CCD imaging of comets in the range $2.29 \textnormal{ AU} \leq {R}_{\rm h} \leq 5.72 \textnormal{ AU}$ was carried out on the nights of the 8th - 15th June 1999 using the 1m Jacobus Kapteyn Telescope (JKT) on the Island of La Palma. Only the nights of the 8th, 11th, and 13th were photometric. A TEK $1024 \times 1024$ pixel CCD was used at the f/15 cassegrain focus resulting in an image scale of 0.33 arcsec per pixel. All images were taken through Harris V, R, and I band filters, and all cometary images were obtained with the telescope tracking at the sidereal rate of motion. Exposure times of each frame depended on the apparent rate of motion of the object as projected onto the plane of the sky. Exposure times were adjusted so that the comet remained within the FWHM of the stellar-background PSF, which is $\sim$ 0.9 $^{\prime\prime}$ for the JKT under good conditions. This method prevented the comet smearing across the image, which in turn improved the S/N of the target and greatly increased the possibility of detection. Additionally, a direct and more accurate comparison of the cometary profile with that of background stars was therefore possible. Exposure times ranged from 120 to 600 s.

A log of all cometary observations, and the observational circumstances for each of the 25 targeted comets is listed in Table 1. Out of the 25 targeted comets, 15 were positively detected and identified. Object detection was achieved by their known motion relative to the background stars. For the brighter targets, detection was immediate, but for others (particularly 19P/Borrelly and 118P/Shoemaker-Levy 4) several images were shifted and then coadded to reveal the comet by increasing the S/N. Additional search and detection criteria included astrometry of field stars to enable inspection of the exact predicted position of the comet.

The bias level was seen to fluctuate slightly throughout each night of observation, therefore the overscan region of each frame was utilized and each image was subsequently accurately bias-subtracted. Throughout the observing run a series of twilight sky exposures were obtained through each of the V, R, and I band filters. The data on photometric nights was calibrated using the standard field SA 109 from Landolt (1992). For a given filter, the constants from the transformation equations are all consistent at the 1-2 $\sigma$ level for nights 1, 4, and 6, highlighting the stability of the system during the observations.

**Table 1:** Log for all comets observed in June 1999. All images were obtained with the telescope tracking at the sidereal rate. The observing conditions are also specified. The non-photometric data were adequately calibrated using relative photometry of background field stars (see Sect. 1). $R_{\rm h}$ and $\Delta$ are the heliocentric and geocentric distances respectively. $\alpha$ is the phase angle.
Comet	UT date $^{\star}$	$R_{\rm h}$ [AU]	$\Delta$ [AU]	$\alpha$ [deg.]	Observing	Filter	Airmass	Exposure
					conditions $^{\dagger}$			time [s]

2P/Encke	12.191	3.93^I	4.01	14.65	P	2 $\times R$	1.695	120
14P/Wolf	10.102	3.98^I	3.06	7.18	NP	3 $\times R$	1.199	180
	10.099				NP	V	1.187	180
	10.106				NP	I	1.211	180
19P/Borrelly (Night 4)	12.079	5.36^I	4.36	1.98	P	5 $\times R$	2.004	120
	12.070				P	2 $\times V$	1.999	120
19P/Borrelly (Night 6)	14.078	5.36^I	4.35	1.75	P	5 $\times R$	2.010	120
30P/Reinmuth 1	13.163	5.65^A	5.11	9.20	P	3 $\times R$	1.590	300
43P/Wolf-Harrington	13.983	4.46^O	3.66	8.95	P	2 $\times R$	1.871	180
44P/Reinmuth 2	9.023	4.26^I	3.76	12.72	P	R	3.250	600
	9.042				P	2 $\times R$	4.485	300
45P/Honda-Mrkos-Pajdusakova	11.984	5.14^I	4.17	3.69	P	3 $\times R$	1.474	120
46P/Wirtanen	12.033	5.02^O	4.03	2.77	P	3 $\times R$	1.487	120
47P/Ashbrook-Jackson	13.960	4.03^I	3.23	9.97	P	2 $\times R$	1.827	180
	13.961				P	V	1.826	180
	13.968				P	I	1.866	180
49P/Arend-Rigaux	13.944	3.34^O	2.78	16.01	P	3 $\times R$	1.087	180
	13.940				P	V	1.079	180
	13.947				P	I	1.092	180
61P/Shajn-Schaldach	11.022	4.39^I	3.40	3.14	NP	3 $\times R$	1.360	120
64P/Swift-Gehrels	11.144	3.43^I	2.49	8.08	NP	3 $\times R$	1.799	180
67P/Churyumov-Gerasimenko	14.022	5.72^A	4.77	3.89	P	2 $\times R$	1.655	180
69P/Taylor	10.017	4.03^O	3.18	8.90	NP	3 $\times R$	1.147	180
75P/Kohoutek	9.126	4.37^I	3.74	11.26	P	3 $\times R$	1.596	600
83P/Russell 1	14.113	3.01^O	2.14	11.84	P	10 $\times R$	1.152	150
97P/Metcalf-Brewington	9.140	4.76^I	4.11	10.11	P	3 $\times R$	1.159	300
103P/Hartley 2	8.912	4.57^O	4.24	12.52	P	R	1.431	300
	8.931				P	2 $\times R$	1.575	600
	8.917				P	V	1.462	300
104P/Kowal 2	13.922	3.94^O	3.31	12.66	P	3 $\times R$	1.540	240
111P/Helin-Roman-Crockett	9.969	4.35^O	3.49	7.95	NP	3 $\times R$	1.340	240
113P/Spitaler	10.179	4.22^I	3.43	9.59	NP	3 $\times R$	1.753	300
118P/Shoemaker-Levy 4 (Night 3)	11.005	4.71^O	3.72	3.00	NP	3 $\times R$	1.323	120
118P/Shoemaker-Levy 4 (Night 6)	14.051	4.71^O	3.73	3.50	P	10 $\times$ R	1.348	180
121P/Shoemaker-Holt 2	11.036	5.03^O	4.02	1.92	NP	3 $\times R$	1.360	150
137P/Shoemaker-Levy 2	11.182	2.29^I	2.03	15.17	NP	3 $\times R$	1.351	300
	11.177				NP	V	1.350	300
	11.187				NP	I	1.351	300
P/1993 X1 (Kushida-Muramatsu)	11.174	4.11^I	3.74	13.85	P	2 $\times R$	1.625	300

Unfortunately, atmospheric dust and substantial cloud cover during nights 2, 3, 5, 7, and 8 prevented a direct photometric calibration via the use of standard star observations taken on these particular nights. However, it was possible to photometrically calibrate many of the cometary target observations obtained on nights 2 and 3 using relative photometry of background field stars. In other words, we re-observed the stellar fields at the cometary positions of nights 2 and 3 during the next available photometric night. The re-observed stellar fields can thus be calibrated in the normal way and compared with their non-photometric equivalent which contains the comet.

2 Observations and photometric calibration