Globular cluster in WLM?

[akarsh]

Hi

Has anyone observed the globular cluster in WLM?

After finding WLM brighter than expected, I tried it a few hours ago, with some success. It flashed in and out a few times. At ~300x was where I had the best observation, where I seemed to be able to hold the object continuously for some short amount of time. However, I am not 100% certain of the observation due to the faint stars in the vicinity. Rocking the focus really helped.

Update: I was looking at the wrong object. This is a report on the faint galaxy near WLM, not an observation of WLM 1.

Clear Skies!
Akarsh

[glxytrios]

Hi Akarsh, I observed the WLM system in October last year from a site at 8,500 ft in the White Mountains, CA. WLM was easy as a large, fairly faint N-S elongate patch with some eF stars superimposed. I observed WLM 1 (the globular cluster) just south of a mag 14.5 star at 244X. My notes say "extremely faint, slightly fuzzy observed with averted vision". In August this year at the Oregon Star Party, I observed Hodge 5 in NGC 185 at 527X ("very occasionally with averted vision"). For both observations I used my Starmaster 20" F3.3.

Clear skies, Miles (glxytrios)

[akarsh]

Miles, thank you for sharing your observations. I haven't even thought of seeing a globular cluster in NGC 185! That might be worth going after. Thank you again.

Clear Skies
Akarsh

[akarsh]

Oh wow, it turns out I was looking for the wrong object . I mistook the faint galaxy near WLM for the globular cluster, so the report was an attempted observation at that. Must go after the globular cluster tonight...

[Steve Gottlieb]

Hi Akarsh, I observed the WLM system in October last year from a site at 8,500 ft in the White Mountains, CA. WLM was easy as a large, fairly faint N-S elongate patch with some eF stars superimposed. I observed WLM 1 (the globular cluster) just south of a mag 14.5 star at 244X. My notes say "extremely faint, slightly fuzzy observed with averted vision". In August this year at the Oregon Star Party, I observed Hodge 5 in NGC 185 at 527X ("very occasionally with averted vision"). For both observations I used my Starmaster 20" F3.3.

Clear skies, Miles (glxytrios)

I had pretty similar results as Miles with Hodge V in NGC 185 with my 24-inch f/3.7, though at a lower-elevation site (1000 ft). Here's what I logged, "At 325x and 450x Hodge V appeared as an extremely faint star [V = 16.7], forming the southern vertex of a small equilateral triangle with a mag 14.5 star 20" N and a mag 15 star 20" NW. It was repeatedly glimpsed for brief moments and a couple of times was held continuously for a few seconds. Situated 3.8' NE of the center of NGC 185 and outside the visible halo of the galaxy.

Steve

[wvreeven]

According to Simbad, there is another globular cluster in NGC 185 (FJJ NGC 185 III = Hodge III) brighter than V = 17.0. Has anyone ever tried to see that one?


Wouter

[akarsh]

Thanks for sharing your report Steve.

I got around to correctly observing WLM 1 last night. My logs say:

"Sensed on and off, ~50% holding, best at 10mm Delos (205x). Had good glimpses in 4.5mm Delos (457x) at moments of good seeing."

The object was round, tiny, and distinctly diffuse.

Clear Skies!
Regards
Akarsh

[Uwe Glahn]

Hi Akarsh,

with 16" a difficult object but manageable under very good transparency. With 257x it keeps still stellar. With better seeing perhaps diffuse?

16", 100x-257x, Seeing II-III, NELM 7m+
WLM.jpg

labeled version
WLM_be.jpg

[Howard B]

Here's my observation from 2008:

"This is a big and faint galaxy...that stands out best overall at 105x, but is more interesting at 253x because of the faint field stars that became visible..." 28 inch, 21.95 SQM (7400 feet altitude)

WLMgalaxy.jpg WLMgalaxy_invert.jpg

Although I wasn't trying to see the globular, I did mark a faint stellar point at the correct location - which is too bad. I would have enjoyed the observation even more had I known what I was seeing at the time. Regardless, this was one of the darkest and most transparent night ever, and the seeing was pretty good too!

[Steve Gottlieb]

According to Simbad, there is another globular cluster in NGC 185 (FJJ NGC 185 III = Hodge III) brighter than V = 17.0. Has anyone ever tried to see that one?

Wouter

Paul Hodge's 1974 paper "Photometry of the Globulars in NGC 185" identifies this second globular as Hodge 4, so I'll use that designation. Despite being marginally fainter than Hodge 5 (V = 16.8 vs. 16.7), I missed Hodge 4 in the same observation. Hodge 5 is well outside the halo while Hodge 4 is in or at the edge of the halo, which may make it a bit tougher. That's my excuse, anyways -- though I plan to try again in better conditions.

[wvreeven]

Thanks for the reference to Hodge's paper, Steve. I assumed the numbering scheme would be the same. Looks like Hodge 4 is a challenging object but I'll give it a try as well.


Wouter

[wvreeven]

I had a go at both WLM and NGC 185 last night with my 20" from 21.2-21.4 skies.

WLM: visible at 83x as a fairly large, faint ellipse without a distinct core. On one side along the short axis lies a faint star just outside of the galaxy. At 151x two brighter patches become visible inside the galaxy. One more or less between the core and the faint star, one further south in the galaxy. The one near the core is easier to see than the one further south. At 320x I see the globular cluster pop in and out of sight.

NGC 185: at 83x I see a very large ellipse with a stellar core. This galaxy is much easier to see than nearby NGC 147 (which also has a stellar core). At 545x and 692x I occasionally see Hodge 5 pop into view about 25% of the time. Along the long axis just outside of the galaxy in the direction of Hodge 5 I saw a faint star. Along the short axis just at the edge of the galaxy on the side of Hodge 5 I see a fuzzy "star". That's Hodge 3. A bit further outside on the same side lies but slightly away from Hodge 5 lies another faint star. I found Hodge 3 easier than Hodge 5. Hodge 5 appeared to me distinctly stellar while Hodge 3 appeared fuzzy. In general I find faint fuzzies easier to see than faint stars.

[akarsh]

Hi Akarsh,

with 16" a difficult object but manageable under very good transparency. With 257x it keeps still stellar. With better seeing perhaps diffuse?

Uwe, I wish I had taken better notes, but I recall that the distinct diffuseness was at 457x. If I recall correctly, it looked like an star only visible with averted vision at 205x.

Clear Skies
Akarsh

[akarsh]

labeled version
WLM_be.jpg

Hallo Uwe,

Could you actually see the HII regions you have marked in WLM? If so, I'd be grateful if you could share your observing report. Seems like a very challenging and interesting observation!

Also, are these observations from Austria? Or are they from a more southern location?

Regards
Akarsh

[akarsh]

Dear DSF,

Thanks to the inspiring reports, I decided to give a go at Hodge V of NGC 185. This was a very tough challenge for an 18", especially under the seeing conditions I had. The detection at 450x power was marginal, with the object flashing in about 6 ~ 7 times. I could hardly ever hold the object for any length of time, except maybe on two occasions, where I managed to hold it for about a second. These were moments of what might have been good seeing. The globular itself is at the apex of an equilateral triangle, whose base made of two stars that I could hold about 90% of the time. Further away from the base along the bisector of the equilateral triangle is a star of similar faintness to the globular (as seen from the DSS), and this star was only marginally better in visibility.

I had expected to see more of this object with an 18", but I guess that's what it is. Maybe a night of better seeing could help?

Regards
Akarsh

[Uwe Glahn]

Arkash,

Could you actually see the HII regions you have marked in WLM? If so, I'd be grateful if you could share your observing report. Seems like a very challenging and interesting observation!

Of course yes - the in the sketch marked HII objects were seen. WLM 8/9 was easy to see, I could hold the stellar plob with averted vision. To WLM 6 I noted pretty tough and at the visual limit that night.

Also, are these observations from Austria? Or are they from a more southern location?

The observation and sketch were made from Austria from the Alps at a very transparent night.

[akarsh]

Hi all,

I was digging through the same old notes from Okie-Tex star party in 2015, and I don't know why I concluded that the object I saw was not WLM 1. I am guessing that Uwe's sketch is oriented north up, whereas Howard's sketch is oriented with the north at about 190° (clockwise). In this case, my sketch, which matches the DSS at an orientation of about 150° (clockwise) does seem to mark WLM 1 fairly clearly. The arrow that I had pointing to it does look ambiguous, as though there could be an object superimposed with the arrowhead, which would have been incorrect, but I "deconstructed" the arrow in the software I used to take my notes and it does not appear like there was a marking right under the tip of the arrow. So it does appear that I indeed had a correct observation... Let me know what y'all think. In any case, it tells me I should try go after WLM 1 again. I'm amazed Uwe saw it from Austria, which motivates me to try from California.

Screenshot_20200925_220233.png

(10mm => 205x, 4.5mm => 468x on my scope)

I see some potential source of confusion. The following website on Adventures in Deep Space shows WLM-1 as indeed appearing as a double star.
https://www.astronomy-mall.com/Adven...ce/gcextra.htm

Wikipedia (as of now) incorrectly states that the globular in WLM is PGC 910901, which is quite likely wrong because this object appears like a background galaxy.

SIMBAD agrees with Adventures in Deep Space here --> http://simbad.u-strasbg.fr/simbad/si...OBULAR+CLUSTER

[akarsh]

After much confusion caused by poor logging and confusing orientation of the maps, I've finally reconfirmed having observed WLM-1. Quoting from my observing report from October:

"
6. WLM globular cluster
This was very tough. Best views @ 200x, 290x. Stellar, yet fuzzy patch that only pops occasionally. <~ 10% holding.
"