Swift Trigger: 453788;

Presumed name: GRB 110521A

BAT	08^h 00^m 34.56^s, +45° 47′ 52.8″
position:	(120.144, 45.798 ± 180″)
XRT	08^h 00^m 31.85^s, +45° 49′ 35.4″
position:	(120.1327, 45.8265 ± 2.3″)
UVOT	No position available.
Galactic N_HI:	0.00×10⁰ cm^-2
Galactic E(B-V):	0.088 mag

Best RA:	08^h 00^m 31.85^s	= 120.1327 d
Best Dec:	+45° 49′ 35.4″	= 45.8265 d

Gal Lat:
Gal Long:

Sun angle:	56.49°, -4.2 hr East of Sun

¹Sper #2 auto processing.

Stars within 3.33 of XRT position

	RA*	Dec*		Catalogue
16.4	120.1264	45.8254	I=19.6, R=21.1, g=22.8, u=24.1, z=18.8	SDSS
23.4	120.1389	45.8216	I=18.5, R2=20.5	USNO-B1
23.6	120.1389	45.8216	I=19.3, R=20.6, g=22.1, u=25.3, z=18.6	SDSS
25.3	120.1307	45.8334	I=20.8, R=21.1, g=21.5, u=22.5, z=20.8	SDSS
26.6	120.1423	45.8296	I=24.7, R=25.1, g=24.2, u=24.3, z=20.0	SDSS
38.5	120.1250	45.8358	h=12.8, j=13.3, k=12.7	2MASS
38.5	120.1250	45.8358	I=14.3, R=14.6, g=15.3, u=16.9, z=14.2	SDSS
38.7	120.1250	45.8358	B1=15.4, B2=15.5, I=14.0, R1=14.0, R2=14.3	USNO-B1
38.8	120.1468	45.8221	I=21.0, R=22.2, g=24.0, u=25.7, z=20.2	SDSS
41.7	120.1240	45.8166	B1=20.8, B2=20.9, I=17.2, R1=18.2, R2=18.1	USNO-B1
41.9	120.1240	45.8166	h=15.2, j=16.0, k=14.9	2MASS
42.0	120.1239	45.8166	I=17.7, R=18.7, g=20.3, u=22.9, z=17.2	SDSS
49.0	120.1381	45.8134	I=25.1, R=25.1, g=26.0, u=22.2, z=23.4	SDSS
53.4	120.1274	45.8409	I=18.2, R=19.0, g=20.7, u=23.8, z=17.7	SDSS
53.5	120.1276	45.8409	h=15.7, j=16.4, k=15.5	2MASS
53.7	120.1274	45.8410	B1=20.8, B2=21.3, I=17.4, R1=18.8, R2=18.8	USNO-B1
57.8	120.1536	45.8198	I=18.0, R2=19.4	USNO-B1
57.8	120.1536	45.8197	I=18.6, R=20.0, g=21.5, u=23.7, z=17.9	SDSS
58.0	120.1537	45.8197	h=15.8, j=16.4, k=15.9	2MASS
59.3	120.1239	45.8418	I=20.5, R=21.8, g=23.4, u=25.3, z=19.8	SDSS
59.3	120.1445	45.8408	I=21.7, R=22.6, g=24.1, u=23.7, z=21.5	SDSS
66.8	120.1070	45.8315	I=21.1, R=21.8, g=23.7, u=24.7, z=20.6	SDSS
72.0	120.1513	45.8113	R1=20.1, R2=20.6	USNO-B1
75.5	120.1468	45.8079	I=22.6, R=22.6, g=23.4, u=24.3, z=22.7	SDSS
80.0	120.1403	45.8049	I=21.7, R=22.2, g=23.8, u=25.1, z=21.4	SDSS
85.8	120.1639	45.8167	B1=16.1, B2=16.2, I=14.8, R1=14.8, R2=15.2	USNO-B1
85.9	120.1639	45.8166	I=15.3, R=15.5, g=16.1, u=17.6, z=15.2	SDSS
85.9	120.1639	45.8167	h=13.9, j=14.3, k=13.9	2MASS
91.6	120.1004	45.8383	I=24.8, R=22.5, g=25.3, u=24.6, z=22.3	SDSS
91.8	120.1504	45.8488	I=22.1, R=22.5, g=23.1, u=25.3, z=21.0	SDSS
92.9	120.1392	45.8011	B1=17.2, B2=17.5, I=16.2, R1=16.5, R2=16.5	USNO-B1
93.1	120.1393	45.8010	h=15.7, j=15.9, k=15.8	2MASS
93.2	120.1393	45.8010	I=16.8, R=17.0, g=17.5, u=18.8, z=16.8	SDSS
97.2	120.1235	45.8003	I=21.0, R=21.2, g=21.9, u=22.8, z=21.1	SDSS
98.5	120.0984	45.8398	I=21.3, R=22.6, g=23.5, u=23.9, z=21.2	SDSS
99.3	120.1707	45.8343	B1=20.7, B2=20.7, I=19.0, R2=19.8	USNO-B1
99.4	120.1718	45.8311	B2=20.4, R1=20.1, R2=19.4	USNO-B1
99.5	120.0936	45.8310	I=24.7, R=22.6, g=25.0, u=23.9, z=21.3	SDSS
99.6	120.1045	45.8070	B1=20.5, B2=21.6	USNO-B1
103.8	120.1355	45.8553	I=20.0, R=21.3, g=22.9, u=25.1, z=19.3	SDSS
105.5	120.1319	45.7972	I=24.6, R=24.5, g=23.0, u=24.0, z=23.8	SDSS
110.4	120.1653	45.8471	h=15.8, j=16.5, k=15.8	2MASS
110.8	120.1654	45.8472	I=18.6, R=19.7, g=21.3, u=23.4, z=18.0	SDSS
111.1	120.1300	45.8573	I=21.4, R=21.7, g=22.1, u=22.8, z=21.4	SDSS
111.1	120.1655	45.8473	B2=20.8, I=17.9, R1=19.4, R2=19.3	USNO-B1
111.7	120.1523	45.7986	I=22.1, R=25.0, g=24.6, u=25.1, z=21.6	SDSS
113.5	120.1491	45.7971	B1=20.6, B2=21.2, R1=19.6, R2=19.7	USNO-B1
115.5	120.1754	45.8145	B1=18.7, B2=18.2, I=15.2, R2=16.2	USNO-B1
115.7	120.1755	45.8145	I=15.7, R=16.6, g=18.2, u=20.9, z=15.2	SDSS
115.8	120.1755	45.8145	h=13.4, j=14.0, k=13.1	2MASS
116.9	120.0913	45.8414	I=19.6, R=20.8, g=22.2, u=25.3, z=18.9	SDSS
117.4	120.1601	45.8530	I=18.1, R=18.3, g=18.8, u=20.1, z=18.0	SDSS
117.6	120.1600	45.8530	B1=18.9, B2=18.6, I=18.1, R1=18.4, R2=17.9	USNO-B1
118.3	120.1714	45.8078	B1=17.6, B2=17.7, I=16.4, R1=16.6, R2=16.6	USNO-B1
118.5	120.1714	45.8077	I=16.8, R=17.1, g=17.7, u=19.5, z=16.7	SDSS
118.8	120.1716	45.8077	h=15.6, j=15.8, k=15.1	2MASS
120.4	120.1049	45.7992	I=18.9, R1=19.6, R2=19.6	USNO-B1
122.1	120.0849	45.8201	I=20.1, R=21.0, g=22.7, u=24.0, z=19.9	SDSS
122.9	120.0912	45.8084	I=23.7, R=25.6, g=25.5, u=25.4, z=20.6	SDSS
123.9	120.1430	45.8602	I=21.6, R=21.9, g=22.4, u=25.1, z=21.2	SDSS
129.0	120.1624	45.8557	I=19.7, R=20.2, g=21.6, u=23.8, z=19.4	SDSS
129.2	120.1623	45.8559	B2=21.5, R2=19.9	USNO-B1
131.6	120.1807	45.8117	I=18.7, R=20.2, g=21.3, u=23.1, z=26.6	SDSS
132.8	120.0902	45.8045	I=22.0, R=22.9, g=24.1, u=24.0, z=22.4	SDSS
133.2	120.1803	45.8102	B1=17.1, B2=17.2, I=15.3, R1=15.8, R2=16.1	USNO-B1
133.3	120.1803	45.8101	I=16.3, R=16.6, g=17.2, u=18.7, z=16.1	SDSS
133.4	120.1804	45.8101	h=14.8, j=15.2, k=14.7	2MASS
134.5	120.1241	45.8634	h=13.4, j=14.0, k=13.2	2MASS
134.5	120.1863	45.8276	I=20.0, R=20.9, g=22.9, u=24.5, z=19.4	SDSS
134.5	120.1241	45.8634	I=15.3, R=15.9, g=16.7, u=18.8, z=15.1	SDSS
134.9	120.1240	45.8635	B1=16.6, B2=16.8, I=14.8, R1=15.0, R2=15.3	USNO-B1
135.3	120.0978	45.7979	B2=20.9, R2=20.0	USNO-B1
136.0	120.1630	45.7952	B1=19.7, B2=19.7, I=18.9, R1=19.0, R2=19.0	USNO-B1
136.2	120.1631	45.7951	I=18.8, R=19.0, g=19.6, u=20.9, z=18.7	SDSS
139.1	120.1850	45.8137	B1=16.5, B2=16.6, I=14.4, R1=14.6, R2=15.1	USNO-B1
139.1	120.0794	45.8159	I=24.7, R=22.4, g=24.7, u=24.4, z=23.4	SDSS
139.2	120.1850	45.8136	I=14.9, R=15.4, g=16.5, u=18.8, z=14.7	SDSS
139.2	120.1851	45.8137	h=12.9, j=13.5, k=12.8	2MASS
139.6	120.1123	45.7904	I=23.2, R=22.8, g=25.7, u=25.2, z=22.1	SDSS
141.9	120.0768	45.8325	I=22.0, R=24.3, g=24.1, u=24.9, z=21.5	SDSS
146.3	120.1144	45.8651	I=18.0, R=18.3, g=19.4, u=21.8, z=17.7	SDSS
146.4	120.0884	45.8530	I=21.1, R=22.1, g=23.7, u=26.6, z=20.3	SDSS
146.5	120.1144	45.8651	h=16.0, j=16.6, k=15.7	2MASS
146.9	120.0741	45.8272	I=24.3, R=25.3, g=23.0, u=25.4, z=22.5	SDSS
147.2	120.1624	45.7912	B1=20.8, B2=21.2, R2=20.2	USNO-B1
147.7	120.1624	45.7911	I=20.0, R=20.2, g=20.6, u=21.9, z=19.9	SDSS
148.8	120.1426	45.7857	I=19.0, R=20.1, g=21.6, u=24.7, z=18.5	SDSS
150.0	120.1635	45.8622	B1=20.7, B2=21.0, I=18.8, R2=19.6	USNO-B1
150.3	120.0995	45.7918	I=21.5, R=23.3, g=23.9, u=25.2, z=21.0	SDSS
150.5	120.1892	45.8124	I=24.1, R=24.1, g=23.0, u=25.1, z=22.1	SDSS
150.9	120.1787	45.8536	I=22.3, R=23.9, g=24.9, u=23.9, z=21.6	SDSS
151.8	120.1194	45.7854	I=24.0, R=24.0, g=23.2, u=25.7, z=21.9	SDSS
152.0	120.1906	45.8141	I=23.8, R=25.6, g=23.0, u=25.0, z=22.8	SDSS
152.7	120.0753	45.8124	h=14.2, j=14.8, k=13.9	2MASS
152.8	120.0752	45.8125	B1=20.1, B2=19.6, I=16.1, R1=17.3, R2=17.4	USNO-B1
152.8	120.0752	45.8124	I=16.8, R=18.0, g=19.6, u=22.2, z=16.2	SDSS
153.2	120.1293	45.8690	I=23.9, R=22.8, g=25.9, u=24.0, z=23.2	SDSS
155.4	120.1680	45.8620	I=20.4, R=20.7, g=21.2, u=22.3, z=20.2	SDSS
155.7	120.0725	45.8370	I=20.8, R=22.0, g=23.9, u=25.0, z=20.2	SDSS
156.0	120.1680	45.8622	B1=20.9, B2=21.4, R2=20.5	USNO-B1
156.6	120.1947	45.8215	I=20.6, R=20.9, g=21.6, u=23.1, z=20.3	SDSS
156.8	120.0716	45.8174	I=22.8, R=22.6, g=24.5, u=24.1, z=22.1	SDSS
157.2	120.1632	45.7883	I=24.8, R=25.2, g=25.9, u=24.1, z=20.5	SDSS
157.6	120.1614	45.8654	B1=21.0, I=18.9, R2=20.3	USNO-B1
157.6	120.1609	45.8656	I=19.5, R=20.5, g=22.1, u=24.1, z=18.9	SDSS
157.9	120.1955	45.8234	I=19.6, R=20.0, g=21.0, u=23.1, z=19.3	SDSS
157.9	120.1955	45.8235	B1=21.0, B2=21.1, I=18.9, R1=19.6, R2=19.7	USNO-B1
158.1	120.0939	45.7919	B1=20.6, R1=20.0	USNO-B1
159.6	120.0852	45.8560	h=13.8, j=14.5, k=13.6	2MASS
159.7	120.0851	45.8560	I=16.5, R=17.7, g=19.3, u=22.1, z=15.9	SDSS
159.8	120.0690	45.8270	I=20.3, R=22.1, g=23.7, u=26.3, z=19.4	SDSS
160.3	120.0689	45.8292	I=24.3, R=25.5, g=23.4, u=24.9, z=22.5	SDSS
161.5	120.0793	45.8015	B2=21.3, R2=20.0	USNO-B1
162.5	120.1102	45.7842	I=21.5, R=22.4, g=23.3, u=24.9, z=21.5	SDSS
165.4	120.1422	45.7810	B1=16.2, B2=16.2, I=14.5, R1=14.5, R2=14.8	USNO-B1
165.6	120.1422	45.7810	h=13.0, j=13.5, k=12.9	2MASS
165.6	120.1422	45.7810	I=14.8, R=15.2, g=16.2, u=18.7, z=14.6	SDSS
165.7	120.1739	45.7905	I=25.5, R=26.1, g=23.4, u=25.0, z=22.4	SDSS
166.1	120.1894	45.8026	B1=19.5, B2=19.5, I=15.9, R1=17.2, R2=17.3	USNO-B1
166.2	120.1894	45.8026	h=14.1, j=14.8, k=13.8	2MASS
166.2	120.1894	45.8026	I=16.6, R=17.8, g=19.3, u=22.0, z=16.0	SDSS
166.3	120.1989	45.8242	h=15.4, j=15.9, k=15.0	2MASS
166.4	120.1989	45.8242	I=18.2, R=19.7, g=21.2, u=23.8, z=17.4	SDSS
166.6	120.1256	45.8725	I=22.1, R=23.2, g=24.6, u=25.8, z=21.9	SDSS
167.6	120.0911	45.7901	B1=17.0, B2=17.2, I=17.5, R1=16.8, R2=16.9	USNO-B1
167.8	120.0911	45.7900	I=17.4, R=17.3, g=17.4, u=18.8, z=17.4	SDSS
167.8	120.0911	45.7900	h=16.6, j=16.8, k=15.7	2MASS
169.6	120.1227	45.7799	B1=20.7, B2=20.4, I=18.5, R1=19.3, R2=18.8	USNO-B1
169.7	120.1227	45.7799	h=16.5, j=17.4, k=15.6	2MASS
170.0	120.1580	45.7827	h=16.6, j=16.9, k=16.0	2MASS
170.2	120.1580	45.7826	B1=18.9, B2=18.4, I=17.7, R1=17.8, R2=17.8	USNO-B1
170.5	120.1580	45.7826	I=17.8, R=18.1, g=18.8, u=20.5, z=17.8	SDSS
171.1	120.0699	45.8451	I=20.6, R=21.4, g=22.7, u=23.8, z=19.9	SDSS
171.5	120.2004	45.8198	I=20.2, R=21.0, g=22.5, u=23.5, z=19.7	SDSS
172.1	120.1854	45.7959	I=23.2, R=25.0, g=25.4, u=24.5, z=20.6	SDSS
172.4	120.1559	45.7814	I=20.9, R=21.9, g=23.4, u=25.2, z=20.4	SDSS
175.2	120.1957	45.8056	I=21.9, R=22.1, g=22.8, u=23.8, z=21.6	SDSS
175.7	120.0873	45.7893	I=21.4, R=22.2, g=23.8, u=23.9, z=21.1	SDSS
176.3	120.1419	45.7779	I=21.3, R=21.7, g=22.5, u=23.3, z=21.1	SDSS
177.9	120.0831	45.8618	h=16.6, j=17.0, k=15.8	2MASS
177.9	120.1965	45.8482	I=20.7, R=22.7, g=24.9, u=24.2, z=19.5	SDSS
178.0	120.0830	45.8618	I=19.8, R=21.2, g=22.8, u=23.9, z=19.1	SDSS
179.0	120.0619	45.8206	B1=20.4, R2=20.5	USNO-B1
179.2	120.2038	45.8220	I=24.1, R=24.9, g=22.9, u=24.3, z=21.9	SDSS
179.6	120.1450	45.7773	h=14.7, j=15.3, k=14.5	2MASS
179.6	120.1450	45.7773	I=16.6, R=17.1, g=18.1, u=20.6, z=16.4	SDSS
180.9	120.0812	45.8617	I=21.3, R=22.4, g=24.1, u=24.2, z=20.9	SDSS
181.4	120.1189	45.8760	I=20.4, R=21.0, g=22.3, u=23.8, z=20.1	SDSS
181.6	120.1341	45.8769	h=14.5, j=15.2, k=14.4	2MASS
181.7	120.1341	45.8770	I=16.6, R=17.1, g=18.3, u=20.8, z=16.4	SDSS
182.0	120.1341	45.8770	B1=18.2, B2=18.1, I=16.1, R1=16.3, R2=16.5	USNO-B1
182.7	120.0616	45.8155	B2=21.6, R2=20.0	USNO-B1
184.1	120.2052	45.8345	I=20.0, R=21.2, g=22.6, u=24.9, z=19.3	SDSS
185.4	120.1682	45.8717	I=22.5, R=22.7, g=23.4, u=24.8, z=21.9	SDSS
185.7	120.1293	45.7750	B1=19.3, B2=19.0, I=17.1, R1=17.3, R2=17.4	USNO-B1
185.8	120.0713	45.8554	I=18.9, R2=19.8	USNO-B1
185.8	120.0595	45.8346	B1=20.9, R2=20.2	USNO-B1
185.9	120.0595	45.8344	I=20.2, R=20.8, g=22.0, u=24.3, z=19.8	SDSS
185.9	120.1293	45.7749	h=15.3, j=16.0, k=15.1	2MASS
186.0	120.1293	45.7749	I=17.4, R=17.8, g=19.0, u=21.5, z=17.1	SDSS
187.2	120.1338	45.7745	I=21.3, R=22.2, g=24.1, u=23.7, z=20.8	SDSS
187.3	120.1276	45.8784	I=21.4, R=22.0, g=23.4, u=25.0, z=20.6	SDSS
188.6	120.1010	45.7790	I=21.4, R=21.8, g=22.4, u=23.0, z=21.2	SDSS
188.9	120.1631	45.7785	B1=19.2, B2=19.8, I=18.6, R1=18.4, R2=18.6	USNO-B1
189.3	120.1631	45.7784	I=18.7, R=18.9, g=19.2, u=20.8, z=18.7	SDSS
189.9	120.1806	45.8674	I=22.2, R=23.7, g=24.5, u=25.0, z=22.2	SDSS
190.4	120.0829	45.8664	I=25.1, R=24.9, g=25.0, u=23.9, z=20.7	SDSS
190.9	120.1063	45.7768	B1=16.2, B2=16.1, I=14.9, R1=14.9, R2=15.2	USNO-B1
191.1	120.1064	45.7767	h=13.9, j=14.3, k=13.8	2MASS
191.2	120.1064	45.7767	I=15.3, R=15.6, g=16.2, u=17.7, z=15.2	SDSS
192.1	120.2083	45.8351	I=19.4, R=20.6, g=22.3, u=25.7, z=18.9	SDSS
192.2	120.2083	45.8352	I=18.9, R1=19.8, R2=20.1	USNO-B1
192.2	120.1451	45.7738	I=22.1, R=24.2, g=24.2, u=25.2, z=23.4	SDSS
192.3	120.1526	45.7749	I=18.6, R=20.0, g=21.5, u=23.1, z=17.9	SDSS
192.4	120.1527	45.7749	h=15.9, j=16.5, k=15.9	2MASS
193.4	120.0923	45.8722	I=20.5, R=21.0, g=22.3, u=24.5, z=20.4	SDSS
193.5	120.1156	45.8789	I=24.0, R=25.3, g=23.1, u=24.3, z=23.6	SDSS
195.1	120.0550	45.8293	I=18.8, R1=20.0, R2=20.4	USNO-B1
195.2	120.0550	45.8292	I=19.8, R=20.9, g=22.4, u=24.7, z=19.1	SDSS
198.1	120.0555	45.8149	I=25.2, R=25.9, g=22.9, u=23.4, z=22.2	SDSS
198.4	120.1136	45.7730	I=23.4, R=22.7, g=23.3, u=25.4, z=22.8	SDSS
198.7	120.0573	45.8434	B2=21.8, R2=20.7	USNO-B1

Queried USNO-B1, SDSS, 2MASS.

* RA/Dec in equinox J2000

Magnitudes depend on the catalogue. e.g. For Sloan, R is the Sloan r mag, not the Johnson R from APM, for example.