Caldwell Catalog
109 objects in the Caldwell catalog
Caldwell Catalog
Author
Sir Patrick Moore (1923-2012)
Year
1995
பொருட்கள்
109
The Caldwell catalog is an astronomical catalog of 109 star clusters, nebulae, and galaxies for observation by amateur astronomers. It was compiled by Sir Patrick Alfred Caldwell-Moore (Patrick Moore) and published in 1995. The catalog complements the Messier catalog by including bright deep-sky objects visible from both hemispheres that were not included in Messier's original list.
Data Sources
- AstroPixels Caldwell Catalog - Complete reference with detailed information
- OpenNGC Database - Cross-referenced with NGC/IC designations
Objects are numbered C1 through C109. Unlike the Messier catalog, the Caldwell catalog includes objects visible from both northern and southern hemispheres.
பொருட்கள்
| பெயர் | NGC/IC | வகை | RA | Dec | Mag | நட்சத்திர மண்டலம் | Actions |
|---|
ஆழ்வான வானம் தரவு பற்றி
Data Source
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
Photometric Systems
V-band (Visual): Johnson V filter centered at ~550nm (yellow-green), matching peak sensitivity of human eye. This is the standard astronomical magnitude system.
B-band (Blue): Johnson B filter centered at ~440nm (blue light). Used when V magnitude is unavailable.
Magnitude Scale
The astronomical magnitude scale is logarithmic. Each magnitude step represents a brightness ratio of ~2.512x. The formula relating magnitude difference to brightness ratio is:
\[m_1 - m_2 = -2.5 \times \log_{10}\left(\frac{F_1}{F_2}\right)\]
where m is magnitude and F is flux. Lower magnitude = brighter object.
Color Index (B-V)
The B-V color index indicates object color and temperature:
\[B - V = m_B - m_V\]
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: Color Conversion
Magnitude Notation
Each magnitude value is marked with (V) for V-band or (B) for B-band to indicate the photometric system used.
Visibility Guide:
• Naked eye limit: ~6.0 mag
• Binoculars: ~10.0 mag
• Small telescope (4"): ~12.0 mag
• Medium telescope (8"): ~14.0 mag
ஆயத்தொலைவு முறை
Right Ascension (RA): Celestial longitude in hours:minutes:seconds (0h to 24h).
Declination (Dec): Celestial latitude in degrees:arcminutes:arcseconds (-90 to +90 degrees).
All coordinates are in the J2000.0 epoch (standard reference frame for year 2000).