IC Catalog
5596 objects in the IC catalog
Βαθύς Ουρανός
Author
John Louis Emil Dreyer (1852-1926)
Year
1895, 1908
Αντικείμενα
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.
Αντικείμενα
| Όνομα | Τύπος | RA | Απόκλιση | Μέγ. | Αστερισμός | Ενέργειες |
|---|
Σχετικά με δεδομένα βαθέος ουρανού
Πηγή δεδομένων
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
Φωτομετρικά συστήματα
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.
Κλίμακα μεγέθους
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:
\[m_1 - m_2 = -2.5 \times \log_{10}\left(\frac{F_1}{F_2}\right)\]
όπου m είναι το μέγεθος και F είναι η ροή. Μικρότερο μέγεθος = λαμπρότερο αντικείμενο.
Δείκτης χρώματος (B-V)
Ο χρωματικός δείκτης B-V υποδεικνύει το χρώμα και τη θερμοκρασία του αντικειμένου:
\[B - V = m_B - m_V\]
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: Μετατροπή χρώματος
Σημειογραφία μεγέθους
Each magnitude value is marked with (V) for V-band or (B) for B-band to indicate the photometric system used.
Οδηγός ορατότητας:
• Όριο γυμνού ματιού: ~6.0 mag
• Κιάλια: ~10.0 mag
• Μικρό τηλεσκόπιο (4"): ~12.0 mag
• Μεσαίο τηλεσκόπιο (8"): ~14.0 mag
Σύστημα συντεταγμένων
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).