Swift Trigger: 900730;

Presumed name: GRB 190427A

BAT	18^h 40^m 51.12^s, +40° 19′ 19.2″
position:	(280.213, +40.322 ± 180″)
XRT	No position available.
UVOT	No position available.
Galactic N_HI:	6.06×10⁰ cm^-2
Galactic E(B-V):	0.069 mag

Best RA:	18^h 40^m 51.12^s	= 280.213 d
Best Dec:	+40° 19′ 19.2″	= +40.322 d

Gal Lat:	19.05
Gal Long:	69.25

Sun angle:	98.44°, 7.6 hr West

Galaxies within 3.33 of BAT position

	RA*	Dec*	Redshift		Catalogue
30.3	280.2225	40.3177		I=18.3, R2=19.9	USNO-B1
36.2	280.2068	40.3131		B1=20.7, B2=21.3	USNO-B1
39.1	280.2154	40.3114			NED
39.8	280.2142	40.3111			NED
49.4	280.2050	40.3097			NED
53.6	280.1940	40.3254		B1=18.9, B2=18.2, I=16.9, R1=17.6, R2=17.0	USNO-B1
54.1	280.2294	40.3303		B=20.6, R=18.6	APM-N
62.3	280.2292	40.3342			NED
63.6	280.1969	40.3347		B1=20.7, B2=20.9, I=18.3, R1=18.3, R2=19.1	USNO-B1
63.7	280.1970	40.3348		B=22.1, R=19.0	APM-N
64.9	280.2358	40.3172			NED
67.0	280.1887	40.3253			NED
70.3	280.2328	40.3096		B2=21.2, R2=20.2	USNO-B1
71.4	280.1879	40.3161			NED
71.7	280.1878	40.3166		I=18.1, R1=19.1	USNO-B1
72.5	280.2392	40.3253			NED
75.2	280.1873	40.3147		B=19.6, R=15.8	APM-N
75.4	280.2195	40.3016		B1=18.6, B2=20.3	USNO-B1
76.0	280.2191	40.3014		B2=17.9, I=15.5, R1=16.1, R2=16.1	USNO-B1
76.1	280.2188	40.3014	-0.000307		NED
77.3	280.2275	40.3036			NED
79.0	280.2125	40.3000			NED
79.8	280.1863	40.3133			NED
81.2	280.2092	40.2997			NED
81.2	280.1892	40.3356			NED
84.5	280.1823	40.3231		B=21.3, R=20.0	APM-N
85.1	280.2337	40.3047			NED
89.1	280.1840	40.3109		I=18.1, R1=19.5, R2=20.3	USNO-B1
90.8	280.2393	40.3374		I=18.2, R1=19.3, R2=19.8	USNO-B1
91.1	280.1798	40.3222		B=22.1, R=19.2	APM-N
91.4	280.1796	40.3219			NED
94.6	280.2017	40.3467			NED
95.6	280.1821	40.3100			NED
96.1	280.2476	40.3264		B=18.6, R=17.5	APM-N
96.2	280.2475	40.3261			NED
96.5	280.2221	40.2961			NED
97.6	280.2208	40.3483			NED
97.9	280.1774	40.3235		B1=18.4, B2=17.6, I=15.6, R1=16.0, R2=16.1	USNO-B1
98.0	280.1771	40.3233			NED
99.9	280.2245	40.3483		I=18.4, R2=19.6	USNO-B1
103.0	280.1759	40.3175		I=18.9, R1=19.1	USNO-B1
103.3	280.1767	40.3144			NED
104.3	280.2427	40.3040		B=19.4, R=17.0	APM-N
104.9	280.2300	40.3481			NED
105.2	280.2425	40.3036			NED
107.0	280.2063	40.2928			NED
113.0	280.1890	40.2965		I=18.8, R1=19.0, R2=19.7	USNO-B1
113.1	280.2387	40.2975			NED
117.7	280.2212	40.3542			NED
118.4	280.2225	40.3542			NED
120.3	280.1724	40.3093		B=21.2, R=19.5	APM-N
120.5	280.2425	40.3467			NED
121.6	280.2571	40.3225			NED
124.5	280.1824	40.2965		B1=20.9, B2=21.1	USNO-B1
126.0	280.1885	40.3516		B1=20.8, B2=21.5, I=17.9, R2=19.8	USNO-B1
126.4	280.1742	40.3411			NED
126.6	280.2542	40.3379		B=20.6, R=19.3	APM-N
126.8	280.2358	40.2914		I=18.9, R2=20.1	USNO-B1
128.0	280.2567	40.3094			NED
128.0	280.1738	40.3028			NED
128.0	280.1673	40.3291		B=21.7, R=20.0	APM-N
130.7	280.2529	40.3419			NED
130.9	280.2333	40.3550			NED
131.0	280.2531	40.3417		B=20.7, R=18.1	APM-N
131.4	280.2583	40.3339		B=21.3, R=19.3	APM-N
132.7	280.2522	40.3004		B=20.2, R=17.3	APM-N
132.8	280.1700	40.3392			NED
133.0	280.2521	40.3003			NED
133.7	280.1801	40.3494		B2=21.2, I=18.8, R1=19.5, R2=19.8	USNO-B1
135.0	280.2617	40.3167		I=18.8, R2=19.9	USNO-B1
135.0	280.2167	40.2847			NED
135.7	280.2257	40.3584		B2=21.1, R2=20.2	USNO-B1
137.2	280.1750	40.3467		B1=20.5, B2=19.7, I=16.8, R1=17.4, R2=17.6	USNO-B1
137.2	280.1750	40.3467			NED
137.3	280.2629	40.3225			NED
137.4	280.2329	40.3569			NED
137.8	280.1629	40.3172			NED
139.7	280.1625	40.3171		B1=16.8, B2=16.4, I=15.2, R1=15.2, R2=15.6	USNO-B1
140.4	280.2484	40.2939		B1=20.2, B2=19.8, I=18.4, R1=19.0, R2=19.2	USNO-B1
141.1	280.1621	40.3169			NED
141.6	280.1917	40.3578			NED
142.0	280.1964	40.3594		B1=20.6, R2=20.0	USNO-B1
142.2	280.1613	40.3217			NED
144.1	280.2238	40.2828		B2=20.9, I=17.6, R1=18.4, R2=19.0	USNO-B1
144.2	280.2238	40.2828			NED
146.0	280.1871	40.2867			NED
146.8	280.1975	40.2831			NED
148.0	280.1738	40.2938		B1=20.8, B2=20.4, I=17.6, R1=18.1, R2=18.6	USNO-B1
148.1	280.1738	40.2936			NED
148.9	280.1771	40.3531			NED
149.0	280.1842	40.3572			NED
149.2	280.1900	40.3594			NED
149.9	280.1769	40.3532		B1=19.4, B2=18.5, I=17.1, R1=17.2, R2=17.3	USNO-B1
150.1	280.1899	40.3598		B=22.1, R=18.9	APM-N
150.5	280.1856	40.2858		B1=19.9, B2=19.4, I=18.2, R1=18.3	USNO-B1
151.7	280.1746	40.2917			NED
152.9	280.1633	40.3028			NED
152.9	280.2684	40.3176		B=21.2, R=18.8	APM-N
153.4	280.2125	40.3647			NED
155.4	280.1674	40.2964		B1=20.9, B2=21.6, R2=20.1	USNO-B1
155.9	280.2300	40.3633			NED
156.8	280.1714	40.2922		I=18.2, R2=20.0	USNO-B1
159.5	280.2079	40.3661			NED
162.1	280.2721	40.3214		B=20.2, R=18.6	APM-N
163.6	280.2631	40.3466		B2=21.1, R2=19.9	USNO-B1
163.7	280.2279	40.3661			NED
163.9	280.1587	40.3414			NED
164.9	280.2729	40.3261			NED
165.1	280.2704	40.3083			NED
165.4	280.2308	40.2781			NED
166.6	280.1992	40.3672			NED
168.8	280.2496	40.2842			NED
169.1	280.2504	40.2847		B=18.2, R=16.0	APM-N
169.3	280.2588	40.2906			NED
170.2	280.2508	40.2847			NED
170.9	280.2174	40.3694		B=22.1, R=20.0	APM-N
172.5	280.2482	40.3617		B1=20.9, B2=21.1, R2=20.0	USNO-B1
172.9	280.1531	40.3369		B1=19.1, B2=18.2, I=16.5, R1=16.9, R2=17.0	USNO-B1
173.0	280.1529	40.3369			NED
176.0	280.1492	40.3269			NED
176.6	280.2279	40.3697			NED
176.9	280.1779	40.2808			NED
177.4	280.1704	40.3592			NED
178.2	280.2486	40.3634		B1=20.6, B2=20.4, R2=19.2	USNO-B1
178.9	280.2604	40.3561			NED
179.1	280.2124	40.3718		B2=21.4, I=18.9	USNO-B1
179.3	280.2704	40.3456			NED
179.3	280.2706	40.3455		I=18.4, R1=19.3, R2=20.0	USNO-B1
180.8	280.1879	40.2756			NED
181.6	280.2138	40.2717			NED
182.4	280.1467	40.3192			NED
183.5	280.2561	40.2830		B1=16.6, B2=16.3, I=14.8, R1=15.0, R2=15.3	USNO-B1
183.5	280.2558	40.2831			NED
184.0	280.1492	40.3061			NED
184.7	280.2800	40.3247			NED
185.2	280.1592	40.2911			NED
185.2	280.2804	40.3211			NED
185.6	280.2600	40.3589			NED
186.3	280.2679	40.2916		B2=21.5, R1=18.6	USNO-B1
186.7	280.1662	40.3594			NED
187.7	280.2733	40.2978			NED
188.8	280.2739	40.2976		B=22.0, R=19.1	APM-N
189.7	280.1525	40.2964			NED
189.8	280.2650	40.2875			NED
191.6	280.2637	40.2856			NED
192.3	280.1533	40.3500		B=20.7, R=19.4	APM-N
193.1	280.1683	40.3633			NED
195.3	280.1851	40.2721		B1=20.8, B2=20.4, R1=19.6, R2=19.7	USNO-B1
195.7	280.1858	40.3722			NED
197.0	280.2842	40.3149		B2=21.6, I=18.7, R1=19.6, R2=20.1	USNO-B1
199.9	280.2208	40.2669			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