Some Dunlop Objects

[glenc (Glen)]

I thought I would combine some James Dunlop descriptions with images from IIS people.
James Dunlop observed from his back yard in Parramatta, Sydney with a homemade 9" aperture f/12 speculum reflector in 1826.
He was a typical Aussie battler, a poor man with little education. I think he did a great job.

Here is the first Dunlop object.
He found the galaxy Dunlop 482 = NGC 5128 = Cen A and wrote; "A very singular double nebula, about 2.5' long, and 1' broad, a little unequal: there is a pretty bright small star in the south extremity, of the southernmost of the two, resembling a bright nucleus: the northern and rather smaller nebula is faint in the middle, and has the appearance of a condensation of the nebulous matter near each extremity: These two nebula are completely distinct from each other, and no connection of the nebulous matters between them. There is a very minute star in the dark space between the preceding extremities of the nebula: they are extended in the parallel of the equator nearly."

This image is by Fred Vanderhaven aka Bassnut.
http://fredsastro.googlepages.com/NG...full;init:.jpg

[glenc (Glen)]

Dunlop described the nebula Dunlop 322 = NGC 3324 (near eta Car) as;
"A star of the 7th magnitude, involved in faint nebula."

Here is another image by Bassnut.
http://fredsastro.googlepages.com/G1...NBsml-full.jpg

[Ric]

Great descriptions combined with some lovely images.

Very nice Glen.

[glenc (Glen)]

So far I have included one galaxy and one nebula, it is time for a planetary nebula.
Here is the picture by Frank aka Spearo.
http://www.iceinspace.com.au/forum/a...3&d=1156406166
and this is Dunlop's description.
D252 = NGC 5189 "A very faint nebula, about 25" diameter. It is very near a star of the 8th magnitude, and near the north following extremity of a crescent of very small stars."
The crescent of stars is in the lower left part of Frank's image.

[glenc (Glen)]

Dunlop described the GC D265 = NGC 2808 as "A very bright round nebula, about 3’ or 4' diameter, very gradually bright to the centre. This has a fine globular appearance"
This image is by Terry B.
http://www.iceinspace.com.au/forum/a...7&d=1200918388

[glenc (Glen)]

Bill Christie took this image of D360 = NGC 6067.
http://www.iceinspace.com.au/forum/a...0&d=1149005438
Dunlop described this OC as "A pretty large cluster of small stars of mixed magnitudes, about 12’ diameter; the stars are considerably congregated towards the centre, extended south preceding and north following."

There is an interesting PN Menzel 2 = PK 329.3-02.8 near the above OC. It is mag 12.5 and 27" across.
To find it go 25' south from the OC to the orange mag 5 star kappa Nor then continue 21' in almost the same direction.

[glenc (Glen)]

"DUNLOP, JAMES (1793-1848), astronomer, was born on 31 October 1793 at Dalry, Ayrshire, Scotland, the son of John Dunlop, weaver, and his wife Janet, née Boyle. After primary level his education was at night-school in Beith where he worked in a thread factory. He was constructing telescopes at 17, and some ten years later an acquaintance with Sir Thomas Brisbane developed his interest in astronomy. When appointed governor of New South Wales, Brisbane resolved to establish an observatory, and chose Dunlop and Carl Rümker as assistants. They arrived in Sydney on 7 November 1821 and the instruments were set up in Parramatta in time to observe the solstice. A building was erected and regular observations began in May 1822. Apart from making the greater part of the observations for a catalogue of stars, Dunlop made observations of the length of the pendulum, the results of which were published with those of Captain Henry Kater in Philosophical Transactions of the Royal Society, 1823. In June 1822 Dunlop was the first to see the reappearance of Encke's comet. This was only the second case of the predicted return of a comet being verified, the first being that of Halley in 1758.
From June 1823, when Rümker left the observatory, to February 1827 was a busy period for Dunlop: he made about 40,000 observations which form the basis of the Parramatta Catalogue of Stars and, with an instrument built by himself, made the observations for his catalogues of nebulae and star clusters, and double stars. He then returned to Scotland to work in Brisbane's private observatory at Makerstoun in Roxburgh.
In 1831 Dunlop was appointed superintendent of Parramatta Observatory, which had been taken over by the government. He found the equipment and buildings of the observatory in bad condition, and had to exert much effort to restore them. In the period to 1835 he reported observations of asteroids, planets and comets in Memoirs of the Royal Astronomical Society. He made many transit observations, particularly with the new transit circle by Jones which he installed in 1835. He gave help and advice to Major (Sir) Thomas Mitchell when he was preparing his expeditions in 1831 and 1834. However, from about 1837 Dunlop appears to have been in ill health, his activity declined and the transit work done from 1832 at Parramatta was never reduced or published. He resigned and retired to his farm on Brisbane Water in August 1847 and died on 22 September 1848. His wife, Jean Service, whom he married in 1816, survived him for eleven years. They had no children..."
http://www.adb.online.anu.edu.au/biogs/A010322b.htm

See also: http://www.austehc.unimelb.edu.au/fam/1527.html
and: http://nla.gov.au/anbd.bib-an10670779

[glenc (Glen)]

Dunlop found the 5 objects below and he also was the first to see the galaxy D411 = NGC 4945. Here is an image from Garyh http://www.iceinspace.com.au/forum/a...0&d=1207540295 of the object Dunlop described as:
"A beautiful long nebula, about 10' long, and 2' broad, forming an angle with the meridian, about 30° south preceding and north following; the brightest and broadest part is rather nearer the south preceding extremity than the centre, and it gradually diminishes in breadth and brightness towards the extremities, but the breadth is much better defined than the length. A small star near the north, and a smaller star near the south extremity, but neither of them is involved in the nebula. I have strong suspicions that this nebula is resolvable into stars, with very slight compression towards the centre. I have no doubt but it is resolvable. I can see the stars, they are merely points. This is north following the 1st xi Centauri."
It is resolvable but I don't think Dunlop resolved it! The mag 11 galaxy NGC 4976 is 30' following.

[glenc (Glen)]

In 1826 Dunlop described D564 = NGC 2818 as "A pretty large faint nebula of a round figure, 6' or 8' diameter; the nebulosity is faintly diffused to a considerable extent. There is a small nebula in the north preceding side, which is probably a condensation of the faint diffused nebulous matter; the large nebula is resolvable into stars with nebula remaining."
Terry B took this image: http://www.iceinspace.com.au/forum/a...3&d=1201867222

[glenc (Glen)]

Paul Mayo (PhotonCollector) took this image of D 332 = NGC 3199.
http://www.iceinspace.com.au/forum/a...1&d=1148114670

James Dunlop wrote "A very faint ray of nebula, about 2' broad, and 6' or 7' long, joining two small stars at the south following extremity, which are very slightly involved, but their lustre is not diminished from that of similar small stars in the field. The north extremity also joins a group of small stars, but they are not involved. Figure 15."
http://www.iceinspace.com.au/forum/a...3&d=1210454078
Note Dunlop’s position is exactly 1 degree north of N3199, a copy error. The description and figure match N3199. The figure has south at the top.

[glenc (Glen)]

The globular D445 = NGC 3201 has a low concentration.
Clive (Alchemy) took this image: http://www.iceinspace.com.au/forum/a...1&d=1204275793

Dunlop's description was "A pretty large pretty bright round nebula, 4' or 5' diameter, very gradually condensed towards the centre, easily resolved into stars; the figure is rather irregular, and the stars are considerably scattered on the south preceding side: the stars are also of slightly mixed magnitudes."

The PN NGC 3132 is 6.3 degrees north (pa 163). Brian Warner notes that Dunlop recorded this as “Dusky Yellow – a fine Planetary disc” in his star catalog but did not included it in his Catalogue of Nebulae and Clusters of Stars in the Southern Hemisphere observed in New South Wales.
http://seds.lpl.arizona.edu/messier/...ar/dunlop.html

[glenc (Glen)]

Mike (Iceman) took this image of the OC D297 = NGC 3114: http://www.iceinspace.com.au/forum/a...7&d=1205264951

It is "A beautiful cluster of stars, arranged in curvilinear lines intersecting each other, about 40' diameter, extended south preceding, and north following." according to its discoverer, James Dunlop.

This naked eye cluster was, surprisingly, not included in Nicolas Lacaille's 1752 catalog.
http://seds.org/MESSIER/xtra/history/lacaille.html

The Dunlop catalog is sorted from south to north in declination order, not by RA like most modern catalogs.
D1 is the most southerly object and D629 the most northerly.

[glenc (Glen)]

“If men like [John] Herschel are to spend the best years of their lives in recording for the benefit of a remote posterity the actual state of the heavens…what a galling discovery to find amongst their own contemporaries men [James Dunlop] who … from carelessness and culpable apathy hand down to posterity a mass of errors …[so] that four hundred objects out of six hundred could not be identified in any manner … with a telescope seven times more powerful than that stated to have been used!”[1]

[1] James David Forbes, ‘Results Results of Astronomical Observations made during the years 1834, 5, 6, 7, 8 at the Cape of Good Hope, being a completion of a telescopic survey of the whole surface of the visible heavens commenced in 1825’, The Quarterly Review, 85, 1849, pp 1-31.

[glenc (Glen)]

John Herschel wrote:
“Of the objects remaining, 135 are nebulae and clusters of my Father's catalogues, now, for the first time, re-observed; 9 are Messier's, 5 of which are identical with objects catalogued by Mr. Dunlop; and 206 others have also been identified, with more or less certainty (indicated by the absence or presence of the sign ?), with objects observed by Mr. Dunlop, and described in his Catalogue of Nebulae. The rest[1] of the 629 objects, comprised in that catalogue, have escaped my observation; and as I am not conscious of any such negligence in the act of sweeping as could give rise to so large a defalcation, but, on the contrary, by entering them on my working lists (at least, until the general inutility of doing so, and loss of valuable time in fruitless search, thereby caused it to become apparent), took the usual precautions to ensure their rediscovery; and as I am, moreover, of [the] opinion that my examination of the southern circumpolar region will be found, on the whole, to have been an effective one, I cannot help concluding that, at least in the majority of those cases, a want of sufficient light or defining power in the instrument[2] used by Mr. Dunlop, has been the cause of his setting down objects as nebulae where none really exist. That this is the case, in many instances, I have convinced myself by careful and persevering search over and around the places indicated in his catalogue.”[3]

[1] 418 objects = 66.5%
[2] The original footnote says, “A 9-inch Newtonian reflector, of 9 feet focal length, which, in point of light, would correspond to about one-seventh of that used in my [John Herschel] sweeps. That such was its construction, I conclude from the mention of the large mirror in Philosophical Transactions, 1828, p.113.”
[3] J. Herschel, Astronomical Observations, p. 3.

[glenc (Glen)]

Greg (gregbradley) created this image of D262 = NGC6744: http://www.pbase.com/image/96539963

In 1826 Dunlop discovered "A pretty large very faint nebula, about 5’ or 6’ diameter, slightly bright towards the centre; a minute star is north of the nebula, and two stars of the 7th magnitude preceding."

This galaxy is visible in 20x80 binoculars and has a low surface brightness.

[glenc (Glen)]

Nicolas Lacaille missed this bright globular and Dunlop saw it as "A pretty large and very bright nebula, 5’ or 6’ diameter, irregular round figure, easily resolved into a cluster of small stars, exceedingly compressed at the centre. The bright part at the centre is occasioned by a group of stars of some considerable magnitude when compared with those of the nebula. I am inclined to think that this may be two clusters in the same line; the bright part is a little south of the centre of the large nebula."

This image of D295 = NGC6752 was taken by Michael Samerski (smersh):
http://www.metronome-trading.com/me/ngc_6752.htm

NGC 6752 is only 3.8 degrees north of NGC 6744.
Both are visible in Roger Groom's (rogerg) image:
http://content.rogergroom.com/cms/000775.jpg

[glenc (Glen)]

D25 = NGC346 is the brightest nebula in the SMC. It lies between the GC NGC330 and the OC NGC371.

Eric Lo (EzyStyles) took this image of 330 (top right) and 346.
http://www.iceinspace.com.au/forum/a...6&d=1191567520

Jason Jennings (jase) took this image of the SMC http://cosmicphotos.com/gallery/imag...ld_album_id=12.

Dunlop described D25 as "A pretty large pretty bright nebula, about 2.25 ' diameter, irregular round figure, resolvable, very slight condensation, not well defined at the edges."

His 9" aperture speculum reflector telescope had a limiting magnitude of 13 and was equivalent to a modern 6.5" Newtonian.

[glenc (Glen)]

This is D606 "A faint nebula, about 1.25' long and 30" or 40" broad, with a considerable brightness near each end, and faint in the middle, resembling two small nebulae joined." according to Dunlop.
I am not certain that Dunlop saw this and your comments are welcome.

Tony (Striker) took this image: http://www.iceinspace.com.au/forum/a...2&d=1158142906

[glenc (Glen)]

D413 is "A cluster of small stars, with a bright star in the preceding side. A very considerable branch or tail proceeds from the north side, which joins a very large cluster."

This OC in is the nebulae NGC 6188 which was imaged by Paul Mayo (PhotonCollector) http://www.iceinspace.com.au/forum/a...4&d=1190883235
The cluster is on the right in the image. The nebulae was found by John Herschel, it is an easy object in a 12" scope with a UHC filter.

[glenc (Glen)]

Steven Juchnowski (sjastro) posted this image of D 507 = NGC 55
http://users.westconnect.com.au/~sjastro/ngc55c.html
NGC 55 is visible in a 50mm finder.

Dunlop discovered "A beautiful long nebula, about 25' in length; position north preceding, and south following, a little brighter
towards the middle, but extremely faint and diluted to the extremities. I see several minute points or stars in it, as it were through the nebula: the nebulous matter of the south extremity is extremely rare, and of a delicate bluish hue. This is a beautiful object."
He saw it 182 years ago on Fri 7/7/1826 at 5:05am with his 9" reflector. He also discovered NGCs 134, 7552 and 7582 that night.
Imagine discovering 4 galaxies in one night!