Fog catalog

In astronomy, a nebula catalog is a systematic directory of objects that appear nebulous , such as gas nebulae , very dense star clusters or galaxies . Such a catalog can

extend over a larger part of the sky, e.g. B. its north or south half ,
over a star formation region or a galaxy cluster
or only capture objects up to a certain brightness .

The first such catalogs appeared in the 17th century, a few decades after the invention of the telescope . Many of the objects seen freely as planar turned out to be a tight cluster of stars, while others remained planar in the telescope and were called nebulae until around 1900 . The word was retained in several proper names of galaxies that used to be called spiral nebulae , e.g. B. in the Andromeda nebula (galaxy M 31 ) or in the triangular nebula M 33 .

Today, the term nebula is mainly used for interstellar gas and dust clouds that appear either bright or as dark nebulae.

The first systematic directory of foggy celestial objects is the Messier catalog drawn up by Charles Messier in 1774. Another important directory is the New General Catalog (NGC) by Johan Dreyer (1888). In addition to gas and dust nebulae, both contain galaxies and star clusters and are still widely used today.

Messier catalog and NGC

The first fog catalogs come from William Herschel and some of his contemporaries. The best known of the early nebula catalogs is the list of around 100 celestial objects published by Charles Messier around 1870 and soon to be called the Messier catalog , which was later expanded to 109 objects.

Johan Dreyer's New General Catalog (NGC), comprising 7,840 objects, was created at the end of the 19th century . To this day, it is the standard directory of star clusters, galactic nebulae and galaxies, but since then numerous catalogs reaching into greater distances have been compiled and published.

Newer fog catalogs

Most of the catalogs created since the NGC only include individual categories of astronomical objects, so-called special catalogs for

Open clusters or globular clusters
Galactic nebulae (emission and reflection nebulae, planetary and dark nebulae)
Galaxies or galaxy clusters

Catalogs for open and spherical clusters

the Collinder catalog (1931, 471 items)
the OCL catalog (1983, 1112 items)
the catalog of the Lund observatory (1987, 1150 objects)

Catalogs for galactic nebulae

Barnard catalog (1927), 321 photographically captured dark clouds
Cederblad Catalog (1946) Studies of Bright Diffuse Galactic Nebulae , Lund Observatory
Sharpless catalog (1959), 312 emission nebulae north of δ = −27 °
A.Acker ( ESO 1992), Catalog of Galactic Planetary Nebulae (1,143 properties )
Lumsden catalog (2002), approx. 3000 nebulae, MNRAS volume 336
Peretto-Fuller Catalog (2009), approx.11,000 nebulae, Astrophysical Journal Volume 205

Galaxies Catalogs

Shapley-Ames catalog from 1932 with 1250 objects up to brightness 13.2
Revised Shapley-Ames-Calalog (RSA) from 1982
Reference Catalog of Bright Galaxies with 23,000 galaxies in the RC3 edition
Principal Galaxies Catalog (PGC) from 1989 with over 70,000 galaxies
Millennium Galaxy Catalog (MGC)
Sloan Digital Sky Survey with 930,000 galaxies, created on the 2.5m Apache Point telescope with around 10,000 images from a 150 megapixel camera.
- in two parts: SDSS-I (2000-2005) and SDSS-II (2005-2008)

literature

Günter D. Roth : Astronomie-Geschichte , Kosmos-Verlag, Stuttgart 1987
Susanne Friedrich et al .: Handbook Astronomy , Chapter "Gas" and "Galactic Nebula". 560 p., Oculum-Verlag, Erlangen 2015
Arnold Hanslmeier : Introduction to Astronomy and Astrophysics . 3rd edition, 624 p., Verlag Springer / Spektrum, Berlin-Heidelberg 2014
Hans-Heinrich Vogt : Outline of the astronomy . 6th edition , Wiley-VCH-Verlag 2012
Hans Vehrenberg : My Messier book (with another 260 celestial objects). Treugesell-Verlag, Düsseldorf 1970