tides3.f

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      SUBROUTINE tides3(QPERI,M1,M2,VSTAR,HI,ECC,DE)
*
*
*       GR tidal energy loss for interacting stars.
*       -------------------------------------------
*
      IMPLICIT REAL*8 (a-h,m,o-z)
      REAL*8  de(2)
*
*
*       Specify constants in N-body units.
      gm = 1.0
      c = 3.0d+05/vstar
      fac = (gm/c**2)**3.5
*
*     FE = 1.0 + 73.0/24.0*ECC2 + 37.0/96.0*ECC**4
*     FE2 = SQRT(ECC**2 - 1.0D0)*(301.0/ ....
*       Adopt simplified eccentricity factor near ECC = 1.
      ge = 425.0*3.1415/(32.0*sqrt(2.0d0))
*
*       Set mass and pericentre expression in N-body units.
      fm = sqrt(m1 + m2)*m1**2*m2**2/qperi**3.5
*       Form energy change in N-body units (total in DE(1)).
      de(1) = 8.0/15.0*fac*fm*c**2*ge
      de(2) = 0.0
*
*       Obtain specific energy change for diagnostic purposes.
      mu = m1*m2/(m1 + m2)
      dh = de(1)/mu
*
*       Print diagnostics for capture of hyperbolic orbit.
      IF (hi.GT.0.0.AND.dh.GT.hi) THEN
          WRITE (6,5)  m1, m2, hi, dh, de(1), qperi
    5     FORMAT (' CAPTURE CHECK!    M1 M2 H DH DE QP ',
     &                                1p,6e9.1)
      END IF
*
      RETURN
*
      END