FreeLists / az-observing / [AZ-Observing] Re: SMART-1 Impact Photometry

[Brent A Archinal <barchinal@xxxxxxxx>]

Regarding the brightness of the SMART-1 impact, note that the CFHT images 
were taken in the infrared ("H2 narrow-band filter at  2122 nanometers"), 
so it's difficult to tell what the "~5 mag" estimate of the brightness 
mentioned by Peter Lipscomb would mean visually.
The magnitude 5 ("4.889") that Peter mentions for his image make it sound 
encouraging that this should have been observable visually.  However, here 
it's not clear from the message that Tom Polakis quotes whether this is in 
any way a calibrated magnitude.  Further, Tony Cook has pointed out (
http://www.cs.nott.ac.uk/~acc/Dems/smart1.htm) that since the flash is 
only on a single frame, it could be a cosmic ray hit and it still needs to 
be confirmed that it was taken at the same time as the CFHT flash (and 
predicted impact time).  Perhaps this has been done by now but not yet 
reported.

In any case, it's disappointing that there seem to be no other amateur 
observations, either positive or negative of the flash.  Of several who 
seemed to have tried in Arizona, all were clouded out.

At least the location of the impact, as pointed out by Christen Viellet on 
a representation of the USGS airbrush shaded relief mosaic 
(http://www.cfht.hawaii.edu/News/Smart1/, bottom image), appears to agree 
at about the 1 km level with the predicted impact point based on Tony 
Cook's and our (USGS) topographic models and control network.  It will be 
interesting to see if any surface change can be detected, e.g. with a 
large telescope and good seeing.  At the very least, it should be possible 
for one of the upcoming lunar missions to image this area at high (few m 
or less) resolution and check for evidence of an impact.

- Brent
 

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