Galaxies in Leo Minor

The "Amateur Deep Field"

Wolfgang Steinicke




The "Amateur Deep Field" contains all known galaxies in the northern constellation Leo Minor from various catalogues. In addition 153 new objects are included, so the Leo Minor Galaxy Catalogue lists 1379 objects. All data, including precise positions (accuracy 1-2"), magnitudes, sizes, position angles, types and cross identifications are presented. A large amount of these data are determined for the first time. This project originates from a suggestion of the Fachgruppe Deep Sky of the german Vereinigung der Sternfreunde.

Version: 23.03.1998

Table of contents

1. Introduction

2. Content and structure of the catalogue

2.1 Coordinates

2.2 Magnitude, sizes, position angle and type

2.3 Identifications and remarks

3. Literature

4. ASCII-Daten

1. Introduction

The idea of surveying defined areas of the sky is not new, but only amateurs would choose a specific constellation and not a mere rectangular portion of the sky for this task. The "feeling", being in a certain constellation is not very scientific, but can be very fascinating. Years ago I listed all galaxies in Lyra, which is certainly not a very area for hunting galaxies, due to the near Milky Way. Nevertheless, it is interesting to see, what's all in the constellation, and to look at deep sky objects through dense star fields.

A less crowded area off the Milky Way is the constellation Leo Minor, with 232 square degrees not too extented, but with a considerable large number of galaxies. Burham's Celestial Handbook [2] lists not more than 20 galaxies, the Uranometria contains 69 galaxies, and a first compilation by members of the Fachgruppe Deep Sky of the german Vereingung der Sternfreunde lists more than 300 objects. So, inspired by the celebrated Hubble Deep Field the idea of a "complete" survey arises. But what is ment by "complete"? First, one could accumulate all known galaxy catalogues, extracting the Leo Minor objects. The result is a mix, which cannot really be presented with good conscience. The main problems are the cross-identifications - it's possible to produce a "cluster of identical galaxies" - and the large gaps in the data.

Fortunately, my own deep sky database called CAT2000 [13], covering the sky north of -30°, is reliable enough to be a good starting point. Moreover the NGC/IC fraction has no lack of data and gives accurate coordinates north of -15°. This is the result of a task called "Revised New General and Index Catalogue" [13] as part of the international "NGC/IC Project", headed by Harold Corwin jr.

Next, every non-NGC/IC galaxy was checked with the Real Sky software (critical cases with DSS). Accurate coordinates were measured and missing data added. By the way 153 new objects in the inspected fields were catalogued. So the resulting database is a complete set of known objects , but surely not a complete set of galaxies in Leo Minor. For this, exact statistical limitations must be given (e.g. magnitude limit) and the area of Leo Minor should be surveyed completely. This is let to future work.

Anyway, looking at the result, I could not resist calling it the "Amateur Deep Field". Enjoy! And, as Harold Corwin put it: "Only 87 constellations to go!".


2. Content and structure of the catalogue

The catalogue contains 1379 galaxies. The meaning of the catalogue fields is listed in Tab. 1. The individual fields are discussed in detail in the following sections.

Tab. 1 - Explanation of the catalogue fields

Field Explanation
Rect, Decl Right ascension, declination (equinox 2000.0)
Mag Photographic magnitude
a, b Larger/smaller diameter (')
PA Position angle (°)
Type Type (Hubble, PGC format or other)
ID1, ID2, ID3 Main identification and cross identifications
Remarks Additional information

2.1 Coordinates

The coordinates are given for the equinox 2000.0. All coordinates were determined from RealSky [12] and checked, whenever possible, with the Lick Northern Proper Motion Survey Galaxy Calalogue (NPM1G) [8] and a new list of accurate MCG positions (Corwin et. al. [3]). The comparison shows, that the measured coordinates have an accuracy of 1-2". Taking over coordinates from the PGC is not advisable, because these can be very poor (MCG- or Zwicky-data were often precessed without verification).

2.2 Magnitude, sizes, position angle and type

The magnitudes listed in the field Mag are photographic, based on plate inspections/measure-ments (ZWG, MCG, DSS and RealSky). One new source is the NPM1G [8] which gives precise positions and magnitudes. In some cases the magnitudes between PGC, UGC and NPM1G differ by more than 2m (the difference between PGC and NPM1G is 1m; in most cases the PGC lists the brighter magnitude). For a galaxy with compact core and diffuse halo the difference to the NPM1G is comprehensible (due to the digital plate measuring process; H. Corwin, private communication).

In the literature the data for sizes and position angles (fields a, b and PA) are very incomplete (except data from UGC and FGC). New data given here come from visual inspection of the DSS and RealSky. There are no gaps remaining. In some cases of double systems (e.g. type E+E) sizes and PA refer to the entire system.

There is a curiosity concerning the PAs in the PGC for MCG galaxies which are not in the UGC: some PA's must be mirrored at 90° (e.g. 20° must be 160°), which was also found by Karachentsev [7].

The field Type gives the Hubble type (mainly from UGC) or the slightly different PGC notation (C=compact, D=dwarf, E=elliptical, I=irregular, L=lenticular (S0), P=peculiar, S=spiral, B=bar, R=ring , M=mixed). AGN stands for "active galactic nucleus" - these objects come from Veron's "Catalogue of Quasars and Active Galactic Nuclei" [15].

2.3 Identifications and remarks

The fields ID1, ID2, ID3 contain the main identification and cross identifications (Tab. 2 explains abbreviations and names). If space is not sufficient a second line is introduced and/or the field Remarks contains additional identifications (e.g. NGC 3104 = PGC 29186 = UGC 5414 = MCG 7-21-7 = ZWG 211.6 = ARP 264 = VV 119). The most important references are given in chapter 3, additional ones can be found in the Master List [5] or the RC3 [4]; the nomenclature is also explained in [6].


Tab. 2 - Abbreviations of the catalogues used in the identification and remarks fields (N counts the number of cases).

ID Explanation N
ARAK Arakelian (galaxy) 9
ARP Atlas of Peculiar Galaxies [1] 7
3C Third Cambridge Catalogue of Radio Sources 4
CBS Case Blue Star 1
CG Case Galaxy 2
CSO Case (blue) Stellar Object 1
DDO David Dunlop Observatory (dwarf galaxy) 4
1E, 2E Einstein satellite data 2
FGC Flat Galaxy Catalogue (the extension ist FGCE; the addendum is refered by a following 'A') [7] 52
HARO Galaxy with UV excess 4
IC Index Catalogue 46
KARA Karachentseva (isolated galaxy) 10
MCG Morphological Catalogue of Galaxies [17]; first number = declination zone (+15 to -6, "+" sign is omitted), second number = field in zone (by right ascension), third number = galaxy in field. 376
MK Markarian (galaxy with UV continuum) 14
MS Einstein Observatory Extended Medium-Sensitivity Survey 4
NGC New General Catalogue 63
NPM1G Lick Northern Proper Motion Survey Galaxy Catalogue [8]; Format: declination zone (°) + number 576
PG Palomar Green 1
PGC Catalog of Principal Galaxies [11] 755
RX AGN from ROSAT all-sky survey 1
TON Tonanzintla 1
UGC Uppsala General Catalogue of Galaxies [9] 171
UGCA Catalogue of Selected Non-UGC Galaxies [10] 2
VV Vorontsov-Velyaminov (interacting galaxy) [16] 11
ZW Catalogue of Selected Compact Galaxies and of Post-Eruptive Galaxies [18], based on 7 lists 1
ZWG Zwicky's Catalogue of Galaxies and of Clusters of Galaxies [19]; the desgination CGCG is also in use (with '-' instead of our '.'); Format: first number = field, second number = galaxy in field 397
Sum   2517

3. Literature

[1] Arp, H. C., Atlas of Peculiar Galaxies, Pasadena 1966 (see also: Astrophys. J. Suppl. 14, 1 (1966)) [ARP]

[2] Burnham, R. W., Burnhams Celestial Handbook, Vol 2, New York 1978

[3] Corwin, H. G., et al., Accurate Positions for MCG Galaxies, 1997 (paper submitted to PASP)

[4] de Vaucouleurs, G., et al., Third Reference Catalogue of Bright Galaxies, New York 1991 [RC3]

[5] Dixon, R. S., Sonneborn, G., A Master List of Nonstellar Optical Astronomical Objects, Ohio State University Press 1980 [MOL]

[6] Fernandez, A., Lortet, M.-C., Spite, F., Astron. Astrophys. Suppl. 52, 1 (1983)

[7] Karachentsev I. D. et al., Astron. Nachr. 314, 97 (1993) [FGC]

[8] Klemola A. R., Hanson R. B., Jones B. F., Astron. J. 94, 501 (1987) [NPM1G]

[9] Nilson, P., Uppsala General Catalogue of Galaxies, Uppsala 1973 [UGC]

[10] Nilson, P., Catalogue of Selected Non-UGC Galaxies, Uppsala 1974 [UGCA]

[11] Paturel, G., et al., Monographies de la Base de Données Extragalactiques, No. 1, Vol. I-III, 1989 (see also: Astron. Astrophys. Suppl. 80, 299 (1989)) [PGC]

[12] RealSky, Astronomical Society of the Pacific, San Francisco, 1996

[13] Steinicke, W., CAT 2000 Astro-Database and Presentation Software, Umkirch 1996

[14] Steinicke, W., Revised New General Catalogue and Index Catalogue, Umkirch 1997

[15] Veron-Cetty, M. P., Veron P., Quasars and Active Galactic Nuclei (7th Ed.), ESO Scientific Report, 1997

[16] Vorontsov-Velyaminov, B. A., Atlas and Catalogue of Interacting Galaxies, Part I, Moscow 1959 (for Part II see: Astron. Astrophys. Suppl. 28, 1 (1977)) [VV]

[17] Vorontsov-Velyaminov, B. A., Arkhipova, V. P., Morphological Catalogue of Galaxies, Vol. I-IV, Moskow 1962-1968; (see also: Kogoshvili, N. G., Merged Catalogue of Galaxies, Bul. Abastumani Astr. Obs. 46, 133 (1975)) [MCG]

[18] Zwicky, F., Zwicky, M. A., Catalogue of Selected Compact Galaxies and of Post-Eruptive Galaxies, Zürich 1971 [ZW]

[19] Zwicky, F., et al., Catalogue of Galaxies and of Clusters of Galaxies, Vol. 1-6, Pasadena 1963-68 [ZWG]