WLM Galaxy

Published comments

Melotte, P.J. (1926)

New nebulae shown on Franklin-Adams Chart plates. MNRAS, 86(8), 636-638.

Discovery paper.

de Vaucouleurs, G. (1975)

de Vaucouleurs, G. (1975) Nearby groups of galaxies. In: Kuiper, G. (ed) Stars and Stellar Systems. Volume 9: Galaxies and the Universe. Chapter 14, p557.

p 589: Listed in Table 9: "DDO dwarfs > 8 arcmin"

DDO 209 = WLM, apparent diameter = 11.0 arcmin.

Schmidt (1993)

Other names: "WLM,UA444". Inclination: (face-on, in degrees) 65 Total photoelectric blue mag 11.03 Logarithm of the angular diameter D25 (arcminutes) 2.06 This galaxy is included in a sample of galaxies with velocity less than 500km/s with respect to the centroid of the Local Group. [Nearby Galaxies. Schmidt K.-H., Priebe A., Boller T. (Astron. Nachr. 314, 371 (1993))]

Photo index

Photo index by Jim Lucyk: Rev.Shapley-Ames Cat.of Bright Gal. (Sandage,Tammann 1981) p113

Modern observations

[amastro] WLM observations

It would be interesting for folks observing the WLM galaxy to use the photometric sequence by Sandage & Carlson to see how faint they're going, and also to help judge the brightness of the globular cluster on its west side. The list of isolated sequence stars is given below in order of magnitude, which is extracted from my large photometric reference file:

ftp://ftp.lowell.edu/pub/bas/starcats/loneos.phot.gz

The paper about the galaxy and the chart showing these stars is available via the ADS Web site. Use this very long single-line URL to view the chart:

http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1985AJ.....90.1464S&page=112&plate_select=YES&data_type=GIF&type=SCREEN_GIF&nosetcookie=1

The globular cluster is object D on the chart, which S&C give as V=16.1 and B-V=0.6. The star that Derek mentions near the globular is star C at V=14.5, much brighter than the GSC value. This is because for most of the sky south of about +3 Dec, the GSC magnitudes are derived from blue plates (note that star C has B=15.4, not far from the GSC value).

It might make the Germano photo at Jim Shield's site more useful if the sequence could be labelled there, too. Finally, note that the position given for the globular is in error, and should be: 0 01 49.5 -15 27 31 (2000, from USNO-A2.0).

\Brian

Name RA (2000) Dec s GSC V B-V

WLM AA 0 01 33.4 -15 22 33 A 5838-0142 12.49 0.56

WLM I 0 01 48.9 -15 20 11 A 5838-0416 12.75 0.57

WLM C 0 01 49.2 -15 26 54 A 5838-0798 14.53 0.83

WLM V 0 02 12.9 -15 26 49 A 14.91 0.69

WLM B 0 01 45.7 -15 22 30 A 5838-0217 14.93 0.42

WLM A 0 01 45.3 -15 23 34 A 15.81 0.88

WLM G 0 02 10.9 -15 29 16 A 17.67 0.84

WLM F 0 02 08.3 -15 29 13 A 18.39 0.52

WLM K 0 01 52.0 -15 19 55 A 18.39 0.67

WLM L 0 02 06.4 -15 20 47 A 18.63 0.84

source:

1985AJ.....90.1464S

SANDAGE A. and CARLSON G.

Astron. J., 90, 1464-1473 (1985)

The brightest stars in nearby galaxies. VI. Cepheids and the brightest stars

in WLM.

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Thanks, Brian. Looking at the image, I remember seeing stars A and B--neither was particularly difficult compared with the globular D. The bright triangle of "stars" within the galaxy were also much easier to see than the globular. I thought these were all superposed field stars, but examination of plate 113 of the paper Brian cited suggests that at least one (containing #72) may be a combination of bright supergiants within the galaxy.

By the way, I was at Joshua Tree, CA at an elevation of only a few hundred feet :-)

Derek

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Last night was first light for my tracking 18" Dob, and I decided to track down my first extragalactic globular cluster. After perusing some showpiece objects, I moved to the Wolf-Lundmark-Melotte (WLM) galaxy. There was some light pollution on the horizon, and limiting mag was approximately 6.0 at the level of the galaxy. At 100x (4.5 mm exit pupil), the galaxy was seen with difficulty as a very faint irregularly shaped elongated haze with at least three embedded stars.

The globular WLM-1 is listed in Richard Jakiel's article on Jim Shield's wonderful webpage http://www.angelfire.com/id/jsredshift/wlm.html

The image on the webpage shows the globular next to a 15.2 mag (GSC value) star of approximately equal brightness. However, the photo in the Observer's Guide under UA 444 which is also at Martin Germano's webpage

http://home.earthlink.net/~mcgermano/OldArchives/mcMCG-3-1-15.JPG

shows the globular as being dimmer than the star.

Visually, the star was fairly easy at high powers, but the globular was much more difficult. I had to use the much maligned Televue Zoom lens to optimize my magnification-seeing-eye curve. At 275x the globular was visible about 80% of the time using averted vision. I saw it as stellar, but another observer thought otherwise. In any case, at 314x the visibility dropped to 50% or less.

Jim's webpage has enough homework for awhile, but if anyone has other extragalactic globulars in galaxies other than M31+companions, M33 and Fornax (my next target) I'd love to hear about them.

Derek