[BAA Comets] 2016 apparition of Comet 29P/S-W1 : Call for observations

[Richard Miles]

Dear Observer,

Comet 29P/Schwassmann-Wachmann is currently making a return to our early 
morning skies after having passed through conjunction with the Sun. This 
marks the start of its 2016 apparition.

Accurate photometric observations of the comet are sought early on so that 
coverage this year is maximised and as many outbursts as possible detected 
and measured. If you wish to join this year's observing campaign then do 
please consider taking a series of frames totaling at least 10-30 minutes so 
as to ensure good signal to noise. (Am happy to advise further as necessary, 
or to reduce stacked fits images provided.) It's better not to use a filter, 
especially when the comet is quiescent, since we are looking for small 
changes in brightness due to minor outbursts, which may otherwise go 
undetected,

Photometry should be done using UCAC-4 as the reference catalogue together 
with a measuring aperture either 10" square or 11.3" diameter (or as close 
to either of these dimensions as you can depending on your CCD pixel size).

Southern hemisphere observing locations are favourably placed as the comet 
is currently at about -26deg Dec and approaching an elongation of 34deg. 
Last year, the comet hugged the galactic equator and so passed through some 
dense star fields making accurate study difficult. Fortunately, it is now 
moving to more northerly galactic latitudes and will reach +15deg by the 
start of April and remain observable through to December (reaching -22 Dec. 
and +20 galactic latitude).

The plan is to collect as much photometric data as possible in both 2016 and 
2017. The intention is to produce a paper based on the results of accurate 
photometry during the four 2014-2017 apparitions and all observers 
contributing useful photometry will be acknowledged as co-authors.

Richard Miles
BAA