Observations in July 2002

On the nights of 2002 July 25--27 little data was obtained largely due to the poor atmospheric conditions on La Palma. High winds and dust forced us to close the dome shortly after twilight on the first night. Severe dust extinction and a gradual decline in the seeing hindered observations on the second and third nights. Table 5.3 lists the targets observed through very severe dust extinction on the first night before we were forced to close the dome.

Table 5.3: Observations on 2002 July 25 through the HiRac I filter at the NOT.

Target	Object type	Number of exposures	Image size (pixels)
Gliese 569	Multiple brown dwarf	21000	288 x 288
NGC7008	Planetary nebula progenitor	8000	288 x 288
WR 140	Wolf Rayet binary system	8000	288 x 288

There was less dust extinction on the second night, but the seeing gradually deteriorated from $0.5$ $as$ to $1.2$ $as$. The charge transfer efficiency of the camera appeared to be poorer for some of the runs on this night. The targets observed are listed in Table 5.4.

Table 5.4: Principle observations on 2002 July 26. Runs where the detector was saturated or the target drifted out of the field have been excluded. The seeing conditions gradually deteriorated, reaching $1$--$1.2$ $as$ for the last few runs.

Target	Object type	Filter	Number of exposures	Image size (pixels)
CVS 97A	Gravitational lens	HiRac I	20000	624 x 288
M13	Globular cluster core	HiRac I	10000	624 x 288
M15	Globular cluster core	HiRac I	12000	624 x 288
M15	Globular cluster core*	HiRac I	4000	624 x 288
M15	Globular cluster core*	Coherent R	4000	624 x 288
M15	Globular cluster core	Coherent R	4000	624 x 288
M15	Globular cluster mosaic	HiRac I	12000	624 x 288
NGC7469	Active Galactic Nucleus	HiRac I	4000	624 x 288
NGC7469	Active Galactic Nucleus	780 nm edge	10000	624 x 288
M32	Galactic Nucleus	780 nm edge	4000	624 x 288
ADS 15828	Binary	HiRac I	7000	624 x 122
ADS 191	Binary	HiRac I	4000	624 x 122
8 Lacertae	Binary	HiRac I	4000	624 x 288

The optical filters used on the second night provided a range of different bandpasses between $600$ $nm$ and $1$ $\mu m$. Table 5.5 lists the general properties of the filters used. The bandpasses of two of the filters used are also shown in Figure 5.5.

Table 5.5: Filters used for the observations in 2001 and 2002.

Filter name	Centroid of observing band	Filter description
Coherent R	650 nm	Top hat filter with 72 nm FWHM
HiRac I	810 nm	Top hat filter with 125 nm FWHM
780 edge	~860 nm	Long-pass filter (long wavelength cutoff set by limit of the CCD detector)

On the third night (2002 July 27) the seeing typically ranged from $1.5$ $as$ to $2.3$ $as$, and little useful data was obtained.