BULLETIN Du Canada Supplement to Volume 90/5&6 of the Journal of the Royal Astronomical Society of Canada
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October/December octobre/décembre 1996 Volume 6 Number 5&6 The Royal La Société Astronomical Society Royale d'Astronomie of Canada BULLETIN du Canada Supplement to Volume 90/5&6 of the Journal of the Royal Astronomical Society of Canada sky observing lists beyond that of Messier] have An unusual feature of Moore’s catalogue is Reflections: gained wide popularity.” This too is in spite of the the fact that the objects are listed in order of fact that the Finest NGC Objects list, an excel- declination, rather than in the conventional way, The Caldwell Catalogue: lent compilation of deep-sky targets, has ap- by right ascension, or by constellation. CaIdwell Why All the Hype? peared in our society’s Observer’s Handbook objects found in the same constellation may be since 1981. The remarkable world-wide circula- many numbers apart; for example Cygnus con- Leo Enright tion of this handbook has made this list available tains, C15, C19, C20, C33 and C34. C9 is at Kingston Centre for the last sixteen years. right ascension 22 hours, indicating that it is a One would expect that the CaIdwell list would late summer or autumn object; but so are C30 Less than a year ago, amid considerable contain 109 objects that any of us could observe and C63. The only advantage to listing objects fanfare, the CaIdwell Catalogue made its ap- from our location, given a suitable instrument in order of their declination would seem to be pearance. It was an attempt by the famous and a dark site—probably within a two-hour that it gives an indication of how many objects on British amateur, Patrick Moore, to provide fellow drive for those who live under light-polluted the list may be seen from a given latitude. astronomers with a list of what he considered to skies. Not so. Moore himself admits that only As stated previously, readers of the Observ- be the sky’s finest observing targets beyond the sixty-seven of the objects can be seen from his er’s Handbook have had access to “lists be- Messier list. Sky & Telescope devoted six own location at latitude 51°. A simple calculation yond the Messier objects” for years. Thanks to pages to the initial announcement (December tells me that I ought to be able to see seventy- the work done by Alan Dyer from 1978 to 1981, 1995, pp.38-43). Since then, another three and two of them, but some would be quite low in the users of the handbook have enjoyed access to half full-color pages have been devoted to in- southern sky and available for only a very short a number of lists arranged for easy use, season forming readers that for about ten dollars they part of the year. My colleagues in Edmonton by season, and containing throughout all of can be the proud owner of a reprint of the original would be able to see only 60% of the objects on them, objects that can be easily seen from the article and a laminated, note-paper-sized map the list. mid-northern latitudes. In 1979, Dyer organized of the sky with the CaIdwell objects labelled on Mr. Moore has chosen to list a relatively large the Messier list so that the objects would be it (February 1996, p.4; March 1996, p.47; April number of objects that are in the far southern arranged by season and by constellation—a 1996, p. 34; August 1996, p.100). sky. Six objects are within 20° of the South notable boon for the observer. In 1980 he com- Why the name “CaIdwell”? Mr. Moore in- Celestial Pole. One object, a planetary nebula piled a list of 110 of the finest non-Messier deep- formed us that Caldwell is a part of his surname whose size is listed as 0.6 arc-minutes, is lo- sky objects. This list, in which all the items were that he rarely uses and he chose it to avoid cated in the constellation Chamaeleon, only north of -26°, was organized in the same fashion confusing the “M” of Moore with that of Messier. nine degrees from the South Celestial Pole. as the updated Messier list. Both of these lists He said that the list would have 109 objects, not Such objects, and many others in the last half of have appeared in every handbook since 1981. 110, because “not many people accept M110, Moore’s list, are simply too far south to be seen If this were not enough, in 1981, Dyer com- one of the companions of M31, and still prefer to even by those who might occasionally vacation piled a further list, which he called a deep-sky call it NGC 205”. This, in spite of the fact that in the Caribbean and expect to complete the list challenge list, which comprised 110 objects, all M110 has been part of the Messier list in the at that time. One would, in fact, need to go much of them north of -35°, so that the entire list can Observer’s Handbook for the last seventeen further south in order to catch a glimpse of them, be seen from our latitude. Those of us within the issues, that is, since 1980. Also rather notable is and unless that person went well south of the society who had the fortune of obtaining this list, the statement that “except for the Astronomical equator, some of them would still be low in the (continued on page 11) League’s 400-object Herschel list, few [deep sky and within view for a only a brief time. R.A.S.C. BULLETIN S.R.A.C. - October & December/octobre & décembre 1996 - Page 1 Editor: Patrick M. Kelly, RR#2 Falmouth, A LA BULLETIN Nova Scotia, Canada B0P 1L0 AD S N OC A IÉ is a publication of the Royal Astronomical Society of E-mail Address: [email protected] C C I T T F D V V R É Canada and is distributed together with the society’s O A R FAX: (902) 423-6672 Y O N O T I V A Y Journal. It contains articles on current activities of the Phone: (902) 420-7604(w), (902) 798-3329(h) E A I Q C L R.A.S.C. and its centres across Canada, as well as E O Editorial Staff: Diane Brooks S D articles from members and non-members which are ’ L Rédacteur pour les Centres francais: A A S of general interest to members of the Society. Inquir- C T I Marc Gélinas, 11 Pierre-Ricard, N-D-lle-Perrôt, R M O ies about the Society should be directed to its national O N Québec, Canada J7V 8M6 N O office at 136 Dupont Street, Toronto, Ontario, Canada O M Printing: University of Toronto Press R I T E M5R 1V2 (416) 924-7973. S D A U L Printed on paper containing 50% pre-consumer C Web site: http://apwww.stmarys.ca/rasc/nat A A Y N O R A recycled paper and at least 5% post-consumer de- D E A H T Cover Picture: An aerial view of the University of inked fibre. Alberta, site of the 1996 General Assembly. January issue deadline is November 1st. spent the rest of his life working as a scientist. Harriot went on to make other astronomical Letters to the Editor Harriot’s first telescopes may have been brought discoveries though, other than describing them over from the Netherlands or made under his to his correspondents, he did not publish the Galileo Was #2 direction by his instrument maker, Christopher results. His most important contribution was Tooke. (As an interesting footnote, Harriot left discovering the rate of solar rotation as a result In the June Bulletin, it was stated that Galileo of a series of 199 observations made between made the first telescopic observations. Like the his “two perspective trunckes” to the “Wizard December 8th, 1610 and January 18th, 1613. myth that the great Italian made the first tel- Earl”—presumably the Earl of Northumberland.) Harriot also prepared a more detailed map of the escope, this claim too is incorrect. Galileo ap- On the recommendation of, and following Moon in 1611 (Figure 2) which shows craters, pears to have received word from the Nether- Harriot’s own first observations in June 1609, Sir though it is not clear how strongly he was lands about the newly discovered telescope William Lower and other of Harriot’s scientific influenced by reading Galileo’s Sidereus nuncius sometime in August 1609 and his first com- correspondents were attempting to use tel- in 1610 or whether it was due to an improved ments about observing the Moon date from escopes for astronomical purposes (this dem- telescope. In any case, this new map was still October, though it is very likely that he at- onstrates just how rapidly telescopes were be- inferior in detail to the map published by Galileo. tempted to discern the nature of the Moon’s coming available in England). By July, Lower Harriot’s manuscript maps are held by Lord surface somewhat earlier. Nonetheless, his first had made his own observations and returned a Egremont and Leconfield. For more information attempts at lunar observation were certainly not description to Harriot. Lower mentions the ob- consult: Terrie F. Bloom, J. for the History of made before late August, 1609. There exists a servation of earthshine, “luminous parts like Astronomy, 9 (1978), pp. 117-122; H.C. King, manuscript drawing by Thomas Harriot (1560- starres” (presumably peaks at the edge as the History of the Telescope (1955, 1979); E.G.R.