;+
; NAME:
;  colatentheat
; PURPOSE: (one line)
;  Return latent heat of sublimation of CO in erg/g from Brown & Ziegler 1980
; CATEGORY:
;  Volatile Transport
; CALLING SEQUENCE:
;  latentheat = colatentheat(t)
; INPUTS:
;  t : temperature, K
; KEYWORD INPUTS
;  None
; OUTPUTS:
;  latentheat : latent heat of sublimation in erg/g
; OPTIONAL OUTPUT
;  None
; RESTRICTIONS:
; PROCEDURE:
;  This function implements the tables of Brown and Zeigler 
; MODIFICATION HISTORY:
;  Written 2011 Apr 10, by Leslie Young, SwRI
;-
function colatentheat, t

; Return CO latent heat of sublimation, in erg/g, as a function of temperature
a_liq  =[1.50598052e1, -6.27448768e2, -4.07696150e3, -7.02090082e4, 0,            0 ]
a_beta =[1.68655152e1, -7.48151471e2, -5.84330795e3,  3.93853859e4, 0,            0 ]
a_alpha=[1.80741183e1, -7.69842078e2, -1.21487759e4,  2.73500950e5, -2.90874670e6, 1.20319418e7]
a=a_beta
if t lt 61.544 then a=a_alpha
if t gt 68.127 then a=a_liq

l = -total( (findgen(4)+1) * t^(- (findgen(4)) ) * a[1:4]) * !phys.k / (28.0061 * !phys.m_u)

return, l

end