expanded upon previous catalogs and remains a fundamental reference for astronomers today.
Data Sources
- OpenNGC Database - Modern digitized version with corrections and updates
- Wikipedia - New General Catalogue - Historical background and detailed information
Objects are numbered NGC 1 through NGC 7840. Many objects have been reclassified or found to be duplicate entries since the original catalog was published.
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）。