U 399
10:00 to 10:48
-39° to -50°
Ant, Vel
Feb - May

THIS MAP COVERS the eastern reaches of the Sails, unfurled beneath the flowing tail of the Centaur. Oddly, Lacaille's planisphere shows the mast of the ship apparently broken, or at least bent at right angles, so that it sweeps back parallel to the body of the ship.

Two showpiece objects appear on this map: the globular cluster NGC 3201 and the Eight-Burst nebula NGC 3132.

FEATURED OBJECTS: NGC 3201, NGC 3132, NGC 3283.

NGC 3201
Bennett 44
RA 10:17:36.8
Dec -46° 24' 40''
Globular cluster

Discovered by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "globular cluster, irregularly round, gbM, not v m comp, 6', resolved into stars 13...15th mag." On a second occassion he called it "irregularly round, 7' diameter, but the outliers extend to at least 10' or 12'; gpmbM, but not very much compressed; all resolved into stars 13..16th mag."

Phil Harrington calls it a "loose stellar concentration." He notes that "the feeble form of this 7th mag globular cluster becomes readily apparent when viewed through 6- to 8-inch telescopes, as many of its 13th mag members are immediately resolvable around the core. Observers also report a noticeable clumping of stars along the cluster's northern edge, though photographs show no evidence of this."

W. S. Houston notes that his 4-inch shows this cluster well as it is fairly bright and about 8' in diameter.

11x80: Under pristine skies, binoculars show this as a splendidly large, diffuse globular cluster. Its soft glow lies just outside of the main stream of the Vela milky way, on a field very rich in large and small stars. The cluster, while very large (about 10'?), appears very diffuse, with a broad centre and only a narrow fringe. Overall, the cluster appears as large as the brighter inner region of Omega Centauri.
Good, dark suburban skies show an easy, bright fluff of cotton-light in a very rich field. The total light of the cluster, spread out over 11 arcmin, gathers gradually into a broad centre, just under 7' across. An easy, attractive object. Not one of the small-nucleated globulars; rather like a nebulous fuzzy coin.
Under more mediocre skies, observing in strong moonlight, this cluster is reasonably bright, large and extended, but is still easy to see.
Note that the large size shown on the Uranometria chart is quite misleading. [AS]

NGC 3132
Bennett 43
Eight-Burst Nebula
ESO316-PN027, PK272+12.01
RA 10:07:00
Dec -41° 19.6'
Planetary nebula

Discovered by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it on Sweep No. 554 as "Planetary nebula, very large, very bright, elliptic; has in it a 9th mag star somewhat excentric. Its light is exactly equable, ie. not increasing towards the middle; yet I cannot help imagining it to be closely dotted. It is just like a star out of focus in certain states of the mirror and atmosphere. Three stars near, a = 9th mag; b = 9th mag; c = 14th mag; A very extraordinary object." On the next sweep, it was "well seen, as described in Sweep 554, and shown to Mr. Maclear and another gentleman. The star in the nebula is 9th mag, very sharp, full and distinct. Six stars 9th mag in the field; one companion = 13th mag." On the next occasion he called it "a perfectly well defined bright elliptic disc, diam. in RA = 4 seconds; major axis : minor axis about 5 : 4. In the middle is a 9th mag star, which is quite sharp, but which I think has a small disk. This star is somewhat excentrically placed." His final observation was recorded as "Planetary nebula with a 10th mag star in centre; very bright; very well defined, and perfectly equable all over in light, there being no condensation up to the centre. The star is sharp, the nebula velvety, or like infinitely fine dust; a star 14th mag at a distance rather more than a radius of neb from edge (by diagram); has its position from centre = 333.8°." He sketched this and other planetary nebulae, commenting: "[these] represent planetary nebulae, a class of special interest, and of which, considering their general rarity, the southern heavens have afforded a rather unexpectedly large harvest. Those only are here delineated which have either accompanying stars, or which are distinguished by some peculiarity, as ... [NGC 3132] which has a star or a small disc near its centre; ..."

Hartung notes that "the central star is prominent in this bright white annular planetary nebula about 30 arcseconds across in a field of scattered stars. The light appears even without any of the bluish tint usual with planetary nebulae."

Burnham calls it "remarkable, very bright, large, slightly elongated, 8.2 mag; 84x52 arcseconds; 10th mag star in centre; 'Eight-Burst' nebula. ... Fine planetary nebula, located squarely on the Vela-Antlia border ... more or less comparable in size to the Ring Nebula in Lyra, NGC 3132 appears more conspicuous visually than the Ring, owing to the presence of the unusually bright central star ... the disc of the nebula is noticeably elliptical, measuring 84 x 52 arcseconds on photographs, with much diaphanous detail and a structure suggesting the appearance of several oval rings superimposed and tilted at different angles. From the complex structure on photographs it has been called the 'Eight-Burst' nebula ... In a recent study (1977) it was found that the 'central star' (HD 87892, mag 10, A0) is not truly the illuminating star of the nebula; the radiation instead is supplied by a 16th mag dwarf companion 1.65 arcseconds distant..."

Harrington writes that "Vela contains one of the brightest planetary nebulae in all the heavens ... NGC 3132 shines conspicuously at 8th mag and is comparable in size to the Ring nebula in Lyra. The unusual multiloop structure ... has led astronomers to nickname it the Eight-Burst nebula. Although this configuration may not be apparent through your telescope, a slight bluish tint should be. Its central star glows at 10th magnitude, making it visible in small telescopes."

Terzian notes that the central star of this planetary is a visual binary [Terzian, Y. (1980) Q.J. R.astr.Soc vol 21, p82-92].

Houston notes that this planetary lies on the northern border of Vela. "At 8th mag and roughly 1' across, it appears stellar at very low power, but at 50x or more its disk becomes apparent. A magnification of 100 on a 6-inch shows this planetary when conditions are right."

Steve Coe, observing with a 13" f/5.6, notes: "Bright, large, elongated 1.5 X 1 in PA 15, much brighter in the middle with a stellar nucleus at 150X. This is a very nice planetary with a 10th mag central star that is obvious at all powers. Averted vision makes the nebulosity grow around the star. I have seen this nebula as either grey or light green on every occaison I have observed it."

11x80: Easily seen in handheld binoculars as a faint 9th mag glow on a field well-sown with similar stars. The planetary forms the northern tip of a lazy-W of five 9th mag stars, which extends southwards from the nebula. [AS]

13.1-inch f/4.4 Newtonian: "With 37x it appears as a diffuse star located in the interior of a spiral formed by about nine stars of 9th magnitude. At 229x (14' fov) it appears large (60'') and it has a central star of 9th or 10th magnitude, which is surrounded by a dark ring within the nebulosity. This nebulosity is very bright. The northern border appears more diffuse and seems open. Some six bright stars (9th mag) dominate the 21' field. To the north-northwest is a dim star 1' from the border of the nebula." [9.7mm S.Plossl, 151x, 21' fov, sketched] (urban) [GG]

13.1-inch f/4.4 Newt., 9.7mm S.Plossl, 151x, 21’ fov. Gabriel Giust, Martinez, Buenos Aires, Arg.. North up, east left.

NGC 3283
RA 10:32:54
Dec -46° 05.0'
Galaxy?

Discovered by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "pF, S, R, gbM, 25 arcseconds; R.A. coarsely taken by an auxiliary star."

The RNGC (Sulentic and Tifft 1973) notes that this is a unverified southern object.

Double Stars

Upsilon Velorum, Rmk 11 Very unequal double star (3rd and 6th). The primary is a pale yellow colour. Easy at 144x.
To the south-east lies another cute double (can't find this star in the SAC database); these two pairs (all four stars) are in a row. This pair is wider than Rmk 11, and can be seen in the sweeper eyepiece. At this low power (40x) the small companion of Rmk 11 remains hidden in the image of the brighter star.