AAVSO Special Notice #74

Sequence available for SN 2007le
October 17, 2007

Further to AAVSO Special Notice #73, "SN 2007le in NGC 7721",
a comparison star sequence has now been added to the AAVSO 
Variable Star Plotter (VSP).  The sequence by A. Henden was 
obtained at SRO based upon a single night of data; the 
calibration is estimated to have a zero-point accuracy of 
approximately 0.03 magnitudes.

This type-Ia supernova is still believed to be prior to
maximum light, and should be observable while still bright.
However, it lies well within the bright spiral galaxy NGC 
7721, and the field is thus heavily contaminated by background 
light from the galaxy itself.  This will make accurate 
photometry of this object very difficult when it goes into 
decline.

An image of the supernova taken at SRO may be found at:

http://www.aavso.org/tmp2/sn2007lev.jpg


Charts for this object may be plotted with VSP:

http://www.aavso.org/observing/charts/vsp/index.html?pickname=SN%202007LE


Please report observations of this supernova to the AAVSO
as "SN 2007LE" (AAVSO Designation 2333-07).

This AAVSO Special Notice was prepared by Matthew Templeton.


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