2mass photometric system

In article ,
" writes:
the TCS subscripts occur in several temperature-color-[Fe/H]
calibration papers viz. alonso et. al. 1999 \aas 140 261...

That's a good clue. TCS apparently stands for Telescopio Carlos
Sanchez, a 1.5-m in Tenerife. Transformation equations to the
Johnson system are given by Alonso, A., Arribas, S., \&
Martinez-Roger, C.\ 1998, \aaps, 131, 209.

--
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA
(Please email your reply if you want to be sure I see it; include a
valid Reply-To address to receive an acknowledgement. Commercial
email may be sent to your ISP.)