2021/05/05 by C. B. Pereira, Pereira, C. B., L. F. Miranda +3
Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Star Formation Studies #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.48550/arxiv.2105.02219
Accepted for The Astronomical Journal, 9 pages, 8 figures, 3 tables; 2 Appendices
arxiv created 2021/05/05 · openalex publication_date 2021/05/05 · arxiv updated 2021/05/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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.