ASTRONOMISCHE NACHRICHTEN. Nr. 4154. Band 174. 2. Preliminary catalogue of Isaac Roberts’s collection of photographs of celestial objects. By Dorotha Isaac-Roberts. The Isaac Roberts collection of celestial photographs The number of the copies of the forthcoming paper comprises 2485 original negatives of stars, star-clusters, being very limited, the observatories and astronomers, official nebulae and other celestial objects together with many posi. or amateur, who are specially interested in photographic tives on glass and on paper, taken by the late Dr. Isaac astronomy will please send in their names to the address Roberts or, under his incessant supervision, by his assistant given below, early in 1907, in order that the various parts W. S. Franks, F. R. A. S., at Dr. Roberts’s Private Obser- of the complete catalogue may be sent to them in course vatory, Kennessee, Maghull, near Liverpool (1885-1 890) and, of time. from 1890 to 1904, at Starfield, Crowborough, Sussex. Positives- on-glass reproduced from the Isaac Roberts Of the above mentioned negatives, negatives will be lent for the purpose of micrometric mea- I) 1412 were taken with the zo-in Reflector (focal surements, if, application be made and provided that the length = 98.0 ins) and with an exposure of the plate of documents be returned after completion of the measurements. ninety minutes in general. In the preliminary catalogue given below, the numbers 2) 648 with the 5-in Cooke lens (f. 1. = 19.22 ins) of Dr. Dreyer’s New General Catalogue of Nebulae and which was mounted on the tube of the zo-in Reflector; or, Clusters of Stars and of Dr. Dreyer’s Index Catalogue have in some cases, with the 4-in Voigtlander (f. 1. = I 1.2 ins) been made use of; and, in order to save still more space, or with the 31/2-in Dallmeyer (f. I. = 9.56 ins). The ex- the NGC. numbers and the Ind. C. numbers for the con- posures with the Reflector and the Objective were simul- secutive hours of right ascension have been tabulated, the taneous. units of the first and second order forming the table, the With the exception of 140 negatives which are on units of the third and fourth orders are placed to the left plates 6 ins x 6 ins, the Isaac Roberts negatives measure of the line. 4 inches by 4 inches and are covered by a’ field of two de- The NGC. and Ind. C. numbers marked with a refer grees in diameter with the 20-in Reflector, 11 degrees in to published data found in: diameter with the Cooke lens, I I degrees in diameter, without too much distorsion, by the Dallrneyer, Voigtlander I. R. I 1 Isaac Roberts’s photographs of stars, star-clusters and Lerebours lenses. I. R. I1 J and nebulae, volumes I and I1 In the early days of Isaac Roberts’s astrophotographic .4. N. Astronomische Nachrichten career, many experimental plates were taken by him with Kn. Knowledge lenses ranging from three-eights to four inches in aperture. Obs. Observatory During the years 1885 and 1886, at Maghull, with R. I. A. Royal Irish Academy his zo-in Reflector and an exposure of the plate of 15 mi- M. N. Monthly Notices of the Royal Astr. Society nutes, he took Ap. J. Astrophysical Journal B. A. A. British Astronomical Association 3) 425 negatives, with the object of making a com- A. S. P. Astronomical Society of the Pacific plete chart of the heavens on a scale double of that of Bulletin de la Carte du Ciel. Argelander. The work was discontinued in 1887, in consequence placed after NGC. or Ind. C. numbers serve to in- of the International Astrophotographic Congress undertaking dicate that on the corresponding Isaac Roberts plates new to execute it. nebulae, not recorded in the catalogues, have been found. As soon as circumstances permit, a complete list of The present preliminary catalogue is published with Isaac Roberts’s tribute to astronomy will be published in the hope that the Isaac Roberts documents of celestial ob- accordance with the wishes and instructions of the deceased. jects may be of immediate service to astronomy. 2 19 4154 20 Preliminary catalogue of Isaac Roberts's collection of photographs of celestial objects. RA. oh. NGC. o 12i 23~29~ 56, 681 83 NGC.205, 221, 224: I.R.131~I.R.1163,M.N.49.65,Obs.12.94. I I0i 29~367 461 47, 85 - NGC. 246: I.R.11 123. - NGC. 253: Kn. 1900 p. 132. - 2 05-1 21', 24', 251 46', 471 53'~ 781 81' NGC. 281 : 1. R.11 147. - Ind. C. 59: I. R.133, I. R. I1 159~ 1nd.C. o 11, 59' Kn. 1898 p. 106 Nebulae on I. R.pl. 1728.(1890 Jan. 17) Nova Andromedae M. N. 51.116 Nova Tycho M. N. 50.359 Variable nebula (Barnard) Ceti Herschel's nebulous regions No. I, 2, 3, 4, 5, A. N. 3836, Ap. J. 17.72 6, 8, 9' 10 Star magnitudes. Pickering's Chart No. I M. N. 45. I 24 (Prof. E. C. Pickering) (80) Sappho M. N. 47.265 Comet Holmes 1892 I11 Chart plai 5: Decl. 76", 74" M. N. 49 p. 13 p. I 18, Bulletin de la Carte du Ciel I p. I 5 I RA. I~. NGC. 3 NGC. 393 = I. R. 2494, on pl. a new spiral 63" p. 14' 56" s. 4 of H.I. 54. - NGC. 581: I. R.1 35, M. N. 53.331. - NGC. 5 598: I.R.11 65, M. N. 56.70, Kn. 1896 p. 158, Proc.R.1.A. 6 25 section A (Dr. J. L.E.Dreyer). - NGC. 628: I.R.11 67, 6 M. N. 54.438, Kn. 1897 p. 53. - NGC. 650, 651 : I. R.1 37. 7 - NGC. 654, 663: I.R. I1 29. - NGC. 672 = I. R. 2495, 1nd.C. I on pl. new nebulae, Obs. 20.245, A. N. 3429 see above M. N. 53.65 Chart pl. see above RA. zh. NGC. 8 21i 69'1 84', 91'1 94, 95 NGC. 869, 884: I. R. 139, M. N. 50.315. - NGC. 891 l): I. R.1 9 36, 49, 57, 72 41. - NGC. 1023 = I.R. 1776, a new spiral nebula on pl., I0 12, 22, 23*', 27, 39*, 52, 60, 68', 84 M. N. 54.371. - NGC. 1039: I.R.1 43, M.N.53.357. - I1 56, 70 NGC. 1068: I. R. I 45, M. N. 53.331. - 1nd.C. 239, new spiral Ind.C. 2 3 9" Herschel's nebulous region No. 12 see above Chart pl. Decl. 86", 84", 82O, 80"' 78", 76O, 74", 1z0, 70° see above KA. 3h. NGC. 12 451 53 NGC. 1499: I. R. I1 149~Kn. 1899 p. 39 I3 00, 42 I4 441 53, 9'1 99' 1nd.C. 3 48 Nova Persei Yleiades and region around the Pleiades I. R.1 47, I.R.11 161, Obs. 12.94, M.N. 47 p.24 p.90, 49 p.7 p. 120, 58.392 Coniet Wolf 189 I I1 Comet 1902 I11 Kn. 1903 p. 9 Neptune and its satellite M. N. 5' P. 439 Region of comet 1892 I1 photographed on Nov. 18, 1892, I. R. plate No. 1800 68", 66" see above ') NGC. 891 (H.V 19) = I. R. 1765, 2928, see M. N. vol. 65 plate 7, photographed under Dr. Isaac Roberts's supervision and direction at his private observatory Starfield 011 Dec. 21, 1891, and Jan. 14, 1901. 21 41.54 22 RA. 4h. NGC. 15 NGC. 1528: I. R.11 31. - NGC. 1579 = I. R. 1810, new ne- 16 bula on pl., A.N. 3429, Obs. 20.244. - NGC. 1618 = I.R. 2585, 5 or 6 nebulae in radius of I". - NGC. 1665 = I. R. 312 I, ten new nebulae on pl., M. N. 43.301 Herschel's nebulous regions No. I 4, I 5, I 6 77, 18, '9 see above Espin's object in Perseus B. A. A, vol. 8.279 Neptune and its satellite see above Cluster Hyades. a Tami Chart pl. Decl. 86", 84", 82", go0, 78", 76", 74", 72" lo", 68", 66", 64", 62", 60" see above RA. 5h. NGC. 17 78, 88' NGC. 1788: Kn. 1901 p. 180. - NGC. 1952: 1.R.I 53, I.R. Ia 88 I1 169, Kn. 1896 p. 58. - NGC. 1960: 1.R. 151, M.N. I9 04, 07, 08, O9, 24, 27, 3'1 52*, 60', 16', 53.444. - NGC. 1976: I.R. 155, 57, 59, I.R.11 165, Kn. 19 82'1 90, 99 1897 p.100, M. N. 47.89, 49.295. - NGC. 1982: M. N. 49.295. 20 24, 68', 11*, 99' - NGC. 2068, 2071: Kn. 1895 p. 253, M.N.54.437. - NGC. 21 29, 427 58' 2099: I. R. 161, Kn. 1897 p. 10, M.N. 53.444. - NGC. 2158: 1nd.C. 4 05*1 I0, 17, '9, 231 24~251 261 27~28, Kn. 1901 p. 11. - Ind. C. 405: Kn. 1903 p. 81 4 301 31, 32, 341 351 39 Nova Aurigae (1892 Febr. I) I. R. I 49, M. N. 52.371, 53.123 Herschel's nebulous regions No. 20, 2 I , 2 2 23~240 25, 27 see above Stars in Orion M. N. 50.326 Star magnitudes. Pickering's Chart No. z see above a Aurigae. a Orionis Chart pl. Decl. 88", 86", 84", 8z0, goo, 78", 76", 74" 72", loo, 68", 66", 64", 62" see above LA.