The B1Σ+-X1Σ+ emission band system of deuterium fluoride has been recorded with a 10.7-m spectrograph in the wavelength range 205-275 nm. Computer assisted rotational analyses of 41 bands with 0 ≤ v′ ≤ 5 and 16 ≤ v″ ≤ 26 have resulted in precise band origins and rotational parameters for both electronic states. Vibronic term values relative to the energy of v″ = 16 have been obtained through correlated least-squares fitting of the band orgins. The dissociation energy of the ground state has been estimated as De = 49420 ± 35 cm-1 by considering rotational predissociation in the higher vibrational levels. The electronic isotope shift from HF has been determined as ΔTe = -23 ± 5 cm-1. Franck-Condon factors for several values of the rotational quantum number have been generated on the basis of Rydberg-Klein-Rees potentials calculated for both electronic states.