Table 2: Integration times and disk magnitude limits. The latter ones were determined with artificial disks of the sizes shown in this table. No disk was found down to the given surface brightness. The reduction routine has a lower performance for stars in clusters and a determination of brightness limits was sometimes not possible. These cases are indicated with "-''. Estimated errors for the given magnitudes are $\pm$ 0.2 mag. The disk brightness limit as a function of disk radius was studied in more detail for the targets HD 4208, HD 33636 and HD 217107 with further radii 1.0, 1.8, 2.5, 3.3, 4.0 and 4.8 $^{\prime \prime }$ (cf. Fig. 3). Disks with radii > 5.0 $^{\prime \prime }$ are too big for a detection with our software (since they would cover large parts of the detector, which makes them unphysical anyway). The S/N-ratio is the S/N per pixel and was calculated as described in Sect. 5.
Star Filter $t_{{\rm exp}}$ $R_{{\rm disk}}$ Sep. Limit S/N

[min] [AU] [ $\hbox{$^{\prime\prime}$ }$ ] [mag/ $\hbox{$^{\prime\prime}$ }^2$ ]

HD 142 J 5 50 2.5 14.2 4.1

75 3.7 16.7 4.3

100 4.9 15.0 3.5

H 5 50 2.5 14.9 3.5

75 3.7 17.1 3.5

100 4.9 16.4 2.5

HD 1237 J 5 50 2.9 16.0 3.6

(=GJ 3021) 75 4.3 16.7 2.7

H 7 50 2.9 14.6 4.0

75 4.3 15.6 3.1

HD 4208 H 8 34 1.0 13.1

50 1.5 14.6 2.5

59 1.8 15.6

75 2.2 15.9 2.7

85 2.5 16.4

100 3.0 16.4 2.1

110 3.3 17.1

136 4.0 17.1

161 4.8 17.7

HD 23079 J 5 50 1.5 13.5 2.3

75 2.2 15.2 2.6

100 2.9 16.0 2.4

HD 33636 J 5 29 1.0 13.5

50 1.8 15.0 2.6

72 2.5 16.7

75 2.6 16.7 3.1

93 3.3 17.5

100 3.5 17.5 2.6

115 4.0 17.5

136 4.8 17.5

HD 52265 J 10 50 1.8 14.2 2.6

75 2.7 16.0 2.6

100 3.6 16.0 2.3

HD 82943 H 2 25 0.9 11.9 1.6

50 1.8 14.6 4.0

75 2.7 16.3 6.0

HD 102647 H 2 25 2.3 13.1 3.6

(= $\beta$ Leo) 50 4.5 14.6 5.1

HD 134987 J 2 25 1.0 13.2 1.8

50 2.0 15.9 3.8

75 3.0 15.9 4.9

H 2 25 1.0 12.3 1.8

50 2.0 13.8 3.2

75 3.0 15.3 3.7

HD 139664 J 3 25 1.5 13.6 2.8

50 2.9 15.1 6.6

75 4.3 15.9 9.1

HD 141569 H 5 500 5.0 14.8 5.2

1000 10.0 15.5 3.7

$K_{\rm s}$ 5 500 5.0 14.5 4.3

1000 10.0 15.3 2.5

HD 155448 H 10 1000 2.0 - -

HD 158643 H 5 500 3.9 13.7 -

(=51 Oph) 1000 8.0 16.2 -

HD 160691 J 2 25 1.7 12.9 2.8

50 3.3 15.1 5.1

75 4.9 15.1 5.1

H 3 25 1.7 13.1 2.8

50 3.3 14.6 5.8

75 4.9 14.6 6.5

HD 163296 H 6 500 4.1 15.5 3.1

1000 8.0 16.2 -

HD 179949 H 1 25 1.0 12.6 2.0

50 1.9 15.3 3.8

75 2.8 16.3 5.5

HD 207129 J 3 25 1.6 12.9 6.5

50 3.2 14.4 6.5

75 4.8 15.1 7.8

HD 217107 J 5 37 1.0 12.3

50 1.4 13.8 2.4

65 1.8 15.2

75 2.1 15.2 3.0

93 2.5 16.7

100 2.7 16.7 3.4

120 3.3 16.7

148 4.0 17.5

176 4.8 17.5

HD 319139 H 5 * ⁽¹⁾ 5.0 18.0 2.9

* ⁽¹⁾ 10.0 17.3 2.7

HR 4796 ⁽²⁾ H 5 100 1.5 12.6 1.0

500 7.5 17.3 2.4

$K_{\rm s}$ 1 100 1.5 11.5 1.4

500 7.5 16.5 2.0

HT Lup H 5 500 3.1 16.4 2.6

1000 6.0 17.6 1.9

$K_{\rm s}$ 5 500 3.1 15.3 2.6

1000 6.0 16.5 2.3

SAO 185668 H 10 * ⁽¹⁾ 1.0 - -

* ⁽¹⁾ 5.0 - -

**Table 2:** Integration times and disk magnitude limits. The latter ones were determined with artificial disks of the sizes shown in this table. No disk was found down to the given surface brightness. The reduction routine has a lower performance for stars in clusters and a determination of brightness limits was sometimes not possible. These cases are indicated with "-''. Estimated errors for the given magnitudes are $\pm$ 0.2 mag. The disk brightness limit as a function of disk radius was studied in more detail for the targets HD 4208, HD 33636 and HD 217107 with further radii 1.0, 1.8, 2.5, 3.3, 4.0 and 4.8 $^{\prime \prime }$ (cf. Fig. 3). Disks with radii > 5.0 $^{\prime \prime }$ are too big for a detection with our software (since they would cover large parts of the detector, which makes them unphysical anyway). The *S/N*-ratio is the *S/N* per pixel and was calculated as described in Sect. 5.
Star	Filter	$t_{{\rm exp}}$	$R_{{\rm disk}}$	Sep.	Limit	S/N
		[min]	[AU]	[ $\hbox{$^{\prime\prime}$ }$ ]	[mag/ $\hbox{$^{\prime\prime}$ }^2$ ]
HD 142	J	5	50	2.5	14.2	4.1
			75	3.7	16.7	4.3
			100	4.9	15.0	3.5
	H	5	50	2.5	14.9	3.5
			75	3.7	17.1	3.5
			100	4.9	16.4	2.5
HD 1237	J	5	50	2.9	16.0	3.6
(=GJ 3021)			75	4.3	16.7	2.7
	H	7	50	2.9	14.6	4.0
			75	4.3	15.6	3.1
HD 4208	H	8	34	1.0	13.1
			50	1.5	14.6	2.5
			59	1.8	15.6
			75	2.2	15.9	2.7
			85	2.5	16.4
			100	3.0	16.4	2.1
			110	3.3	17.1
			136	4.0	17.1
			161	4.8	17.7
HD 23079	J	5	50	1.5	13.5	2.3
			75	2.2	15.2	2.6
			100	2.9	16.0	2.4
HD 33636	J	5	29	1.0	13.5
			50	1.8	15.0	2.6
			72	2.5	16.7
			75	2.6	16.7	3.1
			93	3.3	17.5
			100	3.5	17.5	2.6
			115	4.0	17.5
			136	4.8	17.5
HD 52265	J	10	50	1.8	14.2	2.6
			75	2.7	16.0	2.6
			100	3.6	16.0	2.3
HD 82943	H	2	25	0.9	11.9	1.6
			50	1.8	14.6	4.0
			75	2.7	16.3	6.0
HD 102647	H	2	25	2.3	13.1	3.6
(= $\beta$ Leo)			50	4.5	14.6	5.1
HD 134987	J	2	25	1.0	13.2	1.8
			50	2.0	15.9	3.8
			75	3.0	15.9	4.9
	H	2	25	1.0	12.3	1.8
			50	2.0	13.8	3.2
			75	3.0	15.3	3.7
HD 139664	J	3	25	1.5	13.6	2.8
			50	2.9	15.1	6.6
			75	4.3	15.9	9.1
HD 141569	H	5	500	5.0	14.8	5.2
			1000	10.0	15.5	3.7
	$K_{\rm s}$	5	500	5.0	14.5	4.3
			1000	10.0	15.3	2.5
HD 155448	H	10	1000	2.0	-	-
HD 158643	H	5	500	3.9	13.7	-
(=51 Oph)			1000	8.0	16.2	-
HD 160691	J	2	25	1.7	12.9	2.8
			50	3.3	15.1	5.1
			75	4.9	15.1	5.1
	H	3	25	1.7	13.1	2.8
			50	3.3	14.6	5.8
			75	4.9	14.6	6.5
HD 163296	H	6	500	4.1	15.5	3.1
			1000	8.0	16.2	-
HD 179949	H	1	25	1.0	12.6	2.0
			50	1.9	15.3	3.8
			75	2.8	16.3	5.5
HD 207129	J	3	25	1.6	12.9	6.5
			50	3.2	14.4	6.5
			75	4.8	15.1	7.8
HD 217107	J	5	37	1.0	12.3
			50	1.4	13.8	2.4
			65	1.8	15.2
			75	2.1	15.2	3.0
			93	2.5	16.7
			100	2.7	16.7	3.4
			120	3.3	16.7
			148	4.0	17.5
			176	4.8	17.5
HD 319139	H	5	* ⁽¹⁾	5.0	18.0	2.9
			* ⁽¹⁾	10.0	17.3	2.7
HR 4796 ⁽²⁾	H	5	100	1.5	12.6	1.0
			500	7.5	17.3	2.4
	$K_{\rm s}$	1	100	1.5	11.5	1.4
			500	7.5	16.5	2.0
HT Lup	H	5	500	3.1	16.4	2.6
			1000	6.0	17.6	1.9
	$K_{\rm s}$	5	500	3.1	15.3	2.6
			1000	6.0	16.5	2.3
SAO 185668	H	10	* ⁽¹⁾	1.0	-	-
			* ⁽¹⁾	5.0	-	-

⁽¹⁾ The distances of HD 319139 and SAO 185668 are unknown.
⁽²⁾ A faint object at 4.7 $^{\prime \prime }$ distance to HR 4796 turned out to be a background star, which was also identified by Mouillet et al. (1997).

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