Swift Trigger: 425151;

Presumed name: GRB 100621A

BAT	21^h 01^m 13.92^s, -51° 05′ 11.0″
position:	(315.308, -51.0864 ± 180″)
XRT	21^h 01^m 13.25^s, -51° 06′ 22.0″
position:	(315.3052, -51.1061 ± 2.1″)
UVOT	No position available.
Galactic N_HI:	0.00×10⁰ cm^-2
Galactic E(B-V):	0.030 mag

Best RA:	21^h 01^m 13.25^s	= 315.3052 d
Best Dec:	-51° 06′ 22.0″	= -51.1061 d

Gal Lat:
Gal Long:

Sun angle:	not found

Stars within 3.33 of XRT position

	RA*	Dec*		Catalogue
25.5	315.3163	-51.1049	B2=18.3, I=17.8, R1=18.0, R2=17.9	USNO-B1
30.5	315.3074	-51.0977	R1=19.6, R2=24.0	USNO-B1
30.5	315.3090	-51.1142	B2=20.9, I=18.3, R1=19.5, R2=23.1	USNO-B1
32.0	315.3004	-51.0977	B2=20.3, R1=19.6	USNO-B1
33.1	315.3057	-51.1153	B2=20.6, R2=23.1	USNO-B1
34.6	315.2899	-51.1062	B2=19.8, I=17.0, R1=18.1, R2=18.5	USNO-B1
34.9	315.2898	-51.1062	h=14.7, j=15.3, k=14.3	2MASS
40.8	315.3232	-51.1066	B2=20.8, R1=19.1, R2=20.4	USNO-B1
54.0	315.3121	-51.1204	I=18.3, R1=19.6, R2=20.0	USNO-B1
54.2	315.2847	-51.0983	B2=20.1, R1=19.4, R2=19.9	USNO-B1
56.6	315.2949	-51.0918	h=14.4, j=14.8, k=14.3	2MASS
57.7	315.2947	-51.0915	B2=16.1, I=15.2, R1=15.2, R2=15.4	USNO-B1
59.8	315.2851	-51.1169	B2=20.5, R1=19.2	USNO-B1
60.0	315.2948	-51.0908	B2=18.5, I=16.8, R1=18.0, R2=17.1	USNO-B1
60.3	315.3307	-51.1011	h=16.2, j=16.4, k=15.8	2MASS
63.4	315.2950	-51.0897	B2=20.9, R1=19.5	USNO-B1
65.2	315.3024	-51.0881	h=13.4, j=14.0, k=13.3	2MASS
65.4	315.3060	-51.1243	B2=19.7, I=17.9, R1=19.2, R2=19.8	USNO-B1
65.6	315.3025	-51.0880	B2=16.4, I=14.6, R1=15.0, R2=15.2	USNO-B1
67.4	315.2889	-51.0904	B2=20.6, R2=23.5	USNO-B1
77.5	315.2855	-51.1237	I=18.2, R1=19.5, R2=24.8	USNO-B1
77.7	315.3367	-51.0975	B2=20.7, I=18.3, R1=19.3, R2=19.3	USNO-B1
79.7	315.3296	-51.1221	B2=20.8, I=18.4, R1=19.3, R2=19.4	USNO-B1
80.8	315.3306	-51.1219	I=18.3, R1=19.6	USNO-B1
82.5	315.3024	-51.1289	I=18.4, R2=23.4	USNO-B1
85.1	315.3409	-51.1136	B2=20.7, R2=23.2	USNO-B1
85.1	315.3028	-51.1297	B2=19.8, I=18.4, R1=19.3, R2=19.7	USNO-B1
89.8	315.3296	-51.0864	B2=20.8, R2=25.0	USNO-B1
90.1	315.2950	-51.0819	h=14.0, j=14.4, k=13.9	2MASS
91.7	315.2677	-51.0963	B2=20.8, R2=20.5	USNO-B1
93.6	315.2804	-51.1269	B2=20.8, I=18.4, R1=19.6, R2=23.1	USNO-B1
94.4	315.2722	-51.1221	h=16.2, j=16.6, k=15.7	2MASS
98.1	315.2622	-51.1099	B2=20.8, R1=19.4, R2=20.2	USNO-B1
98.3	315.2730	-51.1245	I=18.1, R1=19.2, R2=19.9	USNO-B1
98.4	315.2730	-51.1245	h=15.6, j=16.6, k=15.3	2MASS
99.3	315.2812	-51.0830	B2=20.1, R1=19.7, R2=23.9	USNO-B1
101.2	315.3026	-51.1342	I=18.4, R1=18.5, R2=18.3	USNO-B1
101.4	315.3332	-51.0841	B2=20.8, R2=23.8	USNO-B1
101.7	315.3023	-51.1343	B2=18.4, I=18.3, R1=18.9, R2=19.7	USNO-B1
103.6	315.3015	-51.1348	I=18.3, R2=23.7	USNO-B1
108.5	315.2717	-51.1277	B2=16.7, I=15.8, R1=15.9, R2=16.2	USNO-B1
108.6	315.2717	-51.1277	h=14.9, j=15.3, k=14.8	2MASS
117.5	315.3330	-51.0785	B2=20.8, I=18.3, R2=20.5	USNO-B1
117.7	315.3232	-51.0754	B2=20.4, R1=19.5, R2=20.2	USNO-B1
119.0	315.3492	-51.0879	B2=20.7, R1=19.6, R2=20.0	USNO-B1
120.4	315.2967	-51.1391	B2=18.7, I=18.2	USNO-B1
126.2	315.3573	-51.1188	B2=17.3, I=15.1, R1=15.7, R2=15.8	USNO-B1
126.4	315.3573	-51.1189	h=13.8, j=14.4, k=13.6	2MASS
126.5	315.2735	-51.0772	B2=20.9, I=18.4, R1=19.4, R2=19.5	USNO-B1
126.7	315.2656	-51.0812	B2=20.9, R1=19.4, R2=20.2	USNO-B1
127.1	315.2570	-51.0879	h=16.2, j=16.6, k=15.6	2MASS
127.1	315.2570	-51.0879	B2=20.6, I=18.1, R1=19.1, R2=19.5	USNO-B1
134.7	315.2651	-51.1338	h=16.3, j=16.8, k=15.8	2MASS
135.1	315.2649	-51.1338	B2=20.0, I=18.0, R1=18.6, R2=19.1	USNO-B1
135.4	315.3451	-51.1342	B2=20.1, R1=19.2, R2=19.7	USNO-B1
136.4	315.3414	-51.1364	B2=20.2, I=18.1, R1=18.8, R2=19.1	USNO-B1
137.0	315.2564	-51.1287	B2=14.2, I=12.7, R1=13.2, R2=13.6	USNO-B1
137.0	315.2565	-51.1288	h=11.8, j=12.3, k=11.7	2MASS
139.3	315.2599	-51.0798	B2=19.1, I=18.3, R1=18.6, R2=19.1	USNO-B1
139.9	315.2881	-51.1435	B2=16.4, I=14.1, R1=14.7, R2=15.0	USNO-B1
139.9	315.3645	-51.1173	B2=14.5, I=13.2, R1=13.5, R2=13.9	USNO-B1
140.0	315.3645	-51.1174	h=12.6, j=13.0, k=12.5	2MASS
140.2	315.2882	-51.1435	h=12.8, j=13.5, k=12.7	2MASS
143.2	315.2504	-51.0862	B2=20.7, R2=23.9	USNO-B1
143.2	315.2646	-51.0756	B2=20.9, R1=19.7, R2=23.4	USNO-B1
144.6	315.2425	-51.0983	B2=19.5, R1=19.1, R2=20.1	USNO-B1
145.7	315.2871	-51.0672	h=14.3, j=14.6, k=14.2	2MASS
146.1	315.2871	-51.0671	B2=15.8, I=14.9, R1=15.1, R2=15.4	USNO-B1
146.9	315.2403	-51.1081	B2=20.7, R1=19.6, R2=20.5	USNO-B1
149.7	315.2603	-51.0755	B2=20.7, R2=24.7	USNO-B1
150.6	315.3671	-51.0906	B2=20.0, I=18.1, R1=18.6, R2=18.9	USNO-B1
152.8	315.2925	-51.0644	h=16.0, j=16.4, k=16.0	2MASS
153.2	315.3666	-51.0882	I=18.3, R1=19.7	USNO-B1
153.2	315.2928	-51.0643	B2=17.7, I=17.4, R1=16.9, R2=17.3	USNO-B1
154.4	315.3671	-51.0879	B2=20.9, I=18.3, R1=19.4, R2=19.9	USNO-B1
156.7	315.3494	-51.0726	B2=20.3, R1=19.4, R2=20.0	USNO-B1
158.1	315.3202	-51.0632	h=14.9, j=15.4, k=14.4	2MASS
158.3	315.3203	-51.0632	B2=20.0, I=17.2, R1=18.3, R2=18.8	USNO-B1
158.5	315.2701	-51.0680	B2=20.6, I=17.9, R1=18.7, R2=19.6	USNO-B1
158.8	315.2700	-51.0680	h=15.6, j=16.4, k=15.3	2MASS
159.8	315.2349	-51.1108	B2=20.8, R2=19.9	USNO-B1
160.3	315.3528	-51.1391	B2=18.8, I=18.3, R1=18.5, R2=18.8	USNO-B1
160.9	315.2908	-51.0623	B2=20.3, R1=19.6, R2=20.6	USNO-B1
161.0	315.2344	-51.1108	B2=16.4, R1=19.1, R2=18.8	USNO-B1
161.3	315.3248	-51.0630	h=16.2, j=17.0, k=15.8	2MASS
164.3	315.2432	-51.1299	B2=20.9, R2=20.2	USNO-B1
165.0	315.3189	-51.1511	B2=19.5, I=17.8, R1=18.0, R2=18.0	USNO-B1
165.2	315.3189	-51.1512	h=15.6, j=16.3, k=15.5	2MASS
165.9	315.2725	-51.1474	B2=19.5, I=18.2, R1=18.6, R2=19.1	USNO-B1
166.3	315.3101	-51.0600	h=13.8, j=14.2, k=13.8	2MASS
166.7	315.3102	-51.0599	B2=15.6, I=14.5, R1=14.7, R2=14.9	USNO-B1
167.9	315.2313	-51.1109	B2=14.9, R2=18.9	USNO-B1
168.9	315.3776	-51.1177	B2=19.1, I=18.4, R1=18.9, R2=19.2	USNO-B1
169.0	315.3249	-51.0608	B2=20.5, R2=19.7	USNO-B1
170.3	315.3051	-51.1534	B2=18.4, R1=19.6, R2=20.2	USNO-B1
174.7	315.2503	-51.1403	B2=19.4, I=17.1, R1=18.0, R2=18.2	USNO-B1
174.9	315.2503	-51.1403	h=14.9, j=15.5, k=14.7	2MASS
175.0	315.3684	-51.0780	B2=20.7, I=18.4, R1=19.4, R2=19.6	USNO-B1
176.2	315.2274	-51.1035	B2=19.5, R2=20.2	USNO-B1
178.4	315.3091	-51.1556	B2=19.9, R2=20.1	USNO-B1
178.6	315.2653	-51.1489	B2=15.3, I=14.1, R1=14.4, R2=14.7	USNO-B1
178.9	315.2653	-51.1490	h=13.5, j=13.9, k=13.5	2MASS
179.3	315.2284	-51.0936	B2=20.3, R1=19.4, R2=20.4	USNO-B1
179.3	315.2348	-51.0832	h=16.0, j=16.6, k=16.6	2MASS
179.5	315.2347	-51.0831	B2=18.5, I=17.7, R1=17.6, R2=18.0	USNO-B1
180.0	315.2440	-51.1381	B2=19.9, R1=19.6, R2=20.3	USNO-B1
180.2	315.3408	-51.0613	B2=20.3, R1=19.4, R2=20.1	USNO-B1
181.5	315.2521	-51.0683	B2=20.7, R1=19.7, R2=23.0	USNO-B1
181.6	315.3794	-51.0867	B2=19.7, R1=19.1, R2=20.1	USNO-B1
183.1	315.3226	-51.0564	h=14.5, j=15.1, k=14.5	2MASS
183.5	315.3227	-51.0563	B2=17.0, I=16.0, R1=16.0, R2=16.1	USNO-B1
183.7	315.3076	-51.0551	B2=20.9, R2=24.3	USNO-B1
185.3	315.2533	-51.0663	h=15.1, j=15.7, k=14.9	2MASS
187.7	315.2452	-51.0701	h=14.1, j=14.6, k=14.2	2MASS
187.9	315.2452	-51.0700	B2=16.4, I=15.2, R1=15.4, R2=15.7	USNO-B1
188.9	315.2377	-51.1371	B2=17.9, I=17.6, R1=17.4, R2=17.7	USNO-B1
189.7	315.3483	-51.1513	B2=18.5, I=18.0, R1=18.1, R2=18.1	USNO-B1
189.8	315.2874	-51.0546	B2=18.9, I=18.2, R1=19.0, R2=19.2	USNO-B1
190.1	315.2270	-51.0867	B2=18.8, I=18.0, R1=17.9, R2=18.2	USNO-B1
191.1	315.2666	-51.0589	h=16.0, j=16.9, k=15.3	2MASS
191.5	315.2856	-51.0544	B2=20.6, R2=20.4	USNO-B1
192.0	315.3099	-51.1594	R1=19.4, R2=20.2	USNO-B1
193.1	315.2203	-51.1002	B2=16.8, R1=19.5, R2=20.3	USNO-B1
193.2	315.2199	-51.1022	B2=20.0, R2=18.2	USNO-B1
193.4	315.2197	-51.1053	B2=16.4, R1=19.0, R2=18.3	USNO-B1
193.6	315.2198	-51.1018	B2=20.2, R2=19.4	USNO-B1
193.7	315.2199	-51.1109	h=9.0, j=9.3, k=8.8	2MASS
194.3	315.3911	-51.1036	B2=19.6, I=17.8, R1=18.3, R2=18.7	USNO-B1
195.7	315.2650	-51.0580	B2=18.5, I=16.7, R1=16.3	USNO-B1
196.2	315.3146	-51.0519	h=14.1, j=14.4, k=13.9	2MASS
196.3	315.2222	-51.0902	B2=18.5, I=18.3, R1=18.5, R2=18.5	USNO-B1
196.8	315.2197	-51.1163	B2=16.4, I=17.5, R2=16.8	USNO-B1
197.3	315.2643	-51.0577	B2=15.1, I=13.7, R1=14.1, R2=14.3	USNO-B1
197.7	315.2197	-51.1175	B2=17.1, R2=20.3	USNO-B1
198.2	315.2640	-51.0575	h=12.9, j=13.4, k=12.8	2MASS
199.5	315.3224	-51.1605	B2=20.6, R2=19.9	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.