Swift Trigger: 1185673;

Presumed name: GRB 230816A

BAT	21^h 53^m 30.00^s, +37° 49′ 40.8″
position:	(328.375, 37.828 ± 180″)
XRT	21^h 53^m 46.78^s, +37° 51′ 17.9″
position:	(328.44492, 37.85498 ± 1.9″)
UVOT	No position available.
Galactic N_HI:	1.75×10²¹ cm^-2
Galactic E(B-V):	0.296 mag

Best RA:	21^h 53^m 46.78^s	= 328.44492 d
Best Dec:	+37° 51′ 17.9″	= 37.85498 d

Gal Lat:	-12.83
Gal Long:	88.41

Sun angle:	128.33°, 11.8 hr West

Galaxies within 200 of XRT position

	RA*	Dec*	Redshift		Catalogue
5.0	328.4442	37.8564			NED
10.6	328.4475	37.8572			NED
12.2	328.4417	37.8528			NED
18.9	328.4436	37.8601		B2=19.0, I=17.7, R1=18.4, R2=17.8	USNO-B1
19.4	328.4515	37.8564		B1=20.1, B2=18.4, I=17.5	USNO-B1
19.4	328.4513	37.8569			NED
19.7	328.4446	37.8606			NED
21.7	328.4501	37.8594		B2=21.8, R1=18.8	USNO-B1
23.4	328.4425	37.8489			NED
28.5	328.4369	37.8597		B1=19.9, I=17.4	USNO-B1
29.5	328.4346	37.8533			NED
33.6	328.4459	37.8457		B1=20.5, I=17.5, R1=19.4	USNO-B1
33.9	328.4346	37.8597			NED
34.2	328.4511	37.8631		I=18.8, R1=19.2	USNO-B1
36.7	328.4351	37.8484		B2=21.1, I=19.1, R1=19.3, R2=20.4	USNO-B1
40.6	328.4479	37.8439			NED
44.5	328.4579	37.8481			NED
46.6	328.4608	37.8575			NED
47.1	328.4296	37.8494			NED
49.4	328.4304	37.8628			NED
50.9	328.4558	37.8661			NED
52.5	328.4442	37.8403			NED
52.7	328.4613	37.8481		I=18.9, R2=20.2	USNO-B1
52.9	328.4562	37.8667		B1=18.9, B2=17.2, I=15.1, R1=16.7, R2=15.0	USNO-B1
53.6	328.4625	37.8606			NED
54.7	328.4561	37.8674		B2=16.1, R1=15.4	USNO-B1
55.0	328.4554	37.8422			NED
55.2	328.4559	37.8676		h=13.9, j=14.9, k=13.4	2MASS
55.3	328.4558	37.8675	0.076280		NED
57.1	328.4608	37.8647			NED
57.7	328.4433	37.8708			NED
57.7	328.4617	37.8640		B2=20.8, R2=18.3	USNO-B1
58.2	328.4246	37.8533		B1=20.2, B2=20.5, I=18.7, R1=18.6, R2=18.6	USNO-B1
58.3	328.4429	37.8711		I=17.8, R1=19.0	USNO-B1
59.1	328.4413	37.8711			NED
59.1	328.4475	37.8714			NED
60.1	328.4559	37.8692		I=18.5, R2=19.3	USNO-B1
60.2	328.4267	37.8639			NED
60.8	328.4559	37.8695		B2=20.7, I=18.2, R1=18.4, R2=19.5	USNO-B1
61.7	328.4654	37.8492			NED
63.1	328.4225	37.8536			NED
63.4	328.4257	37.8639		I=18.3, R1=18.8, R2=19.9	USNO-B1
64.0	328.4346	37.8708		R1=19.1, R2=18.9	USNO-B1
64.4	328.4233	37.8603			NED
64.4	328.4362	37.8714			NED
65.3	328.4664	37.8614		B2=20.1, I=18.8, R2=20.4	USNO-B1
65.6	328.4675	37.8525			NED
65.8	328.4333	37.8708			NED
66.7	328.4408	37.8733			NED
67.8	328.4237	37.8461			NED
68.6	328.4612	37.8692			NED
69.8	328.4483	37.8358			NED
70.4	328.4696	37.8522			NED
70.6	328.4612	37.8402		I=19.1, R1=19.2, R2=20.3	USNO-B1
71.0	328.4612	37.8400			NED
73.4	328.4473	37.8753		I=19.0, R1=19.3, R2=20.5	USNO-B1
73.6	328.4611	37.8390		I=19.1, R2=20.4	USNO-B1
75.4	328.4296	37.8381			NED
76.3	328.4694	37.8463		B2=20.4, I=17.6	USNO-B1
77.1	328.4708	37.8486		B1=19.5, I=18.3, R2=19.4	USNO-B1
77.5	328.4692	37.8453			NED
78.7	328.4437	37.8331			NED
78.8	328.4237	37.8408			NED
80.1	328.4527	37.8336		B2=20.6, R2=20.1	USNO-B1
82.7	328.4350	37.8333			NED
83.6	328.4504	37.8778			NED
84.5	328.4369	37.8324		B1=20.2, R2=20.1	USNO-B1
84.6	328.4529	37.8324		B2=21.3, R1=19.3	USNO-B1
85.0	328.4209	37.8409		I=18.5, R1=19.4	USNO-B1
85.8	328.4737	37.8614			NED
88.5	328.4175	37.8431			NED
90.4	328.4358	37.8792			NED
90.8	328.4296	37.8772			NED
91.4	328.4712	37.8406			NED
91.9	328.4321	37.8317			NED
92.0	328.4376	37.8301		B2=21.9, R2=20.6	USNO-B1
92.1	328.4258	37.8756			NED
93.8	328.4299	37.8782		B1=20.5, I=18.9, R1=19.5, R2=20.1	USNO-B1
94.4	328.4483	37.8289			NED
95.6	328.4758	37.8450			NED
95.8	328.4768	37.8636		B2=21.4, I=17.8, R1=19.1, R2=19.5	USNO-B1
95.9	328.4767	37.8639		B2=20.9, I=18.5, R1=19.0	USNO-B1
96.0	328.4767	37.8636			NED
96.8	328.4217	37.8747			NED
97.1	328.4125	37.8636			NED
98.8	328.4362	37.8817			NED
100.1	328.4443	37.8272		B2=20.9, R2=20.8	USNO-B1
100.7	328.4133	37.8681			NED
101.2	328.4134	37.8681		B2=21.0, I=18.9, R2=20.2	USNO-B1
102.0	328.4658	37.8322			NED
103.7	328.4675	37.8776		I=18.6, R2=19.5	USNO-B1
104.5	328.4475	37.8261			NED
104.6	328.4317	37.8819			NED
105.1	328.4779	37.8417		B2=21.3, I=18.4, R1=19.2, R2=19.7	USNO-B1
105.5	328.4079	37.8550			NED
105.8	328.4077	37.8549		h=14.6, j=15.6, k=14.1	2MASS
105.9	328.4779	37.8414			NED
108.8	328.4686	37.8787		B2=19.1, I=17.9	USNO-B1
109.0	328.4112	37.8406		B1=20.5, B2=20.9, R1=19.1, R2=20.2	USNO-B1
109.4	328.4529	37.8253			NED
109.6	328.4250	37.8811			NED
109.9	328.4398	37.8852		B2=17.1, I=15.9, R2=16.3	USNO-B1
110.3	328.4396	37.8853			NED
110.6	328.4383	37.8247		B1=20.7, R1=19.4	USNO-B1
112.3	328.4683	37.8803			NED
114.1	328.4760	37.8751		B2=20.2, I=18.7, R1=19.0, R2=19.2	USNO-B1
114.3	328.4677	37.8811		B2=19.4, I=14.5, R2=18.6	USNO-B1
114.7	328.4383	37.8864			NED
115.0	328.4527	37.8863		B1=20.4, B2=20.6, I=17.1	USNO-B1
115.0	328.4792	37.8722			NED
115.4	328.4523	37.8865		B2=20.4, I=17.4, R1=18.8, R2=18.9	USNO-B1
116.0	328.4383	37.8867			NED
116.8	328.4524	37.8869		B2=20.9, I=17.4, R1=18.8, R2=19.1	USNO-B1
117.5	328.4525	37.8869			NED
117.5	328.4390	37.8873		B2=17.7, R1=19.5	USNO-B1
117.6	328.4654	37.8267			NED
120.7	328.4137	37.8322			NED
121.0	328.4131	37.8326		B2=21.4, I=18.6, R1=19.4, R2=19.4	USNO-B1
123.8	328.4728	37.8814		B2=20.9, I=19.1, R2=19.8	USNO-B1
124.1	328.4333	37.8883			NED
124.7	328.4874	37.8463		B2=19.9, I=18.8	USNO-B1
125.4	328.4154	37.8292			NED
125.4	328.4877	37.8463		B1=19.6, B2=19.3, I=18.5, R1=18.5, R2=19.5	USNO-B1
126.5	328.4054	37.8714			NED
128.0	328.4220	37.8244		B1=20.4, B2=20.4, I=18.9, R1=18.9, R2=19.6	USNO-B1
128.4	328.4137	37.8808			NED
128.6	328.4021	37.8666		B1=19.9, B2=20.1, I=17.9, R1=19.1, R2=19.5	USNO-B1
129.8	328.4742	37.8828			NED
129.8	328.4600	37.8208			NED
130.1	328.4599	37.8208		I=19.0, R1=18.9, R2=20.3	USNO-B1
130.3	328.4204	37.8856		I=18.3, R2=20.4	USNO-B1
130.3	328.4204	37.8856			NED
130.7	328.4033	37.8706			NED
131.4	328.4822	37.8765		B2=20.8, R2=20.2	USNO-B1
131.5	328.4032	37.8708		B2=20.3, I=17.5, R1=18.5, R2=18.2	USNO-B1
131.5	328.4026	37.8403		B1=20.3, R2=20.0	USNO-B1
132.1	328.4330	37.8195		B2=20.8, R1=19.3, R2=19.9	USNO-B1
133.3	328.3981	37.8575		B2=20.8, I=18.6, R1=19.2	USNO-B1
133.4	328.4392	37.8917			NED
134.5	328.4142	37.8836			NED
134.6	328.4829	37.8775			NED
134.8	328.4829	37.8775		B2=20.9, I=17.6, R1=19.1, R2=19.5	USNO-B1
134.9	328.4429	37.8925			NED
135.4	328.4258	37.8206			NED
135.7	328.4050	37.8756			NED
136.0	328.3983	37.8456			NED
136.1	328.4434	37.8928		B2=20.9, I=18.6, R1=18.7, R2=19.4	USNO-B1
137.7	328.4325	37.8180		B2=20.4, I=18.0, R1=18.8, R2=18.7	USNO-B1
138.0	328.4000	37.8700			NED
138.3	328.4329	37.8178			NED
139.9	328.4937	37.8603			NED
140.2	328.4837	37.8311			NED
140.5	328.4617	37.8917			NED
140.5	328.4704	37.8883			NED
140.7	328.4444	37.8159		B2=20.7, I=18.0, R1=19.4, R2=19.3	USNO-B1
141.4	328.4439	37.8157		B2=19.6, I=18.6, R2=18.2	USNO-B1
141.5	328.4942	37.8603			NED
141.8	328.4946	37.8564			NED
142.4	328.4500	37.8156			NED
142.5	328.4308	37.8170		B2=20.9, I=19.1, R2=19.8	USNO-B1
142.5	328.4925	37.8675			NED
142.5	328.4925	37.8425			NED
142.8	328.4926	37.8426		B2=21.0, I=18.8, R2=19.7	USNO-B1
143.0	328.4536	37.8159		B1=20.0, B2=20.7, R2=19.6	USNO-B1
143.2	328.3954	37.8624		B2=20.5, R2=20.1	USNO-B1
143.6	328.4566	37.8162		I=18.9, R2=20.4	USNO-B1
144.2	328.4000	37.8736			NED
145.5	328.3998	37.8741		B1=17.5, B2=17.2, I=15.9, R1=16.6	USNO-B1
145.6	328.3937	37.8539			NED
145.9	328.4062	37.8283			NED
146.0	328.4792	37.8853			NED
147.2	328.4656	37.8175		B2=20.8, I=19.1, R2=20.0	USNO-B1
147.4	328.4254	37.8929		B2=20.8, I=18.6, R2=19.7	USNO-B1
147.4	328.3992	37.8747			NED
148.1	328.4837	37.8278			NED
148.4	328.4735	37.8205		I=18.7, R1=19.3, R2=20.4	USNO-B1
149.7	328.4917	37.8356			NED
149.7	328.3992	37.8756		I=18.5, R1=19.5, R2=18.8	USNO-B1
149.8	328.3996	37.8761			NED
150.1	328.3958	37.8400			NED
150.5	328.4504	37.8133			NED
150.6	328.4883	37.8789			NED
150.8	328.4914	37.8348		B2=21.3, I=19.0, R1=19.2, R2=20.4	USNO-B1
151.4	328.4704	37.8919			NED
151.9	328.4050	37.8828			NED
152.2	328.4201	37.8175		B2=21.0, I=18.5, R2=19.9	USNO-B1
152.9	328.3925	37.8644			NED
153.1	328.3918	37.8619		B2=21.4, I=18.5, R1=19.2, R2=20.0	USNO-B1
153.3	328.4293	37.8142		I=18.9, R2=19.8	USNO-B1
153.5	328.3917	37.8619			NED
153.7	328.4767	37.8206			NED
153.7	328.4292	37.8142			NED
154.3	328.4779	37.8889			NED
156.3	328.4910	37.8313		B2=20.7, I=18.5, R2=20.0	USNO-B1
157.4	328.4983	37.8664			NED
157.5	328.4653	37.8143		B2=20.8, I=19.0, R2=20.2	USNO-B1
157.6	328.3929	37.8703			NED
157.8	328.4986	37.8663		I=19.0, R2=19.9	USNO-B1
158.4	328.4833	37.8869			NED
158.5	328.4657	37.8141		I=18.6, R2=20.2	USNO-B1
158.5	328.4013	37.8275			NED
158.8	328.4870	37.8840		B2=20.4, I=17.6, R1=18.7, R2=18.7	USNO-B1
158.9	328.4362	37.8986			NED
159.1	328.4996	37.8453			NED
159.1	328.4658	37.8139			NED
159.5	328.4997	37.8453		I=18.7, R2=20.0	USNO-B1
159.9	328.4867	37.8847			NED
160.0	328.3933	37.8367			NED
160.7	328.4667	37.8961			NED
161.1	328.4538	37.8992			NED
161.8	328.4237	37.8131			NED
162.5	328.4468	37.9001		B1=19.8, B2=20.6, I=18.4, R1=19.4, R2=19.2	USNO-B1
162.7	328.3892	37.8439			NED
163.5	328.3879	37.8478			NED
163.9	328.4317	37.8992			NED
164.3	328.4316	37.8994		B2=21.4, I=18.5, R2=19.5	USNO-B1
164.4	328.3879	37.8475		B2=20.0, I=18.3, R2=20.1	USNO-B1
164.6	328.4368	37.9003		B2=21.2, I=19.0, R2=20.1	USNO-B1
164.9	328.4117	37.8928			NED
165.4	328.4950	37.8783			NED
166.6	328.3892	37.8697			NED
166.6	328.4860	37.8220		I=19.0, R1=19.4, R2=20.2	USNO-B1
167.6	328.4479	37.9014			NED
167.8	328.4412	37.9015		B1=18.8, B2=20.6, I=18.7, R2=19.2	USNO-B1
168.0	328.4737	37.8144			NED
168.3	328.4620	37.8102		B1=18.3, B2=19.8, I=18.6	USNO-B1
168.5	328.4481	37.9017		B1=20.3, B2=20.8, I=18.4, R1=19.0, R2=19.3	USNO-B1
168.7	328.4258	37.8106			NED
168.8	328.4646	37.8992			NED
169.3	328.4478	37.9020		B2=20.8, R2=20.1	USNO-B1
169.3	328.4400	37.9019			NED
169.9	328.4604	37.8094		B2=19.0, I=18.1, R2=17.9	USNO-B1
170.0	328.4608	37.8094			NED
170.2	328.5004	37.8725			NED
170.2	328.5005	37.8727		B1=20.1, B2=20.5, I=18.0, R1=18.7, R2=19.0	USNO-B1
170.7	328.3850	37.8583			NED
170.8	328.4676	37.8111		B1=20.1, B2=20.9, R2=19.9	USNO-B1
170.8	328.4497	37.8077		B2=20.7, I=18.4, R1=19.1, R2=19.7	USNO-B1
171.0	328.4297	37.9009		B1=20.0, B2=20.4, I=18.5, R1=18.8, R2=19.0	USNO-B1
172.4	328.4117	37.8147			NED
172.5	328.4058	37.8917			NED
172.5	328.4062	37.8919			NED
172.6	328.4084	37.8167		B2=20.7, I=18.5, R1=19.0, R2=19.8	USNO-B1
173.0	328.3845	37.8606		B2=20.8, R2=19.6	USNO-B1
173.6	328.5054	37.8617			NED
173.9	328.4350	37.9028			NED
174.1	328.4494	37.8068		B2=20.6, I=18.0, R1=19.0	USNO-B1
174.2	328.4346	37.9027		I=19.0, R2=20.0	USNO-B1
174.4	328.4504	37.9033			NED
174.8	328.4057	37.8924		I=17.2, R2=19.8	USNO-B1
174.8	328.5042	37.8675			NED
175.2	328.3856	37.8417		B2=21.7, I=18.6, R1=19.4, R2=20.5	USNO-B1
175.4	328.3858	37.8414			NED
175.4	328.3833	37.8497			NED
175.6	328.4183	37.8108			NED
175.7	328.4946	37.8261			NED
176.0	328.4111	37.8140		B2=21.1, I=18.3, R1=19.1, R2=19.2	USNO-B1
176.2	328.4746	37.8981			NED
176.2	328.4812	37.8947			NED
176.6	328.4611	37.8076		B2=20.7, I=18.5, R1=19.2, R2=19.4	USNO-B1
177.9	328.4171	37.8992			NED
178.0	328.3858	37.8711			NED
178.3	328.4492	37.8056			NED
178.9	328.3942	37.8844			NED
179.0	328.4282	37.8070		I=18.9, R1=18.8	USNO-B1
179.1	328.3879	37.8339			NED
179.3	328.4751	37.8987		B2=20.6, I=17.8, R2=18.7	USNO-B1
179.3	328.5029	37.8354		I=19.1, R2=20.7	USNO-B1
180.6	328.4975	37.8831			NED
181.2	328.3843	37.8707		I=18.5, R2=20.0	USNO-B1
181.4	328.4743	37.8102		I=19.1, R2=20.6	USNO-B1
181.7	328.3950	37.8864			NED
181.9	328.3980	37.8206		B1=19.7, B2=20.4, I=18.5, R1=19.2, R2=19.3	USNO-B1
182.1	328.3904	37.8817			NED
182.1	328.4554	37.8050			NED
182.3	328.3906	37.8819		B2=18.1, I=15.4	USNO-B1
182.5	328.4321	37.8053			NED
182.7	328.3913	37.8828			NED
182.7	328.5006	37.8297		B2=20.4, R2=20.1	USNO-B1
183.2	328.4325	37.8050			NED
183.6	328.4946	37.8225			NED
184.0	328.4929	37.8892			NED
184.5	328.3963	37.8211			NED
184.8	328.5054	37.8733			NED
184.8	328.5062	37.8722			NED
184.8	328.4919	37.8905		I=19.1, R1=19.2	USNO-B1
184.9	328.5046	37.8756			NED
185.5	328.4500	37.9064			NED
186.4	328.4929	37.8903		B1=19.5, I=16.2, R2=16.3	USNO-B1
187.1	328.4304	37.9058			NED
187.7	328.3854	37.8319			NED
187.8	328.5054	37.8344			NED
187.8	328.5075	37.8717		B2=20.9, I=18.2, R1=18.9, R2=19.2	USNO-B1
188.9	328.5112	37.8561			NED
189.1	328.3925	37.8228			NED
189.1	328.4937	37.8908			NED
190.4	328.3804	37.8408			NED
191.7	328.4808	37.9001		B1=19.3, B2=20.9	USNO-B1
192.2	328.4979	37.8219			NED
192.5	328.4211	37.8049		R1=19.5, R2=20.1	USNO-B1
193.0	328.4617	37.8031			NED
193.9	328.4867	37.8975			NED
194.5	328.3850	37.8814			NED
194.6	328.4979	37.8894			NED
194.6	328.4937	37.8169			NED
194.7	328.3950	37.8181			NED
194.8	328.4279	37.8025			NED
195.0	328.4154	37.8061			NED
195.0	328.4531	37.8012		B2=21.5, I=18.3, R1=19.1, R2=19.4	USNO-B1
195.4	328.4529	37.8011			NED
196.0	328.3950	37.8925			NED
196.3	328.3765	37.8474		B2=20.6, R2=20.1	USNO-B1
196.6	328.3946	37.8925		B1=19.6, I=16.9	USNO-B1
196.6	328.4679	37.9064			NED
197.2	328.4828	37.8091		B2=20.7, I=18.9, R1=19.1, R2=20.2	USNO-B1
197.5	328.4137	37.9042			NED
197.6	328.4683	37.9067			NED
197.6	328.4055	37.8098		B1=20.2, B2=17.5	USNO-B1
197.6	328.3901	37.8212		B2=19.9, R1=19.5	USNO-B1
197.7	328.4139	37.9041		B2=20.9, I=18.1, R2=20.0	USNO-B1
198.4	328.4904	37.8967			NED
198.4	328.4747	37.9048		B2=20.9, R2=19.8	USNO-B1
198.7	328.3750	37.8597			NED
198.9	328.4785	37.8065		I=19.1, R2=20.8	USNO-B1
199.1	328.4867	37.8106		B2=20.9, R2=20.7	USNO-B1
199.3	328.3750	37.8506			NED
199.6	328.4083	37.9025			NED

Queried APM-N, SDSS, PSCz, SSS, NED, 2MASSX, USNO-B1.

* 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