No messier in Carina using nightsky printout

[nobby2 (Neil)]

Can someone set me straight. I am usung the nightsky program to print out a star chart of carina constellation and noticed they are given the numbers n4349, n4103, n3293 and i cant find those numbers in the messier catalogue or in my atlas of the southern night sky book?
On closer look there is a match with ngc numbers on some of the n numbers.

[Barrykgerdes]

Those are all ngc items. Some catalogues will find them if you just enter n and the number but normally you need to enter the full number in a search.

By the way there are no Messier objects that far south only ngc's

Barry

[madbadgalaxyman (Robert)]

I agree, it seems that the n on your star chart stands for NGC;

A quick reference for what each NGC or IC obect is, is the NGC/IC project website:
http://www.ngcicproject.org/pubdb.htm

NGC 3293 is an open cluster in Carina

NGC 4349 is an open cluster in Crux

NGC 4103 is an open cluster in Crux

The star atlases vary greatly in the number of deep sky objects thay show. Some of them show only the bright or fairly bright objects in a constellation, while others (especially the software star charts) can plot hundreds of thousands, or even millions, of non-stellar objects.

You will see plenty of sources where NGC is shortened to N, for example,
instead of the galaxy NGC 253, someone might write N253 or N0253.

The NGC and the IC catalogs contain most of the visually obvious non-stellar objects in our sky, as they were based on the sky surveys done by the 19th and 18th century observers, notably the Herschels.

However, these people missed a good number of fairly obvious southern objects, and also they missed a lot of low surface brightness galaxies and very extended nebulae which are difficult to see - but nonetheless still visible - for modern deep sky observers.
So then one has to access objects in a lot of more exotic catalogs such as UGC (for galaxies), and RCW (for nebulae) and ESO (for some moderately bright southern galaxies missing in the NGC and IC catalogs)

We have a member called glenc who is a master of the history of these catalogs, while I am more specialized in the obscure catalogs of galaxies.

You need good tools that show adequate stars for finding the objects you wish to see, and which have enough deep sky objects plotted.
Others are more qualified than me to recommend sky plotting tools for people who are at the beginning to intermediate amateur level.

[mithrandir (Andrew)]

You will also find that which constellation an object falls in depends on the date. The boundaries as originally defined in 1930 and based on B1875 co-ordinates followed lines of constant RA and Dec. Precession means the boundaries today are not so simple. Vizier catalog VI/49 has files of co-ordiates for the boundaries. The B1875 version has 1565 rows defining the constellation corners. The J2000 version has 53684 rows to approximate the precessed boundaries.

Proper motion can also change into which constellation an object falls.

The most recent version of the NGC+IC catalog lists 60 objects as being in Carina.