NGC Catalog - Skylook.org

NGC Catalog

8373 objects in the NGC catalog

Novi opći katalog

Author

John Louis Emil Dreyer (1852-1926)

Year

1888

Objekti

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

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.

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Ime Vrsta RA Dek Sjaj Zviježđe Akcije

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Izvor podataka

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

Fotometrijski sustavi

V-band (Visual): Johnson V filtar centriran na ~550nm (žuto-zeleno), odgovara vršnoj osjetljivosti oka. Ovo je standardni astronomski sustav magnitudа.

B-band (Blue): Johnson B filtar centriran na ~440nm (plavo svjetlo). Koristi se kada V magnituda nije dostupna.

Ljestvica sjaja

Astronomska ljestvica magnitudа je logaritamska. Svaki korak magnitude predstavlja omjer sjaja od ~2,512. Formula:

\[m_1 - m_2 = -2.5 \times \log_{10}\left(\frac{F_1}{F_2}\right)\]

gdje je m sjaj, a F tok. Niži sjaj = svjetliji objekt.

Indeks boje (B-V)

Indeks boje B-V označava boju i temperaturu objekta:

\[B - V = m_B - m_V\]

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: Pretvorba boje

Oznaka sjaja

Svaka vrijednost magnitude označena je s (V) za V-pojas ili (B) za B-pojas kako bi se naznačio korišteni fotometrijski sustav.

Vodič vidljivosti:
• Granica golim okom: ~6,0 mag
• Dvogledi: ~10,0 mag
• Mali teleskop (4"): ~12,0 mag
• Srednji teleskop (8"): ~14,0 mag

Koordinatni sustav

Right Ascension (RA): Celestial longitude in hours:minutes:seconds (0h to 24h).

Declination (Dec): Celestial latitude in degrees:arcminutes:arcseconds (-90 to +90 degrees).

Sve koordinate su u epohi J2000.0 (standardni referentni okvir za godinu 2000).