Photographs of Nebulæ and Clusters, Made with the Crossley Reflector

by James Edward Keeler

One of the most fruitful fields for this instrument is undoubtedly stellar spectroscopy. Little has been done in this field, as yet, with the Crossley reflector, but two spectrographs, with which systematic investigations will be made, have nearly been completed by the Observatory instrument-maker. One of these, constructed with the aid of a fund given by the late Miss C. W. Bruce, has a train of three 60° prisms and one 30° prism, and an aperture of two inches; the other, which has a single quartz prism, will, I have reason to expect, give measurable, though small, spectra of stars nearly at the limit of vision of the telescope.

The photogravure[12] of the Trifid nebula, which accompanies this article, was made from a photograph taken with the Crossley reflector on July 6, 1899, with an exposure of three hours. It was not selected as a specimen of the work of the instrument, for the negative was made in the early stages of the experiments that I have described, and the star images are not good, but rather on account of the interest of the subject. At the time the photogravures were ordered no large scale photograph of the Trifid nebula had, so far as I am aware, ever been published.[13] The remarkable branching structure of the nebula is fairly well shown in the photogravure, though less distinctly than in the transparency from which it was made. The enlargement, as compared with the original negative, is 2.9 diameters (1 mm = 13″). The fainter parts of the nebula would be shown more satisfactorily by a longer exposure.

List of Nebulæ and Clusters Photographed.

N.G.C. No.	α 1900.0			δ 1900.0		Remarks.
	h	m	s	°	′
185	0	33	25	+47	47.3	H II, 707
205	0	34	56	+41	8.2	H V, 18
221	0	37	15	+40	19.0	M 32
224	0	37	17	+40	43.4	Great nebula in Andromeda
247	0	42	3	-21	17.9	H V, 20
253	0	42	36	-25	50.6	H V, I
524	1	19	33	+ 9	1.0	H I, 151
598	1	28	12	+30	8.6	M 33
628	1	31	19	+15	16	M 74
650	1	36	0	+51	4.0	M 76
891	2	16	15	+41	53.6	H V, 19
1023	2	34	8	+38	38.0	H I, 156
1068	2	37	34	- 0	26.3	M 77
1084	2	41	5	- 8	0.0	H I, 64
...	3	41		+24		Pleiades in Taurus
1555	4	16	8	+19	17	T Tauri and Hind’s variable nebula
1931	5	24	48	+34	10.1	H I, 261
1952	5	28	30	+21	57	Crab nebula in Taurus
...	5	30		- 5		Great nebula in Orion
1977	5	30	27	- 4	54.2	H V, 30
2024	5	36	48	- 1	54.3	H V, 28
2068	5	41	37	+ 0	0.8	M 78
2239	6	25	37	+ 5	1.1	Cluster and nebula in Monoceros
2264	6	35		+10	0	Nebula near 15 Monocerotis
2287	6	42	43	-20	38.4	M 14
...	6	59	40	-10	18.2	New nebula in Monoceros
2359	7	12	54	-13	2.0	H V, 21
2366	7	18	18	+69	13.4	H III, 748
2371-2	7	19	6	+29	41.0	H II, 316-7
2403	7	27	9	+65	48.9	H V, 44
2437	7	35	24	-14	35.3	Cluster and nebula M 46
2632	8	34		+20		Præsepe cluster
2683	8	46	29	+33	47.8	H I, 200
2841	9	15	6	+51	24	H I, 205
2903-05	9	26	31	+21	57	H I, 56-57
3003	9	42	38	+33	52.8	H V, 26
3031	9	47	18	+69	32	M 81
3079	9	55	9	+56	10.1	H V, 47
3115	10	0	16	- 7	14.0	H I, 163
3169	10	9	4	+ 3	57.7	H I, 4
3184	10	12	15	+41	55.1	H I, 168
3198	10	13	42	+46	3.7	H I, 199
3226-7	10	17	59	+20	24.1	H II, 28-29
3242	10	19	29	-18	5	H IV, 27
...	10	21	7	+68	58	New nebula in Ursa Major (Coddington).
3556	11	5	40	+56	13.0	H V, 46
3587	11	9	0	+55	33.7	Owl nebula, M 97
3623	11	13	43	+13	38.4	M 65
3627	11	15	1	+13	32	M 66
3726	11	27	56	+47	35.8	H II, 730
4244	12	12	29	+38	22.0	H V, 41
4254	12	13	45	+14	59	M 99
4258	12	14	2	+47	51.6	H V, 43
4303	12	16	18	+ 5	1.7	M 61
4321	12	17	52	+16	22.7	M 100
4382	12	20	21	+18	44.7	M 85
4485-90	12	25	40	+42	15.3	H I, 197-198
4501	12	26	56	+14	58.5	M 88
4536	12	29	20	+ 2	44.2	H V, 2
4559	12	30	59	+28	30.6	H I, 92
4565	12	31	24	+26	32.2	H V, 24
4631	12	37	19	+33	5.9	H V, 42
4656-57	12	39	6	+32	42.8	H I, 176-7
4725	12	45	33	+26	3	H I, 84
4736	12	46	13	+41	39.5	M 94
4826	12	51	49	+22	13.9	M 64
5055	13	11	20	+42	33.6	M 63
5194-5	13	25	39	+47	42.6	M 51
5247	13	32	39	-17	22.4	H II, 297
5272	13	37	35	+28	53	M 3
5457-8	13	59	39	+54	50	M 101
5857-9	15	2	55	+19	58.9	H II, 751-2
5866	15	3	45	+56	9.0	H I, 215
5904	15	13	29	+ 2	27	M 5
6205	16	38	6	+36	39.0	M 13
6218	16	42	2	- 1	46.2	M 12
6412	17	32	41	+75	47.3	H VI, 41
6514	17	55	43	-23	2	Trifid nebula in Sagittarius
6523	17	57	43	-24	23	M 8
6543	17	58	35	+66	38	H IV, 37
6618	18	15	0	-16	13	M 17 Omega nebula
6656	18	30	17	-23	59.3	M 22
6705	18	45	42	- 6	23.3	M 11
6720	18	49	53	+32	54.0	M 57
6853	19	55	17	+22	27	Dumb-Bell nebula
6894	20	12	22	+30	15.5	H IV, 13
6946	20	32	48	+59	48.0	H IV, 76
6951	20	35	47	+65	45.4
6995	20	53	0	+30	49.8
7008	20	57	38	+54	9.5	H I, 192
7009	20	58	11	-11	48	H IV, 1
7023	21	0	30	+67	46.2	H IV, 74
7078	21	25	9	+11	43.7	M 15
7089	21	28	19	- 1	16.0	M 2
7099	21	34	42	-23	38.0	M 30
7217	22	3	24	+30	52.3	H II, 207
7331	22	32	30	+33	53.9	H I, 53
7448	22	55	7	+15	26.6	H II, 251
7479	22	59	56	+11	47.0	H I, 55
7537-41	23	9	38	+ 3	59.4	H II, 429-30
7662	23	21	5	+41	59.2	H IV, 18
7782	23	48	47	+ 7	24.8	H III, 233
7814	23	58	8	+15	34.5	H II, 240
7817	23	58	52	+20	11.6	H II, 227

Catalogue of New Nebulæ Discovered on the Negatives.

No.	α 1900.0			Precession.	δ 1900.0			Precession.	Description.
	h	m	s	s	°	′	″	″
1	0	0	27.4	+3.0732	+20	34	57	+20.048	vS eeF
2	0	32	7.7	3.2795	+47	55	29	19.855	eF N
3	0	32	8.1	3.2801	+48	1	22	19.855	F vbM E140°
4	0	32	9.3	3.2776	+47	37	24	19.855	eF bM
5	0	32	28.8	3.2799	+47	39	5	19.851	B vE70°
6	0	33	23.9	3.2674	+47	55	5	19.841	eF vS
7	0	35	43.1	3.3009	+47	46	18	19.810	eF vS
8	0	40	51.1	2.9793	-21	25	48	19.730	18 vS R
9	0	47	0.1	2.9804	-21	9	17	19.727	16 vS bM 3 sep. parts
10	0	41	16.2	2.9781	-21	29	43	19.723	18 vS R bM
11	0	41	16.7	2.9792	-21	15	2	19.723	18 vS R
12	0	41	29.7	2.9798	-21	3	8	19.719	18 vS bM E50°
13	0	42	4.4	2.9633	-26	0	7	19.711	17 vS R bsw
14	0	42	30.7	2.9780	-20	56	38	19.703	18 vS bM E115°
15	0	42	34.2	2.9620	-25	59	10	19.702	17 vS N E160°
16	0	42	37.6	2.9776	-20	58	28	19.701	14 S E stell N
17	0	42	39.7	2.9772	-21	1	54	19.701	17 vS Spiral bM
18	0	42	39.9	2.9774	-21	0	3	19.700	18 vS Ring?
19	0	42	40.5	2.9770	-21	3	55	19.700	15 S Spiral N bM
20	0	42	40.6	2.9762	-21	13	54	19.700	18 vS R
21	0	43	10.4	2.9603	-25	59	36	19.692	18 vS R bM
22	0	43	16.2	2.9730	-21	37	17	19.691	18 vS dif
23	0	43	27.1	2.9613	-25	40	21	19.688	17 vS R N
24	0	43	29.0	2.9593	-26	0	57	19.687	18 vS R gbM
25	0	44	10.8	2.9714	-21	30	29	19.676	18 vS R
26	0	44	26.6	2.9735	-20	58	35	19.672	17 vS R bM
27	1	18	30.9	3.1475	+ 9	27	25	18.887	F S N
28	1	18	53.5	3.1475	+ 9	24	28	18.875	F vbM Spiral?
29	1	19	11.3	3.1474	+ 9	21	53	18.867	F vbM Spiral?
30	1	19	30.7	3.1467	+ 9	14	18	18.857	F bM E
31	1	29	50.7	3.2101	+15	6	37	18.526	pF E45° bp
32	1	29	54.4	3.2161	+15	43	25	18.524	F R
33	1	30	20.9	3.2127	+15	17	38	18.509	vF L R
34	1	30	24.7	3.2132	+15	20	28	18.507	pF S vF extension 135°
35	1	30	35.9	3.2153	+15	32	2	18.501	S pB pmb M
36	1	30	54.7	3.2176	+15	43	1	18.491	vvF vS
37	1	31	5.0	3.2179	+15	43	38	18.485	F S E95°
38	1	31	15.9	3.2159	+15	30	44	18.478	pF S R
39	1	31	25.7	3.2187	+15	44	34	18.473	vF S R
40	1	31	44.8	3.2194	+15	46	49	18.462	F L R gbM
41	1	31	44.8	3.2126	+15	4	18	18.462	F L gbM R
42	1	32	5.9	3.2158	+15	20	54	18.450	S pB E135°
43	1	32	41.3	3.2171	+15	23	22	18.430	vF S E45°
44	1	32	48.8	3.2156	+15	12	27	18.424	vF pL
45	1	33	10.4	3.2168	+15	16	49	18.413	vF pL gbM
46	1	33	13.2	3.2166	+15	15	14	18.412	p B R gbM
47	2	14	10.2	3.7341	+41	50	8	16.715	pF E135°
48	2	14	26.6	3.7349	+41	49	1	16.701	pB N R
49	2	14	33.9	3.7307	+41	37	31	16.696	B N
50	2	14	36.7	3.7313	+41	38	24	16.694	F
51	2	14	55.0	3.7506	+42	24	20	16.677	eF vS bM E135°
52	2	15	6.2	3.7517	+42	25	6	16.668	F gbM E130° Spiral?
53	2	15	14.9	3.7493	+42	16	44	16.661	F pmbM
54	2	15	16.1	3.7484	+42	14	4	16.659	F B*f
55	2	15	38.4	3.7666	+42	55	0	16.641	eF vS R
56	2	15	43.8	3.7503	+42	13	58	16.637	S F R
57	2	15	56.5	3.7724	+43	5	24	16.626	F E170° bsf
58	2	16	1.0	3.7539	+42	20	55	16.623	B S vbM E150° bnp
59	2	16	6.4	3.7403	+41	44	51	16.619	S F R
60	2	16	9.7	3.7408	+41	45	26	16.616	F S pmbM
61	2	16	13.0	3.7613	+42	36	32	16.613	pB vbM E150° Spiral?
62	2	16	31.1	3.7640	+42	39	27	16.598	eeF E50°
63	2	16	34.5	3.7412	+41	42	6	16.595	pB pmbM
64	2	16	40.3	3.7620	+42	33	22	16.591	B S pbM
65	2	16	43.3	3.7403	+41	38	14	16.588	pB E0° pmbM
66	2	16	53.2	3.7625	+42	32	12	16.580	vB S mbM
67	2	16	57.8	3.7567	+42	16	48	16.576	F triN npN
68	2	17	13.8	+3.7403	+42	22	37	+16.563	pB bs B*p

No.	α 1900.0			Precession.	δ 1900.0			Precession.	Description.
	h	m	s	s	°	′	″	″
69	2	17	18.9	+3.7661	+42	36	12	+16.559	pS pB gbM E40°
70	2	17	28.5	3.7415	+41	33	3	16.551	pF S R
71	2	17	28.8	3.7560	+42	9	35	16.551	vF
72	2	17	33.2	3.7606	+42	20	17	16.547	F vS bnp
73	2	17	36.2	3.7789	+43	3	25	16.545	eeF S
74	2	17	37.2	3.7469	+41	45	2	16.544	F vL vmbM
75	2	17	41.8	3.7592	+42	15	8	16.540	S pB bs
76	2	17	43.3	3.7554	+42	5	21	16.539	F bsp
77	2	17	44.6	3.7441	+42	18	28	16.538	B S E90° bM
78	2	17	45.5	3.7425	+42	22	45	16.537	F L bM N B*np
79	2	17	50.8	3.7743	+42	50	20	16.533	pB gbM E135°
80	2	17	51.1	3.7484	+41	46	22	16.532	pB E135° gbM
81	2	18	0.2	3.7743	+42	48	30	16.525	vF pL gbM E50°
82	2	18	0.8	3.7502	+41	48	55	16.525	pF L
83	2	18	4.2	3.7603	+42	14	0	16.522	S B vbM
84	2	18	14.8	3.7579	+42	7	27	16.513	pB E150° Spiral
85	2	18	23.6	3.7792	+42	56	10	16.507	eeF pL E120°
86	2	18	26.7	3.7604	+42	10	8	16.503	vB E45°
87	2	18	30.7	3.7465	+41	34	13	16.499	F E150° bnf
88	2	18	33.5	3.7784	+42	52	19	16.498	B S gbM
89	2	18	34.0	3.7628	+42	14	44	16.497	vS vF bsp
90	2	18	37.4	3.7837	+43	4	26	16.495	S F bs
91	2	31	51.3	3.7209	+38	16	30	15.806	vF vS
92	2	33	53.9	3.7295	+38	19	27	15.694	F vS N
93	2	33	56.7	3.7461	+38	49	15	15.691	F S bn E0° long N
94	2	34	7.5	3.7405	+38	43	4	15.681	pF S i triN
95	2	34	9.2	3.7399	+38	43	10	15.680	pF vS
96	2	34	11.8	3.7259	+38	7	39	15.678	F L E40° Spiral on edge
97	2	34	44.2	3.7402	+38	38	27	15.648	eeeF doubtful
98	2	34	44.4	3.7488	+38	16	16	15.648	pB N E50° S pmbM
99	2	35	1.0	3.7469	+38	18	45	15.632	L F pmbM
100	2	36	32.9	3.7436	+38	30	26	15.548	S F E100°
101	2	36	53.3	3.0662	- 0	24	48	15.525	vS vF gbM
102	2	37	6.0	3.0728	- 0	2	43	15.518	vS F m E30°
103	2	38	44.2	3.0688	- 0	16	20	15.427	F S m E80°
104	2	41	11.6	2.9503	- 8	3	17	15.294	pB vS E135°
105	2	41	53.7	2.9564	- 7	38	9	15.254	vF vS mbM
106	2	42	18.9	2.9499	- 8	2	27	15.230	eeF S
107	4	35	22.9	3.0244	- 2	12	20	7.235	16 S E165° Dif bM
108	4	36	0.6	3.0307	- 1	54	37	7.183	18 vS R
109	4	36	3.6	3.0300	- 1	56	42	7.179	17 vS R stell
110	4	36	12.7	3.0337	- 1	46	19	7.167	16 vS nearly R bM
111	4	36	15.2	3.0238	- 2	13	38	7.164	18 vS R (Spiral?)
112	4	36	40.5	3.0251	- 2	9	53	7.129	18 vS R N
113	4	36	41.2	3.0293	- 1	58	23	7.128	18 vS E30° bn
114	4	37	2.4	3.0268	- 2	5	10	7.099	18 vS dif
115	4	37	26.8	3.0298	- 1	56	51	7.066	15 vS Spiral B N (stell)
116	5	24	48.1	3.9674	+34	6	28	+ 3.075	bright stell N on north side
117	7	14	0.7	6.4903	+69	39	20	- 6.362	17 vS bM
118	7	14	24.5	6.4656	+69	31	49	6.395	17 vS N Ring
119	7	14	37.5	6.4241	+69	18	15	6.413	17 R bM
120	7	15	45.6	6.4282	+69	21	35	6.507	17 vS
121	7	15	50.7	6.4875	+69	41	26	6.514	16 vS R
122	7	16	4.1	6.4719	+69	36	40	6.532	17 vS E125° D?
123	7	16	8.0	6.4219	+69	20	4	6.538	18 vS E70°
124	7	16	35.2	6.4099	+69	16	46	6.575	16 vS iF
125	7	16	48.0	6.4578	+69	33	16	6.593	17 vS R
126	7	17	9.1	6.4119	+69	18	25	6.622	18 vS R
127	7	17	38.5	6.4906	+69	45	29	6.662	17 vS bM R
128	7	17	45.3	6.4750	+69	40	36	6.672	17 vS R bM
129	7	17	49.6	3.7911	+29	41	49	6.677	18 vS F*inv dif
130	7	17	49.7	6.4843	+69	43	46	6.678	17 vS E135° bM N Spiral
131	7	18	11.1	6.4754	+69	41	28	6.707	16 vS dif 2 or 3 N
132	7	18	14.4	3.7838	+29	27	41	6.711	18 vS iF N
133	7	18	20.1	3.7840	+29	28	20	6.719	18 vS bM
134	7	18	21.1	3.7950	+29	51	18	6.721	18 vS bM
135	7	18	42.2	3.7832	+29	27	23	6.749	18 vS iF sc
136	7	18	51.0	6.6430	+69	38	32	6.763	17 vS E80° bM N Spiral on edge
137	7	18	56.5	3.7827	+29	27	7	6.769	19 vS
138	7	19	10.0	+3.7819	+29	26	7	- 6.788	18 vS R bM N Spiral?