Lacaille III.8

Historical observations

Lacaille (1755)

This cluster was discovered by Lacaille and included in his 1755 catalogue as Class III No. 8. In his half-an-inch 8x telescope he saw it as "two stars in nebulosity."

Dunlop, James (1827)

James Dunlop observed it from Paramatta, New South Wales, and included it as No. 342 in his catalogue of 1827. Using a 9-inch f/12 telescope, he described it as "A group of small stars of the 11th and 12th mag, with a multitude of minute stars mixt, extended S.p. and N.f."

John Herschel

Observed by John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as a "large, pretty brilliant, coarse, scattered cluster of Class VII which more than fills the field; 50 stars more or less 9..12th mag; chief star 7th mag, somewhat insulated, taken for place of cluster." On a second occasion, he noted the "place of a red star, the chief and centre of a fine bright but not rich cluster of about 30 stars 9..13 mag. This red or high yellow star is 8th mag."

Published comments

Melotte, P.J. (1915)

A catalogue of star clusters shown on Franklin-Adams chart plates. Mem.R.A.S., 60(5), 175-186.

Raab, S. (1922)

Raab, S. (1922) A research on open clusters. Lund Medd. Astron. Obs. Ser. II, 28, 1.

Discussed, based of F-A plates.

Doig, P. (1925)

Journal BAA, 36(3), Dec, p91

irr. cluster with a few B*; about 30' diam.

Doig, P. (1926)

Doig, P. (1926) "A Catalogue of Estimated Parallaxes of 112 Nebulae, Open clusters and Star Groups", Vol 36 (4), p 107-115.

"irregular; loose; in rich region." He gives the approx. diameter as 25 arcmin.

Hogg, A.R. (1965)

"Cat. of Open Cl. south of -45° Decl.", Mem. 17 Mnt Stromlo Obs.

Vogt, N. & Moffat, A.F.J. (1972/3)

Vogt. N. & Moffat, AFJ (1973), "Southern Open Star Clusters III." Astron.Astrophys.Suppl., 10, 135-193. [image, table]

d = 0.58kpc, earliest Sp = B7.

Union Observatory Circular (c.1919)

Described in Union Obs. Circulars, 45-76, p 50. "Nebulae, clusters, etc. on Sydney Plates" as "Centre of an aggregation of stars, 9 - 13 mag.."

Trumpler, R.J. (1928)

Trumpler (Lick Obs Bul, Vol 14, No. 420) gives the diameter as 15' and the class as 2 3 pE.

Bailey, S.I. (1908)

"cluster, coarse."

Bailey, S.I. (1908) A catalogue of bright stars and nebulae. Ann.Harv.Coll.Obs., 60(8), 199.

Sulentic & Tifft (1973)

The RNGC (Sulentic and Tifft 1973) notes that this is a 7.5 mag open cluster.

Burnham's Celestial Handbook

Burnham calls this open cluster in Centaurus large, pretty rich, slightly compressed, about 30 stars of 9th mag and fainter.

Modern observations

Brian Skiff

M&V?: * on W is HD127753; V=7.02/1.86 (K5III var)

15cm - lg elong cl sparsely populated; m7 lucida on W. 80x shows 75 *s in

25'x12' area elong NE-SW. concen grp nr center 8' across, and additions

NE&SW. BS, 26Feb1990, LCO.

Contemporary observations

Auke Slotegraaf

1980

8x40 binoculars show this as a loose, small, poor cluster, four stars visible (one isolated, the other three forming a triangle.)

1994 February 23

1994-02-23, 00:30, Jonkershoek, 11x80 tripod-mounted, strong moonlight. This cluster appears obvious, even in strong moonlight, as an elongated glow with stars.

1998 April 24

1998-04-24/25, 11x80 tripod-mounted binoculars, Die Boord. Seeing average, transparency below average, dew. "B, vL, mE NNE-SSW, clearly resolved into stars. Stars of mixed magnitudes. One bright orange one, a few mediums, and many small stars. There are two triangular gorups, back to back, with a clear gap between them. The north-eastern triangle is marked on the U-chart as the cluster; here are at least six stars that are directly seen, and several others imagined. While sweeping the area, my eye is immediately drawn to this much elongated swathe of stars, almost like a pair of sweeping wings."

Gary Lillis

2008 April 24

2008 April 24, 20:20

Walmer, Port Elizabeth

2.5-inch f/7.6 refractor (EP: 25mm 28x 45arcmin fov)

Conditions: Clear, quite good, quite stable.

Size=12arcmin, V=5.5. Hard to find, larger than I thought; occupies 20arcmin of the field of view. Does appear to have a rich characteristic of about 13 stars, although a faint cluster. Stars range from M8.1-19., with a red/orange star M10. A slightly concentrated patch running south-to-noth toward the centre, otherwise dark empty spaces on both the east and west side within the cluster. NGC 5662 us too faint to focus on sufficiently with the 12.5mm (56x) eyepiece. There are a number of well placed neighbouring field stars: southeast 22arcmin M8.1, further southeast 38arcmin M7.2, southwest 17arcmin M8.4 and a bright M6.9 HD 127297 26arcmin northwest.