UVOT mode recommendations

This page is intended to suggest observing modes for Swift's UVOT.  A discussion of the uvot modes is on this page. The mode below are especially recommended for red objects (ie low UV flux compared to their optical flux), but because the UV filters have lower sensitivity and the optical data can be obtained from the ground, weighting the time heavily to the UV is rarely a bad thing.  The optical filters are useful for estimating the reddening as well as for estimating the optical contribution to the uvw2 and uvw1 filters, and with these modes the optical uses a small fraction of the time.  The uvm2 is particularly important since it is the narrowest UV filter and doesn't have a long red tail, thereby giving the best measurement of the UV flux.

Default recommended observing mode for Supernovae in the PPST
6 UVOT filters heavily weighted to the UV -- 0x223f [time weighting w2:m2:w1:u:b:v::5:8:3:1:1:1]

Default recommended observing mode for Supernovae as an uploaded AT
6 UVOT filters heavily weighted to the UV -- 0x0270 (this will do all 6 filters in that ratio for a 1000 second snapshot.  If the snapshot is longer, any extra time is dumped into the uvm2 exposure which is almost always a good thing.

uvw1+u+b+v (ie a target is too faint for the mid-UV filters) -- 0x2238  [w1:u:b:v::6:2:1:1]

There are also special modes for if the SN is too bright (m<13), taking grism spectra (m_uv < 15 or so) or for other filter combinations, but it is probably better to work with a UVOT team member or an ODS to figure out what is appropriate rather than me listing the hundreds of modes that are available.

One should state the filters and weighting desired rather than just the mode (in case you get the mode number wrong or the observing sequence won't give what you think it will give using that mode). 
There might be better modes to get the data you want, but if the mode than the ODS might not know if there is a better way to get what you want.  For most SN observations I recommend adding the following to the filter justification.

"We would like to use the 6 broadband filters (uvw2,uvm2,uvw1,u,b,v) heavily weighted to the uvm2 for better mid-UV sensitivity.   If appropriate, please use UVOT mode 0x0270 for a ToO upload (needs some snapshots longer than 1000 sec to get all six filters) and 0x223f in the PPST to weight the time heavily to the UV."