Alexander suggested a thread called Dunlop Month. Here it is.
James Dunlop cataloged clusters and nebulae from his backyard in Parramatta in 1826.
He was the second person to make a catalogue of southern deep sky object (DSO).
Nicolas-Louis de La Caille made the first catalogue in 1751-52 from Cape Town with a half inch refractor.
James Dunlop built his own 9" speculum reflector and found five times more objects than Messier. Messier used 7.5" and 8" reflectors.
Unfortunately Dunlop has been ignored over the years. He was a great observer.
Prior to 1840, William Herschel, John Herschel and James Dunlop discovered most of the NGC objects.
This IIS thread includes 172 Dunlop objects outside the Magellanic Clouds.
The attached file is an 11 page biography of James Dunlop.
It is a chapter from a PhD thesis with the images removed so that the file is not too large.
Here are some pictures of Dunlop and Rumker http://picasaweb.google.com/dunlop1826/DunlopRumker#
The attached list contains 172 Dunlop DSO.
It can be opened with MS Excel or similar programs.
The columns in the spreadsheet are: Dun, NGC/IC, Notes, Type, Const, Vmag, Size, RA 2000, dec, Month @ 10pm Dun - Dunlop number
NGC/IC number
Notes - there were some copy errors when the typed catalog was made.
Type - OC, GC Neb, Dark neb, PN, MW patch, Gxy
Constellation
Vmag - Visual magnitude
Size in arcmin (arcsec for PN)
RA - Right Ascension for 2000
declination
Month when the object transits at 10pm (11pm DST)
Sixteen of Dunlop's open clusters are not NGC or IC objects.
They are from:
Mel: Melotte (1915)
Tr: Trümpler (1930)
Cr: Collinder (1931)
Mrk: Markarian (1951)
Lynga (1964)
Ru: Ruprecht (1966) and
H: Harvard (1979)
Dunlop actually found these OC first, before they were listed in the above catalogs.
The attached SkyMapPro map will help you find 3 of the November Dunlop DSOs. IC 1633, NGC 613 and NGC 986.
The map is about 26 degrees high and shows the sky at about 10pm DST in early November.
Thats a lot of info in 24 hrs!
Cool!
still sifting through it...
At first I thought it was a new nebula that looked like a tyre or tyre tread!!!!!
Sorry hehehehe
Bartman
That's a good idea Glen. It really deserves a thread of its own.
Just wondering who would qualify as a "suitably qualified second party" if there was no astronomy club nearby. I hereby promise to keep the Argo off when I start on the list!!
I'll be happy to check your list Paul!
I compared 4 Dunlop galaxies this morning with a 12" scope and 8mm EP (190x, 25' field).
From brightest to faintest they were: N613, N986, N625 and IC1633.
The first three are elongated and the first two have bright cores.
IC1633 is vF and vS. Is it visible in a 6"? Images are at http://picasaweb.google.com/dunlop1826/Dunlop28#
The GC N362 is vB and vL. It is resolvable even at the core.
I also saw a fantastically bright meteor moving vertically down near beta Ceti and I looked at Comet Hartley.
The comet is easy to see in a 50mm finder and is about 15' in diameter in the 12" scope using an 8mm EP.
The rich, well educated, upper class astronomers in England were critical of Dunlop in his day.
Dunlop was a poor, uneducated, lower class Scot.
But I have to admire Dunlop after looking at some of his faint galaxies.
Dunlop DSO for December
21 of the 172 Dunlop DSO transit at around 10pm in December. (11pm DST)
The first is a GC the other 20 are galaxies.
NGC Type Con Vmag, Size (arcmin)
1261 GC Hor 8.3, 6.9
1269 Gxy Eri 8.5, 11.1, also known as NGC1291
1313 Gxy Ret 9.2, 9.1
1316 Gxy For 8.5, 12.0
1317 Gxy For 11.2, 2.8
1350 Gxy For 10.7, 5.2
1365 Gxy For 9.6, 11.2
1380 Gxy For 10.2, 4.8
1433 Gxy Hor 10.1, 6.5
1487 Gxy Eri 11.9, 2.0, Dunlop's faintest galaxy
1493 Gxy Hor 11.4, 3.5
1512 Gxy Hor 10.6, 8.9
1515 Gxy Dor 11.4, 5.2
1527 Gxy Hor 11.0, 3.7
1532 Gxy Eri 10.6, 11.1
1543 Gxy Ret 10.3, 4.9
1553 Gxy Dor 9.4, 4.5
1559 Gxy Ret 10.7, 3.5
1566 Gxy Dor 9.8, 7.0
1617 Gxy Dor 10.7, 4.3
1672 Gxy Dor 10.2, 6.6
The 3 attached SkyMap Pro maps will help you find the Dunlop December DSO.
Map a shows Canopus and Achernar.
Map b shows the Fornax galaxy cluster. The 3 bright stars near 1436 are f, g & h Eri. (left, top, right)
Map c shows the bright star alpha Dor below 1617 and alpha Ret near 1559.
This is remarkable work you are carrying out here, Glen.
I think that this would be worthy of a combined Imaging and Obs. Challenge effort to put the spot light on Dunlop's work. Maybe shot off a PM to DavidTrap who organises the DSO imaging Challenge.
There is so much material. Surely a shared theme is possible. Would almost be like the current Arp galaxy book where amateurs have photographed the Arp galaxies. Only it would be the "Dunlop Catalogue".
NGC 1261, Dun 337, JH 2517 GC in Hor, mag 8.3, size 6.9’, RA 3.204, dec -55.20
Distance 53,500 light years
This GC seems brighter than mag 8.3 to me (GC)
NGC 1261 is 13 deg east of Achernar, see maps a and c in post 15.
Other GC at this time of the year are: NGCs 104, 288, 362, 1851, 2298
Descriptions
On 28/9/1826 Dunlop discovered NGCs 1261 (at ~2:40am), 1433, 1527 and 1553 (at ~3:45am)
Moonrise (18%) was 3:00 am and astro-twilight 4:15 am. (not DST)
(Parramatta house was at latitude 33.82S and longitude 151.00E)
Dunlop 337 “A very bright round nebula, about 1.5’ diameter, pretty well defined and gradually bright to the centre. A small star north following.” [star mag 9.1] http://picasaweb.google.com/dunlop18...28570659595186
John Herschel (JH) 2517: 5/12/1834 "bright; large; irregularly round; 2.5' diameter; all resolved into equal stars 14 mag.
Has a star 9th mag 45 N.f. 3' distant." [m9.1, pa 54, 3.6’]
His second observation recorded it as "pretty bright; round; very gradually brighter in the middle; 3' across; resolved into stars of 15th magnitude. A very faint nebula (??) precedes." [there is no nebulae preceeding, GC]
Hartung notes: “This well condensed globular cluster lies in a fine field; 30cm resolves it into crowded stars right to the centre. It is about 2.5’ across and the scattered outliers do not extend far; the stars are however very faint and hard to detect with 20cm although the cluster looks granular. It is a fine bright object, conspicuous with 10.5cm.”
See Auke Slotegraaf http://www.fortunecity.com/roswell/borley/49/u419.htm#NGC1261
NGC 1553, Dun 331, JH 2630 Gxy in Dor, mag 9.4, size 4.5’, RA 4.270, dec -55.78
Distance 70 million light years? (the average of 5 measurements is 47.7 Mly)
Discovered by Dunlop on Thursday 28/9/1826 at about 3:45am
Located 2d 37m west (pa 252) of mag 3.3 alpha Dor
See map c in post 15
Nearby galaxies include NGCs 1549, 1566 and 1617
Note. In Dunlop’s printed catalogue the RA was out by 1 hr but the RA is correct in his notes.
He missed NGC 1549 which is next to NGC 1553. I think this was because his scope probable had dew on it at the end of the mornings observing run.
The notes are available on microfilm from the national library in Canberra. Reel M 1709 http://catalogue.nla.gov.au/Record/7...tronomer%20%23
John Herschel’s Description JH 2630: [his 18.5" scope was equivalent to today's 16"]
5/12/1834. vB, R, gmbM, 60", between 3 stars;
6/12/1834. B, R, in a triangle formed by 3 stars
Hartung’s Description
“In this field are two bright nebulae [NGC 1549 and NGC 1553] about 13’ apart . . one is round, about 1.5’ across with very bright nucleus; the other is elliptical, about 2’ x 0.8’ in pa 150 deg, strongly concentrated and even brighter. 7.5cm shows these nebulae plainly.” http://www.fortunecity.com/roswell/b...20.htm#NGC1553
NGC 1350, Dun 591, JH 2545 Gxy in For, mag 10.7, size 5.2’, RA 3.519, dec -33.62
Distance 73.5 Mly, average of 2 measurements
James Dunlop found NGC 1317 and NGC 1350 on the night he finished observing for his catalogue, 24/11/1826.
He started his catalogue just 7 months earlier on 27/4/1826.
Messier took much longer to catalogue 103 objects; he started his catalogue in 1758 and completed it 23 years later in 1781.
