Computer Ephemeris for 2018 from DE200/LE200.

First page.

Epoch T = J2018.5 = date 2018 Jul 2.625 (JD2458302.125) = besselian epoch B2018.50167

Beginning of spring: Mar 20  16h16.40m
             summer: Jun 21  10h 8.38m
             autumn: Sep 23   1h55.26m   
             winter: Dec 21  22h23.86m

Earth in perihelion: Jan 03   5.60h
         aphelion  : Jul 06  16.80h

Mean obliquity of ecliptic (eps) at J2018.5:
                        23.436885o = 23o26'12.79"
  Sin(eps) = 0.39773863          Cosec(eps) = 2.51421391
  Cos(eps) = 0.91749876            Sec(eps) = 1.08991973
  Tan(eps) = 0.43350318            Ctg(eps) = 2.30678815

Year precessional quantities for J2018.5:
     -- in right ascension    m =  46.1295"   =   3.07530s
     -- in declination        n =  20.0415"   =   1.33610s
     -- in longitude          p =  50.2951"   =   0.0139709o
     -- lunar/solar          p1 =  50.3887"   =   0.0139969o
     -- planetary            q1 =   0.1020"   =   0.0000283o

Ecliptic rotation:
   angular velocity of --        pi =   0.4699"    =   0.0001305o
   longitude of real axis of --  Pj = 175.0454o

Accumulated angle from J2000.0 to T:
-- precession in longitude        a =    930.421"  =   0.258450o
-- of ecliptic rotation           b =      8.694"  =   0.002415o
-- precession in right ascension  M =      56.8931s
-- precession in declination      N =     370.7683"

Tm = (J2000.0 + T) / 2
180o - Pj + a/2  for Tm             c =   5.1683o
180o - Pj - a/2  for Tm             c'=   4.9099o

Matrix for transformation from J2000.0 to J2018.5
     0.99998983    -0.00413714    -0.00179760
     0.00413714     0.99999144    -0.00000372
     0.00179760    -0.00000372     0.99999838