2000 July 19: Comet recorded in clearer skies this evening - rather than a hazy spot [July 16] it now sports a short tail in the 'electronic finder' pointing directly upwards as it hangs some 20o above the northern horizon of London - but little chance of observing it visually from WPO. The colour images via MX5c continue to record the 'preceding' blue and 'following' yellow colours on the 5m and 10m Star-2000 exposures. The spectra continue to record little except reflected sunlight despite the longer exposure and sharper [untrailed] spectrum.
Successfully used the SX Star-2000 software to simultaneously autoguide the telescope and capture the full image on the SX camcorder CCDs in the MX9 [spectra] and MX5c [single-shot colour]. Half-way through the main exposure, the guide and image 'interlaced frames' are automatically swapped to seamlessly complete the main exposure. Any star within the full image can be used for autoguiding but the effective exposure [of the main image] is half the value in the image captions. I used the comet's bright inner coma moving rapidly westwards at non-sidereal rate - the bright streaks offset at an angle are field stars and spectra 'moving' relative to the 'stationary' comet.
2000 July 16: My first view and record
of Comet Linear - now circumpolar and at its brightest [~mag 6] at a fair
altitude midway between Polaris and Capella due north over the 'glow' of
London. Success this evening [after the previous night's frustration]
by piggybacking the widefield electronic finder [85mm fl f/2 lens +SX-M
framestore with rapid refresh] on the LX200 to immediately locate the Comet
as a slightly fuzzy star in the co-ordinate field. The Comet's rapid
motion westwards detectable over a 5 - 10 second period on the downloaded
CCD images via the LX200 at 2m focal length.
text & images copyright Maurice Gavin 2000