Search for "Extreme" Herbig Be stars using Gaia DR3

Herbig Ae/Be stars are intermediate mass pre-main sequence stars. The massive stars among Herbig Ae/Be stars (Herbig Be stars: B0-B3) are reported to accrete mass through boundary layer accretion, whereas the lower mass Herbig Ae/Be stars accrete through magnetospheric accretion. Interestingly, Herbig Be stars show a bi-modal nature in the near-infrared colors and the Hα equivalent widths. The stars with H-K > 1.0 and Hα EW > 50 Å (emission) are defined as Extreme Herbig Be stars. The difference is attributed to the presence and absence of envelopes around these stars. The total number of known Extreme Herbig Be stars is  11. We investigate the possibility of identifying more extreme Herbig Be stars with high Hα EW taken from Gaia BP/RP spectra and 2MASS NIR colors. We identified 14 candidates that satisfy the criteria of Extreme Herbig Be stars. Confirmation of their evolutionary status using spectroscopic follow-up will increase the total sample of Extreme Herbig Be stars up to 170%.