Steve Gottlieb
July 31st, 2013, 08:03 PM
As there have been discussion and interest in observing the delights of the southern hemisphere, I thought I would post observing notes on my nine favorite, not-to-miss regions in the LMC. You'll find a variety of observations -- made with 13", 18", 24" and 30" scopes -- during 5 week-long observing trips to Australia and one to Costa Rica. For more on the LMC (and SMC), including charts, I'd suggest checking out these (http://www.asnsw.com/node/727) Astronomical Society of NSW articles.
If others have additional favorite deep sky objects in the LMC, please post!
1) Tarantula Nebula region
NGC 2070 = Tarantula Nebula (24"): at 200x unfiltered, I examined the 30 Doradus cluster = R136 cluster at the heart of the Tarantula Nebula. The cluster is dominated by R136a, a 10th magnitude bloated "star" at the center that would not focus sharply. Surrounding this star was a compact but very rich carpet of dozens of mag 14-15.5 stars packed into a 1' region that were much too numerous to count.
24": The Tarantula nebula was simply unreal at 200x in the 13mm Ethos with a UHC filter -- better than any photo I've seen and convincingly 3-dimensional, even though I viewed it late so the elevation was only 20°. Although this magnification brought out an unbelievable amount of detail in the loops and ribbons, the main complex fit snugly in the eyepiece field (30').
20": the Tarantula is the largest known emission region (800-1000 light years) and is easily visible to the naked-eye from Australia. The view of the Tarantula early in the morning through a 20" f/5 at 127x (20 Nagler) and OIII filter was jaw-dropping! Near the center are several bright loops and arcs. Extending out are a number of convoluted loops including one heart-shaped arch which is quite large. Running out from the central region of the nebula are streaming lanes of nebulosity. One in particular extends quite a long distance and the outer loops and streamers seem to merge into some of the nearby HII regions forming a mind-boggling complex. There are perhaps 10 different loops and ribbons in the main body giving a 3-dimensional effect. Near the center lies an extremely compact cluster of superluminous stars (R136) but only a few were visible including what appears to be a single bright star. Also a number of additional stars are scattered about the main body.
NGC 2042 (18"): fairly large patch of stars and haze (association LH 89), ~5' in size. At least two dozen stars are visible in an elongated group oriented SW-NE, including a few mag 10 stars over unresolved stars or haze. Two additional knots are to the NW and form an obtuse isosceles triangle with NGC 2042. The first knot is KMHK 1122 situated 5' NW, and S-L 585 at 10' NW. NGC 2042 is located just 17' NW of the center of the Tarantula Nebula.
NGC 2044 (18"): group of about a dozen stars in a 3' diameter at 171x dominated by three brighter stars in a 1' E-W string. Both the east and west "stars" in this line are actually compact clusters (eastern cluster = S-L 602) with multiple components on a HST image. Situated in the outer portion of the 30 Doradus complex 16' SW from the central core. Like NGC 2060, this stellar association (LH 90) also harbors a young SNR! The site of SNR 1987A (05 35 28, -69 16.2) lies only 5.5' SW.
NGC 2050 (18"): at 171x, appears as just a locally brighter spot containing perhaps a dozen stars over a hazy background glow (stellar association LH 93), ~2' in diameter. Embedded in the edge of an amazing 15'-20' linear stream of stars (association LH 93/94) which runs through the field from SW to NE which begins just off the south side of the tendrils of the Tarantula Nebula and heads southwest towards NGC 2050! Located 30' SW of the center of the Tarantula.
NGC 2060 (18"): this fairly small knot of nebulosity is situated just SW of the main mass of the Tarantula nebula approximately 7' from the center. About a half-dozen mag 12-14 stars are involved (association LH 99) with a total diameter of 2'.
Studies have shown this nebula contains a compact x-ray source and a rapidly rotating pulsar, indicating NGC 2060 is a Crab-like supernova remnant in the LMC! (see the 1998 IAU Circ., 6810, 2).
NGC 2069 (18"): this is the northern outer loop of the Tarantula Nebula which Dunlop and Herschel catalogued separately. Described as "almost, or entirely, detached from it." See observing notes for NGC 2070.
NGC 2092 (18"): very faint round knot, ~40" diameter with a brighter core. Located 4' W of NGC 2100 and 17' SE of the center of the Tarantula.
NGC 2100 (18"): this LMC cluster appears as a small, bright clump of stars and unresolved haze (V = 9.6) with a diameter of ~2'. Fairly compact and isolated with at least 10 mag 12 and fainter stars resolved. Located 20' SE of the core of the Tarantula nebula within the LMC O-association LH 111. On the DSS, this appears to be a very rich open cluster or globular.
KMHK 1122 (18"): small knot of stars picked up 5' NW of NGC 2042 (which is 17' NW of the center of the Tarantula).
S-L 585 (18"): small knot of stars of haze picked up 10' NW of NGC 2042 (which is 17' NW of the center of the Tarantula). A similar patch was ~6' WSW (KMHK 1122).
If others have additional favorite deep sky objects in the LMC, please post!
1) Tarantula Nebula region
NGC 2070 = Tarantula Nebula (24"): at 200x unfiltered, I examined the 30 Doradus cluster = R136 cluster at the heart of the Tarantula Nebula. The cluster is dominated by R136a, a 10th magnitude bloated "star" at the center that would not focus sharply. Surrounding this star was a compact but very rich carpet of dozens of mag 14-15.5 stars packed into a 1' region that were much too numerous to count.
24": The Tarantula nebula was simply unreal at 200x in the 13mm Ethos with a UHC filter -- better than any photo I've seen and convincingly 3-dimensional, even though I viewed it late so the elevation was only 20°. Although this magnification brought out an unbelievable amount of detail in the loops and ribbons, the main complex fit snugly in the eyepiece field (30').
20": the Tarantula is the largest known emission region (800-1000 light years) and is easily visible to the naked-eye from Australia. The view of the Tarantula early in the morning through a 20" f/5 at 127x (20 Nagler) and OIII filter was jaw-dropping! Near the center are several bright loops and arcs. Extending out are a number of convoluted loops including one heart-shaped arch which is quite large. Running out from the central region of the nebula are streaming lanes of nebulosity. One in particular extends quite a long distance and the outer loops and streamers seem to merge into some of the nearby HII regions forming a mind-boggling complex. There are perhaps 10 different loops and ribbons in the main body giving a 3-dimensional effect. Near the center lies an extremely compact cluster of superluminous stars (R136) but only a few were visible including what appears to be a single bright star. Also a number of additional stars are scattered about the main body.
NGC 2042 (18"): fairly large patch of stars and haze (association LH 89), ~5' in size. At least two dozen stars are visible in an elongated group oriented SW-NE, including a few mag 10 stars over unresolved stars or haze. Two additional knots are to the NW and form an obtuse isosceles triangle with NGC 2042. The first knot is KMHK 1122 situated 5' NW, and S-L 585 at 10' NW. NGC 2042 is located just 17' NW of the center of the Tarantula Nebula.
NGC 2044 (18"): group of about a dozen stars in a 3' diameter at 171x dominated by three brighter stars in a 1' E-W string. Both the east and west "stars" in this line are actually compact clusters (eastern cluster = S-L 602) with multiple components on a HST image. Situated in the outer portion of the 30 Doradus complex 16' SW from the central core. Like NGC 2060, this stellar association (LH 90) also harbors a young SNR! The site of SNR 1987A (05 35 28, -69 16.2) lies only 5.5' SW.
NGC 2050 (18"): at 171x, appears as just a locally brighter spot containing perhaps a dozen stars over a hazy background glow (stellar association LH 93), ~2' in diameter. Embedded in the edge of an amazing 15'-20' linear stream of stars (association LH 93/94) which runs through the field from SW to NE which begins just off the south side of the tendrils of the Tarantula Nebula and heads southwest towards NGC 2050! Located 30' SW of the center of the Tarantula.
NGC 2060 (18"): this fairly small knot of nebulosity is situated just SW of the main mass of the Tarantula nebula approximately 7' from the center. About a half-dozen mag 12-14 stars are involved (association LH 99) with a total diameter of 2'.
Studies have shown this nebula contains a compact x-ray source and a rapidly rotating pulsar, indicating NGC 2060 is a Crab-like supernova remnant in the LMC! (see the 1998 IAU Circ., 6810, 2).
NGC 2069 (18"): this is the northern outer loop of the Tarantula Nebula which Dunlop and Herschel catalogued separately. Described as "almost, or entirely, detached from it." See observing notes for NGC 2070.
NGC 2092 (18"): very faint round knot, ~40" diameter with a brighter core. Located 4' W of NGC 2100 and 17' SE of the center of the Tarantula.
NGC 2100 (18"): this LMC cluster appears as a small, bright clump of stars and unresolved haze (V = 9.6) with a diameter of ~2'. Fairly compact and isolated with at least 10 mag 12 and fainter stars resolved. Located 20' SE of the core of the Tarantula nebula within the LMC O-association LH 111. On the DSS, this appears to be a very rich open cluster or globular.
KMHK 1122 (18"): small knot of stars picked up 5' NW of NGC 2042 (which is 17' NW of the center of the Tarantula).
S-L 585 (18"): small knot of stars of haze picked up 10' NW of NGC 2042 (which is 17' NW of the center of the Tarantula). A similar patch was ~6' WSW (KMHK 1122).