U 433
16:30 to 17:30
-39° to -50°
Ara, Nor, TrA
May-Sep

FEATURED OBJECTS: ESO180-PN007, Cr 307, Lynga 12, IC 4642, NGC 6152, NGC 6208, NGC 6215, NGC 6221, NGC 6253, NGC 6326.

NGC 6152
Cr 304
RA 16:32:42
Dec -52°38.6'
Open cluster

h: "a large and coarse milky way cluster, tolerably insulted, composed of large stars."

10x50: "very dim, about 15' wide, 5 members were resolved" (suburban skies) [RH]

11x80: (urban skies): Irregular glow, looks like dense starfield only. About 1 degree north is a brighter, more coarse version. (exurban skies): This open cluster is not at all definite in 11x80 binoculars. It looks like a very slight brightening of the night sky, or a very faint part of the Milky Way. [AS]

6-inch f/8.6 Newtonian: At 52x, the 40' field appears as a patchy star field, too scattered to impress. Well bounded by stars. The larger 43x field is delicately sprinkled with small stars. Roughly in the middle of the cluster are two small knots of stars, clearly separated by a starless gap. The two knots lie oriented north-south. At 52x, the northern one appears triangular and the southern one, which is more prominent, appears elongated. At higher powers, the northern knot consists of four 10th mag stars in an irregular trapezium. The southern knot is triangular, and at its southern tip lies a double stars -- a total of 5 stars make up this triangle. Viewing at 144x doesn't show many more stars, and at this power you are looking right through the cluster, and the star-less voids are numerous. Stars seen to about 11th mag, and I guess there are overall 50 stars in the cluster, with 20 or so 9-10th mag stars. I estimate the Trumpler class as II 2 R-VR. On the western edge of the cluster is a fine, very unequal double star; the primary has a very distinct orange-red colour. (suburban skies) [AS]

Cr 307
ESO226-SC018
RA 16:35:19
Dec -50°59.5'
Open cluster

10x50: "nothing visible" (suburban skies) [RH]

Lynga 12
ESO226-SC022
RA 16:46:02
Dec -50°45.8'
Open cluster

NGC 6208
Cr 313
RA 16:49:30
Dec -53°43.7'
Open cluster

Dunlop 364 "A round, faint nebula, about 1' diameter, with three small stars in it; a bright star south of the nebula."

h: "A pretty insulated milky way cluster, class VII of large stars; 8' diameter; stars 9..12th magnitude." His second observation records it as "cluster class VII; rich; not much compressed in the middle; more than fills field; stars 11.14th mag but chiefly small."

Trumpler (Lick Obs Bul, Vol 14, No. 420) gives the diameter as 20' and the class as 4 2 mU.

Phil Harrington (1990, Touring the Universe through Binoculars) calls it an "attractive little open cluster found north of Zeta Areae. Here, observers will find a small 7th mag glow representing about 60 cluster stars. The brightest of these shine at 9th magnitude, making them dimly perceptible through most binoculars."

ASV Journal Vol 24 No 3 June 1971: "faint and very extended in 6-inch 64x."

10x50: "11' faint glow, 1 member resolved, averted vision reveals another 3 faint stars in the field forming a straight line." (suburban skies) [RH]

11x80: Round, ghostly presence, detached from a small star due west; the Uranometria shows it touching the cluster. (suburban skies) [AS]

6-inch f/8.6 Newtonian: I found this dim cluster while sweeping at 52x. It is an elusive clsuter at 43x, appearing as an irregular glow to the southeast of an 8th mag star. This mottled grouping of very fine stars seems gathered into an elongated bar lying NE-SW. There is one 9th mag star, the rest are about 11th mag and fainter. I estimate the Trumpler class as III 1 R. (suburban skies) [AS]

6-inch f/8.6 Newtonian: “Large delicate cluster of very faint stars on an extremely rich field. There’s one tiny star - the brightest at about 10th magnitude - which marks the southern end of an oblong patch, 7' x 1.3' in PA 25°, that contains the brightest of these dim stars. 104x is too much on this dim cluster tonight. In the sweeper eyepiece (45x, 50' field of view), the cluster appears twice as large as it vaguely merges into the background. Readily seen near the end of a chain of stars pointing to Zeta Areae.” (exurban, lim mag 6.2 naked eye; seeing good; dew!) [AS]

NGC 6215
ESO137-G046
RA 16:51:06
Dec -58°59.6'
Galaxy

h: "pretty faint, round, very gradually a little brighter in the middle, has a yellow 5th mag star preceding it, approx. 1m 19s in RA, and 3' or 4' south."

Burnham notes that Eta Arae (B-V = 1.57) lies 1.5' to the west of the galaxy.

ASV Journal Vol 24 No 3 June 1971: "just visible in 4-inch."

Thornton Page ("Galaxies and the Universe", Chapter 13 - Binary Galaxies) includes this galaxy in the NGC 6300 Group. Members include NGC 6300, NGC 6221, NGC 6215, NGC 6215A & IC 4662A. Possible members include IC 4710, IC 4713 & IC 4714.

NGC 6221
ESO138-G003
RA 16:52:46
Dec -59°13.0'
Galaxy

h: "pretty faint, large, round, gradually a little brighter in the middle, 80 arcsec across." When he observed it a second time, he mistook it for a globular cluster, describing it as "globular cluster, pretty bright, pretty large, round, gradually brighter in the middle, 2.5' across, barely resolvable." His third observation was no more successful: "globular cluster, viewed in place, but clouded over before any description could be made."

ASV Journal Vol 24 No 3 June 1971: "visible in 4-inch."

Thornton Page ("Galaxies and the Universe", Chapter 13 - Binary Galaxies) includes this galaxy in the NGC 6300 Group. Members include NGC 6300, NGC 6221, NGC 6215, NGC 6215A & IC 4662A. Possible members include IC 4710, IC 4713 & IC 4714.

Included in the CCD-atlas of Ryder S.D. & Dopita M.A. (1993) "An H-alpha Atlas of Nearby Southern Spiral Galaxies" Astrophys.J.Suppl. 88, 415. They note: "This unusual galaxy would no doubt be a lot more famous were it somewhat nearer and not so close to the Galactic equator. Optically, it is peculiar, with the northenr arm swinging back sharply and covering a full 180 degrees, while the southern arm barely gets started before fading out . . The bulk of the massive star formation in NGC 6221 is currently occuring in a supergiant complex just northeast of the nucleus, adjacent to the point where the southern arm joins the nuclear bulge . . NGC 6221 clearly needs more intensive study to understand the forces giving rise to the curious pattern of star formation in the disk."

NGC 6253
Mel 156, Cr 321, Rb 116
RA 16:59:05
Dec -52°42.5'
Open cluster

Sir John Herschel notes that this object may be Dunlop 374, which was observed by James Dunlop from Paramatta, New South Wales, and included in his catalogue of 1827. Using a 9-inch f/12 telescope, Dunlop described it as "a very faint nebula, of an irregular round figure, about 2' diameter, slightly bright towards the centre, easily resolvable into very minute stars, slightly compressed to the centre; this also precedes Epsilon Arae." Observed by Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it only as "a small triangular cluster, 2' diameter, stars of 13th magnitude."

11x80: Seen as an extended glow, fanning away from a 9th mag star attached to the west. (suburban skies) [AS]

6-inch f/8.6 Newtonian: “Just north of epsilon Areae. Evident in the sweeper (45x, 50' field of view) as a large, faint spray of dim light erupting out of a 9.5 mag star. This very rich, 3.5' cluster is generally triangular in shape and has a 9.5 mag star close southwest. The grouping is quite well separated from the background and at 144x is resolved into a host of tiny stars. About half a dozen are held directly, many others glimpsed; two stars on the southern side are much brighter, giving this grouping a modest brightness range.” (exurban, lim mag 6.2 naked eye; seeing good; dew!) [AS]

IC 4642
ESO180-PN004, PK334-09.01
RA 17:11:43
Dec -55°11.3'
Planetary nebula

Also known as Fleming 96, this planetary was discovered by Fleming at Harvard Observatory on the basis of its spectrum. He described it only as stellar.

In the catalogue by Perek and Kohoutek it is listed as PK 334-9.1, where its size is given as 18" x 15" and magnitude 12.4. The Vorontsov-Velyaminov catalogue notes that it exhibits ring structure. The planetary measures 21" across and glows at magnitude 13.3

NGC 6326
ESO228-PN001, PK338-08.01
RA 17:20:44
Dec -51°19.8'
Planetary nebula

h: "Planetary nebula. A perfectly unioform, quite round, planetary disc; like a star out of focus. A very little uncertain at the edges, like a star on a dewy unsettled calm night, when the stars look large without being decidedly ill defined. Diameter = 5 arcseconds, light = a star 9-10th mag. there is positively no bright point in the centre. It has two very small attendant stars, one 14th mag, pos from centre = 352.3 degrees, dist from edge = 3/4 diam; the other also 14th mag, pos 96.7 degrees, dist from edge = 1.5 diameter. Occurs in a field full of milky way stars. (N.B. -- Referring to the description of Dunlop 381, I see no ground to suppose that this can by possibility have been the object intended by that place and description ['an extremely faint small nebula, about 12 arcseconds diameter, with a bright point in the centre']. At all events, the remarkable planetary character has escape notice by the author of that description) See fig 6, plate VI." On a second occassion he called it "planetary nebula, delicate, F, vS, diam = 6 or 7 arcseconds, .exactly round, perfectly uniform (as respects the graduation of the light from the centre to the edges), but the light a very little curdled. Not the slightest haziness, but like a star out of focus. x320 shows rather more fur at the edges than I think it would to a planet of equal size and light. Its light is = a star 10-11th mag. It would be quite useless to look for this object under favourable circumstances -- of instrument and sky. A night of gloriously perfect definition! It is in a very rich place. there are 40 or 50 small stars in field. Measures of the two companions; 1st pos = 351 degrees, dist = 1 diam from edge, star = 14th mag; 2nd pos = 91.4, dist = 2/3 diam, star = 13th mag. Showed it to my attendant, J.S., who saw it well" Later he wrote: "Viewed. I can barely discern that the attendant stars are as in [description above], but it is so faint that (the stars being all blotty and dreadfully defined) I could not be sure it was the object, till too late to take its RA and PD on the wires. However, it was just in the middle of the field at the time expected, and set to the place at once."

Hartung notes "This small round nebula is quite conspicuous in a star-sprinkled field; it is fairly well defined and brighter towards the centre, and two stars are very close north and following. The nebula is 25 arcsec across".

Sanford calls it a "small round planetary nebula with two stars nearby."

6-inch f/8.6 Newtonian: “Just north-east of two 8th magnitude stars, appears as a very small, round, grey glow, clearly non-stellar at 104x, probably so at 48x.” (exurban, lim mag 6.2 naked eye; seeing good; dew!) [AS]

ESO180-PN007
Wray 16-266
RA 17:22:36
Dec -52°46.6'
Planetary nebula