Herbig Ae/Be stars towards the dark cloud LDN 1667
  We report the discovery of a new emission-line object, named SPH4-South =
(GAIA EDR3 5616553300192230272), towards the dark cloud LDN 1667. This object
came to our attention after inspecting public images that show a faint diffuse
nebula a few arcsec southern from SPH4, an emission-line object previously
classified as a T Tauri star. We present high-resolution spectra and analyzed
JHK photometry of SPH4 and SPH4-South, and new narrow-band and archival
broad-band images of these objects. A comparison of the spectra of SPH4 and
SPH4-South with high-resolution ones of DG Cir and R Mon, strongly suggests
that SPH 4 and SPH4-South are Herbig Ae/Be stars. The classification of
SPH4-South is further supported by using a k-NN algorithm to its position in
H-K versus J-H color-color diagram. Both stars are detected in the four WISE
bands and the WISE colors allow us to classify SPH4 as a Class I and SPH4-South
as a Class II source. We also show that the faint nebula is most probably
associated with SPH4-South. Using published results on LDN 1667 and the Gaia
Early Data Release 3, we conclude that SPH4 is a member of LDN 1667. The case
of SPH4-South is not clear because the determination of its distance and proper
motion could be affected by the nebulosity around the star, although membership
of SPH4-South to LDN 1667 cannot be ruled out.
