NEOWISE Variability of the New Gaia Herbig Ae/Be and Classical Be Stars—Variability Sample and Statistical Analysis

Abstract Light variability is an essential attribute of young stellar objects (YSOs) at the pre-main-sequence (PMS) stage, which can be treated as indicator to trace star formation. We present a statistical study on infrared NEOWISE new and large-sized PMS stars well Herbig Ae/Be (HAeBe) classical Be (CBe) identified from Gaia Data Release 2. A total 3792 (including 714 HAeBe), 417, 473 variable sources were detected catalog 8470 1361 693 CBe, 1309 uncertain (possibly belonging either HAeBe or CBe) stars, respectively. found that 80% variables are dominated by irregular variability, whereas in CBe categories exhibit comparable contributions secular (linear, curved, periodic) stochastic (burst, drop, irregular) variables. This, combination with W1–W2 colors, W4 luminosities, spectral energy distribution slope near- mid-infrared wavelengths, suggests different evolutionary stages uncertain, less more evolved. analysis source properties (e.g., period fractional amplitude) further reveals potential sequence possibly associated disk evolution for types light curves (from linear, periodic, stochastic, nonvariable stars). Possible mechanisms suggested related extinction via circumstellar matter, contribution multiple systems surrounding YSOs, opposed accretion episodic burst).