Costa Rica - The Southern Globulars

20" f/5 (7/8/02 - Magellan Observatory, Australia): this was the best view I had of 47 Tucana during the week. At 212x, the entire 23' field was packed edge-to-edge with pinpoint stars and the blazing core, which had a yellowish tint, was resolved into a mesmerizing dense mat of stars. The halo extended to at least 30'.

18" (7/6/02 - Magellan Observatory, Australia): at 171x, this breathtaking globular was viewed at over 50° elevation and was stunningly resolved into several thousand stars out to a diameter of over 25'. The star density steadily increases towards the center. The roughly 4' core was blazing and highly resolved right to the edge of a very small compressed nucleus. A 3-dimensional affect was very strong with layers of stars forming a dense mat over the core. Many of the stars in the halo are connected in chains and lanes. The 9 Nagler does a better job of busting apart the stars in the core, although the cluster overfills the field at this power. The total visual magnitude is just slightly fainter than Omega Centauri and the size slightly smaller, but certainly equal in visual impact.

12" (6/29/02 - Bargo, Australia): While at Bargo, I observed 47 Tucana still very low in the sky but an easy 4th magnitude naked-eye blur just west of the SMC. At 186x, it filled the 26' field with an uncountable number of stars. Strongly concentrated to an intense, blazing core which was only partially resolved at a low elevation. The highly resolved outer halo extends ~25' in an irregular outline while the central halo was very symmetric.

18" (7/6/02): this bright globular is situated just north of the SMC (it's much closer at ~20,000 ly) but unfortunately is overshadowed by 47 Tucana on the west side of the SMC. At 228x, it appeared very bright and well-resolved into a couple of hundred stars! The rich halo is plastered with stars and extends to nearly 8'. The 2' compressed core is well-concentrated to a blazing center. Stars appear to stream out of the core in spiral curving lanes. This globular has a classic symmetric appearance with a prominent, round core and halo.

18" (7/8/02): bright, symmetric globular, ~5' diameter, with a large very bright condensed core (concentration class II). A mag 9 star lies 3.6' NE of the center, outside the halo. At 171x, the halo is just resolved into a large number of faint stars.

20" (7/8/02): at 212x, the resolution was a bit better in the halo than with the 18" NGT, but the blazing core was still unresolved.

13.1" (2/20/04 - Costa Rica): at 200x, this compact globular is very bright, strongly concentrated with an intense 1.5' core and a 4-5' fainter halo. The core is very lively and there are ~30 stars resolved, mostly in the loose halo, including a neat string of stars running SSW-NNE along the W edge of the core.

13.1" (2/19/04 - Costa Rica): excellent view at 200x. Contains an intense, 1' core which is mottled and partially resolved, particularly around the edges. The halo is easily resolved with several dozen brighter members peppered in the halo and around the periphery (~40 stars counted) although there are no dense knots. Surrounding the inner core (nucleus) is a dense ring of high surface brightness which is very mottled and in good moments of seeing breaks up into a swarm of stars. Located 40' ENE of 5th magnitude h3752, which is a striking mag 5.5/6.7 pair at 3".

13.1" (2/20/04 - Costa Rica): at 200x, this is a compact, fairly bright globular. Well-concentrated with a bright 1.5' core and a fainter halo of ~3' diameter. Roughly two dozen stars are resolved including several across the core and a number of stragglers which are easier to resolve in the outer halo.

13.1" (2/20/04 - Costa Rica): this very bright globular is large and elongated, ~8'x6' SW-NE increasing to 2' bright core and a blazing 40" nucleus. At 144x, this cluster is mottled but with no obvious resolution. At 166x a large number of extremely faint stars (mag 14-15) pop in and out of view over the entire disc, though cannot hold the resolved stars steadily.

18" (7/8/02 - Australia): at 171x, this bright globular (ranked 10th brightest at V = 6.1) is fairly large, ~10' diameter and very compressed with a blazing 2' core. The halo is noticeably elongated, nearly 3:2. A dense swarm of mag 14 and fainter stars are resolved in the halo and around the edges of the core but the inner central core is unresolved. At 228x, there appear to be some very faint stars lanes streaming into the halo which are just unresolved but look like small tentacles. A mag 10/10.6 double at 16" is outside the cluster ~10' ESE. This is by far the brightest concentration class I globular and the only one easily resolved. Visible naked-eye.

18" (7/8/02): beautifully resolved globular at 171x and 228x. The cluster is fairly large, ~8'-10' diameter with more careful viewing. Roughly 150 stars are resolved, though the number grows with magnification and averted visionA fairly dense layer of brighter mag 11.5-12 stars are resolved right over the bright core. The halo, which has a large number of mag 13 stars, has a scraggly, irregular edge and seems elongated - possibly partially obscured by dust. This concentration class X cluster is 7th in ranking of brightest stars and 10th in horizontal-branch mag stars (high resolution).

18" (7/7/02): at 228x, this large, loose globular (concentration class XII) is well-resolved into ~100 stars mag 12-15 with a 12' diameter. The roundish core is ~4' in size with many faint stars sprinkled across the core. The halo is elongated and irregular in shape. A starless dark lane appears to wind into the cluster towards the core from the NW side angling roughly NW-SE (verified on DSS). A mag 6.8 star lies 5' NW of the core and interferes with viewing! Located 44' SW of mag 3.8 Gamma Muscae.

18" (7/10/02): This was a surprising find for a little-publicized globular! At 171x, it appeared as a bright, fairly large globular of low concentration class. The loose halo was highly resolved and numerous stars were splashed across the brighter core. Many of the stars formed large loops and chains. A single bright star (mag 8.7 SAO 256996) is superimposed on the northern side of the halo. The core spans roughly 3', while outliers increase the overall halo to at least 10' [John Herschel gave similar dimensions]. Located 42' NNW of mag 3.6 Delta Muscae.

13.1" (2/20/04 - Costa Rica): at 105x in excellent seeing, the view was absolutely breathtaking with wall-to-wall pinpoint stars in the 37' field! There was a clear 3-dimensional effect with the 11.5-12.5 magnitude stars seemingly floating over a dense mat of fainter stars with the streamers in the halo reaching the edges of the field. I don't recall a more impressive view in the 12" from Australia, where the cluster was higher in the sky.

13.1" (2/19/04 - Costa Rica): In very good seeing seeing early in the morning of the 20th, Omega Cen was a mesmerizing sea of a couple of thousand stars at 200x. I set Omega just outside the field and let it drift through the field a few times. The outer halo was an amazingly dense swarm of 12-13th magnitude stars over a background of fainter pinpoints of lights overspilling the field. Very broadly concentrated to a large, brighter center which is denser although there is no well-defined core.

12" (6/29/02 - Bargo, Australia): this was the first object I viewed at Bargo with Les Dalrymple's 12" and was not disappointed. At 140x, it filled 2/3 of the field (over 25') and resolved into a few thousand stars down to the center. The cluster seemed almost 3-dimensional with a lattice of brighter mag 12 stars superimposed on a dense background layer of mag 13-14 stars. The density was generally uniformly high in the elongated halo except near the edge although the core shows more non-uniformity with a couple of darker patches.

20" f/5 (7/08/02 - Magellan Observatory, Australia): at 208x with a 24' field, the cluster overfilled the field with edge to edge stars mag 11.5 and fainter and was a breathtaking sight. Broadly concentrated with large, brighter core of at least 10' in diameter which is extremely densely packed with layers of stars. The elongated halo gradually thins but has no definite border out to 30'! This is the largest and brightest globular in the sky (V = 3.7) and an obvious naked-eye blur, but lacks the strong central condensation of NGC 104 = 47 Tucana.

13.1" (2/20/04 - Costa Rica): at 105x this globular appeared very bright, moderately large and well-condensed with an intense, mottled core. At 200x, 15-25 14th magnitude stars pop in an out of view (some in chains), though only a handful are easily visible including a brighter star just east of the core. Located 4' NW of yellow mag 4.7 M Centauri in the same high power field! The fairly bright planetary N5307 lies 44' ENE. Easy in 9x50 finder, though small.

C-8 (7/13/91 - Southern Baja): moderately bright, fairly small, 2.5' diameter, round, evenly concentrated to a bright central region and a small bright core, mottled halo, one brighter mag 12 star on the SE side. On the verge of resolution although viewed at only 8° elevation. Mag 4.7 M Centauri with mag 11 companion 40" separation just 4.1' SE of core!