Showpiece regions in the LMC (7)

[Steve Gottlieb]

7) LMC-N44 Complex

NGC 1929 (24"): this HII knot is the first in an impressive star cluster/emission complex (stellar association LH 47) that extends over 7' in size and includes NGC 1934, 1935, 1936, 1937, and IC 2126. At 260x it appeared as a bright, moderately large, round glow of ~50" diameter surrounding a 13th magnitude star.

On the DSS this object appears to be a symmetrical bubble. This HII complex and cluster includes the superbubble complex N44

NGC 1934 (24"): this is a locally brighter patch in the NGC 1929-34-35-36-37 complex (stellar association LH 47), situated very close northwest of NGC 1935. This patch is not as well defined as the other NGC objects in this bright HII complex but is noticeable as it involves a couple of brighter mag 12 stars and a number of fainter stars.

S-L 417 (24"): rich concentration of stars superimposed on the entire LMC-N44 complex, including the HII regions NGC 1929, 1934, 1935 and 1936 off the south side.

NGC 1935 (24"): this emission glow forms the NW pair with NGC 1936 in a very striking field of clusters and HII patches (part of stellar association LH 47). At 200x and UHC filter it appeared as a very bright, round glow of uniform high surface brightness. The size is slightly smaller than NGC 1936, perhaps 45"-50" in diameter. Good response to the UHC filter. Nebulosity also extends off to the NW of NGC 1935 and a locally brighter patch (NGC 1934) involves a couple of brighter stars. Superimposed on this entire complex of HII knots is a rich concentration of stars (S-L 417 = KMHK 822).

NGC 1936 (24"): NGC 1936 appeared as a very bright, round glow, ~1' diameter with a very high, uniform surface brightness at 200x using a UHC filter. Situated at the south end of a large cluster and HII complex. Additional fainter nebulosity sweeps to the south and is connected with a fainter (anonymous) patch to the west by 1'. This extension increases the total size to 2' to 2.5'. NGC 1935 lies 2' NW.

NGC 1937 (24"): this object is the furthest NE in a gorgeous field of stars and HII regions. NGC 1937 is a large nebulous patch, ~3.7'x2.7' in size, with ~20 stars resolved over the bright glow. Excellent contrast gain using a UHC filter at 200x. The cluster or star cloud (association LH 48) includes a string of stars oriented WSW-ENE that passes through the center including a mag 11 star. NGC 1936, a very bright nebulous glow, lies 5' S, and other sections of the N44 superbubble complex (see http://www.universetoday.com/am/publish/gemini_interstellar_cavern.html) lie to the SW including NGC 1929, 1935 and IC 2126. Superimposed on this complex of HII glows is a fairly rich concentration of stars.

IC 2128: Star cloud (Association LH 49) located at the SE end of the NGC 1929-1936 complex (LMC N44)

[Ivan Maly]

Another wonderful region. It seems pretty obvious that LH47 in its entirety was described by James Dunlop in the 1820s as #175 in his catalog. Here is the record from my observation of this area with 5.5", followed by some additional notes that I made after returning home:

SEDS says that Dunlop 175 is NGC 1936, one of the components of a very large complex N of the middle of the bar – just NE of the projected Milky Way cluster MGC 1901. Almost undoubtedly (check Dunlop’s notes) Dunlop 175 is the entire complex. (LMC is over the toilet.) The complex[‘s] shape [is] with the brighter arc on one side. All components glimpsed at high power (NGC 1929, 1934, 1935, 1936, 1937). -36 dominates and the 35-36 pair is definite. -37 is a well-separated haze. -29 is an unremarkable region.

[Dunlop’s note for his #175 reads: “A pretty large rather faint nebula, about 5’ diameter, irregular figure, partly resolvable into stars of mixt magnitudes. The nebulous matter has several seats of attraction, or rather it is a cluster of small nebulae with strong nebulosity common to all.” It seems to be beyond doubt that the Dunlop object is not NGC 1936 alone but the entire complex involved with it.]

[Marko]

Again Steve has done well and is picking real winners of areas (well done Steve).
This area is also on one of my minichart selections pages that I had used on my trip in 3/2010 as reminders of areas. I had extensive charts and so on but these were 'handy'. This is a different one that is more packed but has quite a few of the things Steve has been discussing as well as the Ngc1935 area here found in upper right 'mini-chart'.

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For an extensive set of southern sky charts you may visit my visual site here:
http://www.astrospotter.com/SouthernSkyAllCharts

[Ivan Maly]

Useful format of charts, Mark. And that place looks like a fine destination in Australia. Maybe next time...