Table 1: Observations for the analysis of the three X-ray transients: TR1 (XMMU J004215.8+411924), TR2 (SWIFT J004217.4+411532), and TR3 (M31N 2006-11a).

Observation	Date	Observatory	Instrument	Obs-ID	TR1	TR2	TR3
1	2006 Jun. 05	Chandra	HRC-I	7283	-	-	-
2	2006 Jul. 02	XMM	EPIC	0405320501	-	-	-
3	2006 Jul. 31	Chandra	ACIS-I	7139	+	-	-
4	2006 Aug. 09	XMM	EPIC	0405320601	+	-	-
5	2006 Sep. 01	Swift	XRT	00030802001	+	+	-
6	2006 Sep. 11	Swift	XRT	00030804001	-	+	-
7	2006 Sep. 24	Chandra	ACIS-I	7140	-	+
8	2006 Sep. 30	Chandra	HRC-I	7284	-	+	-
9	2006 Nov. 13	Chandra	HRC-I	7285	-	+	-
10	2006 Dec. 4	Chandra	ACIS-I	7064		+
11	2006 Dec. 31	XMM	EPIC	0405320701	-	+	-
12	2007 Jan. 16	XMM	EPIC	0405320801	-	+	-
13	2007 Mar. 11	Chandra	HRC-I	7286	-	-	-
14	2007 Jun. 01	Swift	XRT	00035336001	-	-	+
15	2007 Jul. 12	Swift	XRT	00030968001	-	-	-
16	2007 Jul. 13	Swift	XRT	00030968002	-	-	-
17	2007 Jul. 18	Swift	XRT	00030968004	-	-	-

Note: a + signifies that the source was detected in this observation, whereas a - signifies that it was not detected.