The Henize Catalogue of SMC Emission Nebulae
Back to Index of Max's Deep Sky Objects In The Magellanic Clouds
By Max Gardner AM
In 1956 Karl Henize published the results of an extensive survey of both Magellanic Clouds for emission line objects, stars and nebulae. Five catalogues of objects were published, three for the LMC and two for the SMC. The file I present here deals with just one Henize list, that listing the LMC emission nebulae. The coordinates are now given for equinox 2000, with higher precision. The various data fields are explained as follows:
Object Name: The full name of the first entry, according to Henize's system, is LHa120-N1. "L" refers to the Lamont-Hussey Observatory of the University of Michigan; "Ha" means the Hydrogen-alpha emission line, the key signature line used in the survey; "120" refers to the plate number (objective prism plate) for the LMC; "N" labels the object as a nebula, as distinct from a star (label "S"). Some of the more complex nebulae are subdivided, using the letters A,B,C etc to indicate related knots of nebulosity within the complex.
NGC number: Given where known.
GSC number: Given where there is no uncertainty.
Position for J2000: Adopted from one of several sources.
Code:
- A = USNO-A2.0 catalogue
- B = BSDL catalogue (Astron.J. 117,238, 1999)
- E = Estimated by MM
- G = Guide Star Catalogue
- HZ = K. Henize (1956)
Dimensions: Henize gave dimensions for his nebulae, but point source ones, d <15", are generally blank. When one compares the values given in a recent BSDL catalogue, based on scans of big Schmidt plates, the more modern values are generally larger. Generally, but not always.
The big Schmidts can record fainter outlying portions of many nebulae which were invisible on Henize's plates. I surmise that this is the reason for the discordance. I have found it worth recording both sets of dimensions, so that the user may decide for himself which is more relevant.
Notes: Explanatory notes are given at the end of the table. Some are copied from Henize's 1956 paper, as an aid to identification.
References: Henize, K.G.1956, Astrophys. J. Suppl. 2,315 Monet, D. et al 1998. USNO-A2.0 astrometric catalogue. USNO, Flagstaff
The catalogue to accompany Max's article is available as a PDF file here:
https://www.asnsw.com/content.cfm?page_id=1342126¤t_category_code=21965
