(1/30/06): A few objects from Costa Rica

by Steve Gottlieb


On the first evening we had a few hours of observing and I picked up several bright winter objects in Carina, Vela, Puppis and Canis Major and one dim object (IC 2220) before clouds shut things down pretty much for the rest of the week (whenever possible I chased down far southern double stars). The real highlight, of course, was a relaxing week on a beautiful Costa Rica ranch with an amazing array of tropical birds, iguanas, monkeys, crocodiles, armadillos and other animals I couldn't identify.

NGC 2516 = Running Man Cluster 07 58.0 -60 45 V = 3.8; Size 30
13.1" (1/30/06 - Costa Rica): very bright naked-eye cluster located 3° SW of Epsilon Car (western star in the False Cross). Appears partially resolved in the 9x50 finder and excellent using the 15x50 IS binoculars. Fills over half of the 20 Nagler field, ~35' diameter with over 100 stars resolved. The outline is quite irregular though well-detached at low power. A mag 5.5 orange star (HD 66342) lies to the NE of the cluster. The central region is more concentrated and uniform. Includes a number of tinted yellow or orange stars. A nice triple (h4027 = 8.4/8.8/9.9 at 9" and 29") is on the west side and an excellent double (h4031 = 7.2/8.0 at 5") lies on the east side of the cluster. A long curving string starts in the center and heads to the mag 5.5 orange star to the NE. This string includes a 9" evenly matched pair (I 1104) of mag 9 stars (resolved at low power).
IC 2220 = Toby Jug Nebula 07 56 50.9 -59 07 32 Size 6.0:x4.0:
13.1" (1/30/06 - Costa Rica): at 105x the "Toby Jug Nebula" is visible surrounding a bright red variable star, V341 Carinae and was easy to chase down just 1.6' N of naked-eye N2516. The nebula appears as a large, irregular glow unfiltered. With careful viewing the west side is bowed in with thin extensions to the west on the north and south ends. The nebulosity is not as extensive on the following side of the star.
NGC 2362 07 18 42 -24 57.3 V = 4.1; Size 8
13.1" (1/30/06 - Costa Rica): gorgeous low power field surrounding Tau CMa using the 20 Nagler (75x). Tau was easily resolved into a triple with two mag 10 and 11.2 companions at 8" and 14" to the east. At 170x, 75-80 stars are visible and the cluster appears fully resolved. A string of stars passes to the north of Tau oriented NW to SE. Several faint stars and a detached clump lies to the north of Tau beyond the string. A mag 8.5 star marks the south border of the cluster.
NGC 2467 07 52 29 -26 25.8 Size 8x7
13.1" (1/30/06 - Costa Rica): bright, large nebulosity at 75x using an OIII filter, ~4-5' diameter, surrounding a mag 7.5 star. The main section is roughly mushroom shaped, extending generally south of the bright star. The southern border is locally brighter along a strip oriented NW to SE. There is a sharp light cut-off (apparently due to dust) passing to the north of the central star and oriented E-W. Faint haze extends 15' to 20' to the east towards a 12'-15' string of brighter stars that are oriented NW to SE. The nebulosity brightens and broadens into a 12' stream roughly parallel to the group of brighter stars (catalogued as Haffner 18). Removing the filter this a gorgeous low power milky way field with numerous faint stars superimposed in the region of the nebula.
NGC 2546 08 12 16 -37 35.7 V = 6.3; Size 41
13.1" (1/30/06 - Costa Rica): this very large, bright scattered cluster was just visible to the naked eye close south of a brighter, hazy naked-eye patch of unresolved stars. The field is beautifully rich, at least 45' diameter though there was no distinct borders. The star field looks impressive beyond the edges of the 66' field of the 20 Nagler. On the NW side is a rich, elongated strip of ~20 stars that is quite eye-catching. Includes a few pairs and a neat triple including a fairly close unequal mag pair at the SSW end of the elongated strip.
NGC 2547 08 10 11 -49 13.5 V = 4.7; Size 20
13.1" (1/30/06 - Costa Rica): this naked-eye cluster to the south of Gamma Vela is roughly 30'x20' in size. There is a very distinctive, gently curving arc of stars bowed out to the east that defines the eastern side of the central region and the brightest mag 6.5 star is along this arc. Three nice pairs are to the W and NW of the mag 6.5 star (one of these pairs has a third fainter companion forming a triple). The main portion of the cluster is enclosed in two outer strings of stars that form a large "V" with the vertex to the east of the mag 6.5 star and these pair of strings increase the diameter to 30'. While scanning for NGC 2547 I ran across a bright, distinctive red star to the west (probably M3 class HD 67821)
IC 2391 = Omicron Velorum Cluster 08 40.3 -52 55 V = 2.5; Size 50
13.1" (1/30/06 - Costa Rica): very bright and large naked-eye cluster surrounding mag 3.6 Omicron Vel (just north of the False Cross). Resolved in 9x50 finder ro 15x50 IS binoculars. Includes 7 bright stars including a wide (1.3'), bright pair of mag 5 stars on the east side. The border of this scattered group is not well defined but the fainter stars fill out over a degree in the 20 Nagler 66' field.


Posted on sf-bay-tac Feb 09, 2006 15:56:16 PT
Converted by report.pm 1.2 Mar 05, 2006 21:01:45 PT