MDM Trouble Report for 2002 May 19

Telescope: 1.3m
Observer(s): Burke, Fields, Zou (OSU)
Instrument: Echelle

Problem(s) Encountered:
High winds cause telescope to bounce EW direction at modest airmass.
Had highest winds for our run.  winds average 17mph with gusts up to 22mph
At modest airmass, >1.6, PSFs were highly elongated in EW direction resulting in unusable images.
This was due to high frequency bouncing back and forth in the EW directio when gust buffeted telescope.
This was not due to overguiding.  The guider camera showed the stars bouncing EW even when guding was turned off,
also bouncing was higher frequency than the guide updates.
We went to zenith and the bouncing no longer occured.
This suggests the telescope is out of balance.
We tried several different airmass positions and the bouncing increased with increasing airmass.
We closed the dome doors and this helped marginally, but the final solution was to wait until our target was at lower airmass.
In hindsight the EW elongation of the PSF was noticed on earlier days of observing, but it was very mild.  
It seems the winds need to be moderately high >~17mph for the elongation to be severe.


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Submitted on 2002 May 19 [4:26:51]