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Roll Angle / Visibility Calculator

This table shows the default roll angle, and allowed range around this default value (min and max roll angles) for a target of given decimal RA and declination (J2000) for an entire year. All values are calulated at 12:00UT for each day. Only periods where the source is far enough away from the Sun to be observed are included in this table.

For each day, the distance from the Moon at 12:00UT is given, where this value is highlighted in red, the source is too close to the Moon to observe at that time of day.

Note this table does show Pole constraints. Please note all values are estimates and will need to be validated by the Swift planners.

Note: RA/Dec/Year not set, using defaults. Enter values in form below.

Valid Roll Angles for target RA=266, Dec=-29 in 2020
Day of Year	Sun RA (deg)	Sun Dec (deg)	Sun Distance (deg)	Moon Distance (deg)	Roll (deg)	Min Roll (deg)	Max Roll (deg)
Object in Sun Constraint
33	315.05	-17.03	46.36	134.28	86.22	73.10	99.35
34	316.07	-16.74	47.37	146.31	86.41	73.50	99.32
35	317.08	-16.45	48.38	158.44	86.59	73.88	99.30
36	318.09	-16.15	49.38	169.91	86.76	74.25	99.28
37	319.10	-15.85	50.39	171.27	86.93	74.60	99.26
38	320.10	-15.54	51.39	159.41	87.10	74.94	99.25
39	321.10	-15.23	52.40	145.63	87.26	75.27	99.25
40	322.10	-14.91	53.40	131.23	87.41	75.58	99.25
41	323.09	-14.59	54.41	116.51	87.56	75.88	99.25
42	324.08	-14.27	55.41	101.65	87.71	76.17	99.25
43	325.07	-13.94	56.42	86.80	87.86	76.45	99.26
44	326.05	-13.61	57.42	72.13	88.00	76.72	99.27
45	327.03	-13.27	58.42	57.73	88.13	76.98	99.29
46	328.01	-12.93	59.43	43.71	88.27	77.24	99.30
47	328.98	-12.59	60.43	30.14	88.40	77.48	99.32
48	329.95	-12.25	61.44	17.25	88.53	77.71	99.35
49	330.92	-11.90	62.44	7.13	88.66	77.94	99.37
50	331.89	-11.54	63.44	12.03	88.78	78.16	99.40
51	332.85	-11.19	64.45	23.66	88.90	78.37	99.43
52	333.81	-10.83	65.45	35.80	89.02	78.58	99.47
53	334.77	-10.47	66.45	47.94	89.14	78.78	99.51
54	335.72	-10.11	67.45	59.98	89.26	78.97	99.55
55	336.68	-9.74	68.45	71.92	89.37	79.16	99.59
56	337.63	-9.37	69.46	83.77	89.49	79.34	99.63
57	338.57	-9.00	70.46	95.54	89.60	79.52	99.68
58	339.52	-8.62	71.46	107.27	89.71	79.69	99.73
59	340.46	-8.25	72.46	119.00	89.82	79.85	99.78
60	341.40	-7.87	73.46	130.76	89.92	80.01	99.84
61	342.34	-7.49	74.46	142.60	90.03	80.17	99.89
62	343.28	-7.11	75.45	154.49	90.14	80.32	99.95
63	344.21	-6.73	76.45	166.17	90.24	80.47	100.01
64	345.14	-6.34	77.45	173.57	90.34	80.61	100.08
65	346.07	-5.96	78.45	164.83	90.45	80.75	100.14
66	347.00	-5.57	79.44	151.81	90.55	80.88	100.21
67	347.93	-5.18	80.44	137.87	90.65	81.02	100.28
68	348.85	-4.79	81.43	123.37	90.75	81.14	100.36
69	349.77	-4.40	82.43	108.47	90.85	81.27	100.43
70	350.70	-4.01	83.42	93.36	90.95	81.39	100.51
71	351.62	-3.62	84.42	78.20	91.05	81.50	100.59
72	352.54	-3.22	85.41	63.18	91.15	81.61	100.68
73	353.45	-2.83	86.40	48.47	91.24	81.72	100.76
74	354.37	-2.44	87.40	34.21	91.34	81.83	100.85
75	355.29	-2.04	88.39	20.61	91.44	81.94	100.94
76	356.20	-1.65	89.38	8.75	91.54	82.04	101.04
77	357.12	-1.25	90.37	9.48	91.63	82.13	101.13
78	358.03	-0.85	91.36	20.83	91.73	82.23	101.23
79	358.94	-0.46	92.35	32.95	91.83	82.32	101.34
80	359.85	-0.06	93.34	45.05	91.93	82.41	101.44
81	0.77	0.33	94.33	57.04	92.02	82.50	101.55
82	1.68	0.73	95.32	68.94	92.12	82.58	101.66
83	2.59	1.12	96.30	80.76	92.22	82.66	101.78
84	3.50	1.52	97.29	92.53	92.32	82.74	101.90
85	4.41	1.91	98.28	104.27	92.42	82.82	102.02
86	5.32	2.30	99.26	116.02	92.52	82.89	102.14
87	6.23	2.69	100.25	127.79	92.62	82.96	102.27
88	7.14	3.08	101.23	139.61	92.72	83.03	102.40
89	8.05	3.47	102.22	151.45	92.82	83.10	102.54
90	8.96	3.86	103.20	163.18	92.92	83.16	102.68
91	9.87	4.25	104.19	173.07	93.02	83.22	102.82
92	10.78	4.64	105.17	168.67	93.12	83.28	102.97
93	11.70	5.02	106.15	156.55	93.23	83.34	103.12
94	12.61	5.41	107.13	143.31	93.33	83.39	103.27
95	13.52	5.79	108.11	129.46	93.44	83.44	103.43
96	14.43	6.17	109.09	115.10	93.55	83.49	103.60
97	15.35	6.55	110.07	100.33	93.65	83.54	103.77
98	16.26	6.92	111.05	85.27	93.76	83.59	103.94
99	17.18	7.30	112.02	70.09	93.88	83.63	104.12
100	18.10	7.67	113.00	54.97	93.99	83.67	104.31
101	19.01	8.04	113.98	40.11	94.10	83.71	104.50
102	19.93	8.41	114.95	25.72	94.22	83.74	104.70
103	20.85	8.77	115.93	12.37	94.34	83.77	104.90
104	21.77	9.14	116.90	6.72	94.46	83.80	105.11
105	22.70	9.50	117.88	17.28	94.58	83.83	105.32
106	23.62	9.85	118.85	29.65	94.70	83.85	105.55
107	24.55	10.21	119.82	41.94	94.83	83.88	105.78
108	25.48	10.56	120.79	54.04	94.95	83.90	106.01
109	26.41	10.91	121.76	65.98	95.09	83.91	106.26
110	27.34	11.26	122.74	77.81	95.22	83.93	106.51
111	28.27	11.60	123.71	89.57	95.36	83.94	106.78
112	29.20	11.94	124.68	101.30	95.50	83.94	107.05
113	30.14	12.28	125.64	113.06	95.64	83.95	107.33
114	31.08	12.61	126.61	124.86	95.78	83.95	107.62
115	32.02	12.94	127.58	136.73	95.93	83.95	107.92
116	32.96	13.27	128.55	148.65	96.09	83.94	108.23
117	33.91	13.59	129.51	160.52	96.25	83.93	108.56
118	34.85	13.91	130.48	171.45	96.41	83.92	108.90
119	35.80	14.23	131.44	171.25	96.57	83.90	109.25
120	36.75	14.54	132.41	159.83	96.75	83.88	109.61
121	37.70	14.85	133.37	147.05	96.92	83.86	109.99
122	38.66	15.15	134.33	133.75	97.11	83.83	110.39
123	39.62	15.45	135.29	120.01	97.29	83.79	110.80
124	40.58	15.75	136.25	105.88	97.49	83.75	111.23
125	41.54	16.04	137.21	91.39	97.69	83.71	111.68
126	42.50	16.32	138.17	76.63	97.90	83.66	112.14
127	43.47	16.61	139.13	61.71	98.12	83.60	112.63
128	44.43	16.88	140.08	46.79	98.34	83.54	113.15
129	45.41	17.15	141.04	32.07	98.58	83.47	113.69
130	46.38	17.42	141.99	17.89	98.82	83.39	114.25
131	47.35	17.69	142.95	6.43	99.08	83.31	114.84
132	48.33	17.94	143.90	12.64	99.34	83.22	115.47
133	49.31	18.20	144.85	25.25	99.62	83.12	116.12
134	50.29	18.44	145.80	37.94	99.91	83.01	116.82
135	51.28	18.69	146.75	50.36	100.22	82.89	117.55
136	52.27	18.92	147.70	62.53	100.54	82.76	118.32
137	53.26	19.16	148.65	74.48	100.88	82.62	119.14
138	54.25	19.38	149.60	86.30	101.24	82.47	120.01
139	55.24	19.60	150.54	98.06	101.62	82.30	120.93
140	56.24	19.82	151.48	109.81	102.02	82.12	121.92
141	57.24	20.03	152.43	121.62	102.44	81.92	122.97
142	58.24	20.23	153.37	133.50	102.90	81.71	124.09
143	59.25	20.43	154.30	145.49	103.38	81.47	125.29
144	60.25	20.63	155.24	157.50	103.90	81.22	126.58
145	61.26	20.81	156.17	169.06	104.45	80.94	127.97
146	62.27	20.99	157.11	173.24	105.05	80.63	129.47
147	63.28	21.17	158.03	162.68	105.70	80.30	131.10
148	64.30	21.34	158.96	150.02	106.40	79.94	132.86
149	65.32	21.50	159.88	136.87	107.16	79.54	134.78
150	66.33	21.65	160.80	123.41	107.99	79.10	136.87
151	67.35	21.80	161.71	109.67	108.90	78.62	139.17
152	68.37	21.95	162.62	95.68	109.90	78.09	141.70
153	69.40	22.09	163.52	81.45	111.00	77.51	144.50
154	70.42	22.22	164.42	67.03	112.23	76.86	147.60
155	71.45	22.34	165.31	52.52	113.61	76.15	151.07
156	72.48	22.46	166.19	38.02	115.15	75.37	154.94
157	73.50	22.57	167.05	23.75	116.90	74.50	159.31
158	74.54	22.68	167.91	10.43	118.90	73.55	164.25
159	75.57	22.77	168.74	7.97	121.19	72.51	169.86
160	76.60	22.86	169.56	20.04	123.83	71.40	176.27
161	77.63	22.95	170.35	33.04	126.91	70.22	183.60
162	78.67	23.03	171.11	45.85	130.53	69.04	192.01
163	79.70	23.10	171.83	58.35	134.79	67.94	201.63
164	80.74	23.16	172.49	70.57	139.83	67.10	212.55
165	81.78	23.22	173.09	82.56	145.78	66.81	224.75
166	82.82	23.27	173.60	94.41	152.77	67.54	237.99
167	83.86	23.32	174.00	106.18	160.81	69.93	251.69
168	84.90	23.35	174.27	117.96	169.79	74.68	264.90
169	85.94	23.38	174.38	129.80	179.39	82.32	276.47
170	86.98	23.41	174.34	141.76	189.11	92.80	285.43
171	88.02	23.42	174.14	153.81	198.43	105.40	291.45
172	89.06	23.43	173.80	165.73	206.92	119.01	294.82
173	90.10	23.44	173.33	174.17	214.38	132.54	296.21
174	91.14	23.43	172.77	165.99	220.79	145.25	296.32
175	92.18	23.42	172.14	153.36	226.22	156.76	295.68
176	93.22	23.40	171.45	140.10	230.81	166.95	294.68
177	94.26	23.38	170.71	126.55	234.70	175.88	293.52
178	95.29	23.35	169.93	112.79	238.00	183.67	292.33
179	96.33	23.31	169.13	98.88	240.83	190.47	291.19
180	97.37	23.26	168.30	84.85	243.27	196.42	290.12
181	98.41	23.21	167.46	70.75	245.39	201.65	289.13
182	99.44	23.15	166.60	56.60	247.24	206.25	288.23
183	100.48	23.09	165.73	42.47	248.87	210.33	287.41
184	101.51	23.02	164.85	28.47	250.32	213.97	286.67
185	102.54	22.94	163.96	14.94	251.61	217.23	285.99
186	103.57	22.85	163.07	5.83	252.77	220.15	285.39
187	104.60	22.76	162.17	15.12	253.81	222.79	284.83
188	105.63	22.66	161.26	28.03	254.76	225.19	284.33
189	106.65	22.55	160.35	41.00	255.62	227.37	283.87
190	107.68	22.44	159.44	53.75	256.41	229.36	283.46
191	108.70	22.32	158.52	66.22	257.14	231.19	283.08
192	109.72	22.20	157.60	78.43	257.80	232.87	282.73
193	110.74	22.07	156.68	90.44	258.42	234.43	282.42
194	111.76	21.93	155.75	102.29	259.00	235.86	282.13
195	112.77	21.79	154.83	114.07	259.53	237.20	281.86
196	113.79	21.64	153.90	125.85	260.03	238.44	281.62
197	114.80	21.48	152.97	137.70	260.49	239.59	281.40
198	115.81	21.32	152.03	149.66	260.93	240.68	281.19
199	116.82	21.15	151.10	161.64	261.34	241.69	281.00
200	117.82	20.98	150.16	172.49	261.73	242.64	280.83
201	118.83	20.80	149.23	169.92	262.10	243.53	280.67
202	119.83	20.61	148.29	157.68	262.45	244.37	280.52
203	120.83	20.42	147.35	144.35	262.78	245.17	280.38
204	121.82	20.22	146.41	130.59	263.09	245.92	280.26
205	122.82	20.02	145.47	116.57	263.39	246.63	280.15
206	123.81	19.81	144.53	102.40	263.67	247.30	280.04
207	124.80	19.59	143.59	88.16	263.94	247.94	279.95
208	125.78	19.38	142.65	73.93	264.20	248.54	279.86
209	126.77	19.15	141.70	59.77	264.45	249.12	279.78
210	127.75	18.92	140.76	45.73	264.69	249.67	279.71
211	128.73	18.69	139.81	31.89	264.92	250.19	279.64
212	129.70	18.44	138.87	18.42	265.14	250.69	279.58
213	130.68	18.20	137.92	6.91	265.35	251.17	279.53
214	131.65	17.95	136.98	11.33	265.55	251.63	279.48
215	132.62	17.69	136.03	23.80	265.75	252.07	279.43
216	133.58	17.43	135.08	36.66	265.94	252.49	279.40
217	134.54	17.17	134.13	49.41	266.13	252.89	279.36
218	135.50	16.90	133.19	61.97	266.31	253.28	279.33
219	136.46	16.63	132.24	74.31	266.48	253.65	279.31
220	137.42	16.35	131.29	86.45	266.65	254.00	279.29
221	138.37	16.06	130.34	98.41	266.81	254.35	279.27
222	139.32	15.78	129.39	110.24	266.97	254.68	279.26
223	140.27	15.49	128.44	122.00	267.12	255.00	279.25
224	141.22	15.19	127.48	133.76	267.28	255.30	279.25
225	142.16	14.89	126.53	145.57	267.42	255.60	279.25
226	143.10	14.59	125.58	157.42	267.57	255.89	279.25
227	144.04	14.28	124.63	168.94	267.71	256.16	279.25
228	144.98	13.97	123.67	173.44	267.84	256.43	279.26
229	145.92	13.66	122.72	162.71	267.98	256.69	279.27
230	146.85	13.34	121.76	149.63	268.11	256.94	279.28
231	147.78	13.01	120.81	135.90	268.24	257.18	279.30
232	148.71	12.69	119.85	121.74	268.36	257.41	279.32
233	149.64	12.36	118.89	107.29	268.49	257.64	279.34
234	150.56	12.03	117.94	92.68	268.61	257.86	279.36
235	151.48	11.69	116.98	78.03	268.73	258.07	279.39
236	152.40	11.35	116.02	63.46	268.85	258.28	279.42
237	153.32	11.01	115.06	49.07	268.96	258.48	279.45
238	154.24	10.67	114.10	34.98	269.08	258.67	279.49
239	155.16	10.32	113.14	21.31	269.19	258.86	279.52
240	156.07	9.97	112.18	8.87	269.30	259.04	279.56
241	156.98	9.62	111.22	8.63	269.41	259.22	279.60
242	157.89	9.27	110.26	20.53	269.52	259.39	279.65
243	158.80	8.91	109.30	33.20	269.63	259.56	279.69
244	159.71	8.55	108.34	45.83	269.73	259.72	279.74
245	160.62	8.19	107.38	58.31	269.84	259.88	279.79
246	161.52	7.82	106.42	70.64	269.94	260.03	279.84
247	162.43	7.46	105.45	82.80	270.04	260.18	279.90
248	163.33	7.09	104.49	94.80	270.14	260.33	279.95
249	164.23	6.72	103.53	106.69	270.24	260.47	280.01
250	165.13	6.35	102.56	118.48	270.34	260.61	280.08
251	166.03	5.97	101.60	130.22	270.44	260.74	280.14
252	166.93	5.60	100.63	141.95	270.54	260.87	280.21
253	167.83	5.22	99.67	153.68	270.64	261.00	280.28
254	168.73	4.84	98.70	165.28	270.74	261.13	280.35
255	169.63	4.46	97.73	174.36	270.83	261.25	280.42
256	170.52	4.08	96.76	167.43	270.93	261.36	280.50
257	171.42	3.70	95.79	155.02	271.03	261.48	280.57
258	172.32	3.32	94.83	141.72	271.12	261.59	280.66
259	173.21	2.93	93.86	127.85	271.22	261.70	280.74
260	174.11	2.55	92.89	113.50	271.31	261.80	280.83
261	175.01	2.16	91.91	98.79	271.41	261.90	280.91
262	175.90	1.77	90.94	83.85	271.50	262.00	281.01
263	176.80	1.39	89.97	68.82	271.60	262.10	281.10
264	177.70	1.00	89.00	53.88	271.70	262.19	281.20
265	178.60	0.61	88.03	39.19	271.79	262.29	281.30
266	179.49	0.22	87.05	24.92	271.89	262.37	281.40
267	180.39	-0.17	86.08	11.56	271.98	262.46	281.51
268	181.29	-0.56	85.10	6.38	272.08	262.55	281.61
269	182.19	-0.95	84.13	17.63	272.18	262.63	281.73
270	183.09	-1.34	83.15	30.28	272.27	262.71	281.84
271	183.99	-1.73	82.18	42.85	272.37	262.78	281.96
272	184.89	-2.12	81.20	55.27	272.47	262.86	282.08
273	185.79	-2.50	80.22	67.52	272.57	262.93	282.21
274	186.69	-2.89	79.25	79.63	272.67	263.00	282.34
275	187.60	-3.28	78.27	91.61	272.77	263.06	282.47
276	188.50	-3.67	77.29	103.50	272.87	263.13	282.61
277	189.41	-4.05	76.31	115.31	272.97	263.19	282.75
278	190.32	-4.44	75.33	127.07	273.07	263.25	282.89
279	191.23	-4.82	74.35	138.80	273.17	263.31	283.04
280	192.14	-5.21	73.37	150.52	273.28	263.36	283.19
281	193.05	-5.59	72.39	162.15	273.38	263.42	283.35
282	193.97	-5.97	71.41	172.79	273.49	263.47	283.51
283	194.88	-6.35	70.43	171.02	273.60	263.52	283.68
284	195.80	-6.73	69.45	159.43	273.71	263.56	283.85
285	196.72	-7.11	68.46	146.73	273.82	263.61	284.03
286	197.64	-7.49	67.48	133.46	273.93	263.65	284.22
287	198.57	-7.86	66.50	119.67	274.05	263.69	284.41
288	199.50	-8.23	65.51	105.39	274.16	263.72	284.60
289	200.43	-8.60	64.53	90.69	274.28	263.76	284.80
290	201.36	-8.97	63.54	75.66	274.40	263.79	285.01
291	202.29	-9.34	62.55	60.48	274.52	263.82	285.23
292	203.23	-9.70	61.57	45.32	274.65	263.84	285.45
293	204.17	-10.06	60.58	30.39	274.77	263.87	285.68
294	205.11	-10.42	59.59	16.04	274.90	263.89	285.92
295	206.05	-10.78	58.60	5.21	275.04	263.91	286.17
296	207.00	-11.13	57.62	13.98	275.17	263.92	286.42
297	207.95	-11.49	56.63	26.91	275.31	263.93	286.68
298	208.90	-11.83	55.64	39.73	275.45	263.94	286.96
299	209.86	-12.18	54.65	52.28	275.59	263.95	287.24
300	210.82	-12.52	53.66	64.58	275.74	263.95	287.54
301	211.78	-12.86	52.67	76.69	275.90	263.95	287.84
302	212.74	-13.20	51.68	88.65	276.05	263.94	288.16
303	213.71	-13.53	50.69	100.51	276.21	263.93	288.49
304	214.68	-13.86	49.70	112.31	276.38	263.92	288.83
305	215.65	-14.18	48.71	124.08	276.55	263.90	289.19
306	216.63	-14.50	47.72	135.85	276.72	263.88	289.57
307	217.61	-14.82	46.72	147.62	276.91	263.86	289.95
Object in Sun Constraint

Science Operations Team Statistics

In the past 28 days, Swift has received 115 Target of Opportunity requests (4.1 per day), from 61 members of the community, for 96 different celestial objects. In that time Swift observed 72 targets in 103 separate observations on average per day. Swift was observing for 72% of the time, the rest of the time spent slewing or passing through the .