1. Multiwavelength detection of an ongoing FUOr-type outburst on a low-mass YSO.
- Author
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Guo, Zhen, Lucas, P W, Kurtev, R G, Borissova, J, Elbakyan, Vardan, Morris, C, Bayo, A, Smith, L, Caratti o Garatti, A, Contreras Peña, C, Minniti, D, Jose, J, Ashraf, M, Alonso-García, J, Miller, N, and Muthu, H D S
- Subjects
SPECTRAL energy distribution ,LOW mass stars ,ACCRETION disks ,VARIABLE stars ,OPEN clusters of stars ,TIME series analysis - Abstract
During the pre-main-sequence evolution, Young Stellar Objects (YSOs) assemble most of their mass during the episodic accretion process. The rarely seen FUOr-type events are valuable laboratories to investigate the outbursting nature of YSOs. Here, we present multiwavelength detection of a high-amplitude eruptive source in the young open cluster VdBH 221 with an ongoing outburst, including optical to mid-infrared time series and near-infrared spectra. The initial outburst has an exceptional amplitude of >6.3 mag in Gaia and 4.6 mag in K
s , with a peak luminosity up to 16 L⊙ and a peak mass accretion rate of 1.4 × 10−5 M⊙ yr−1 . The optical to infrared spectral energy distribution of this object is consistent with a low-mass star (0.2 M⊙ ) with a modest extinction (AV < 2 mag). A 100-d delay between optical and infrared rising stages is detected, suggesting an outside-in origin of the instability. The spectroscopic features of this object reveal a self-luminous accretion disc, very similar to FU Orionis, with a low line-of-sight extinction. Most recently, there has been a gradual increase in brightness throughout the wavelength range, possibly suggesting an enhancement of the mass accretion rate. [ABSTRACT FROM AUTHOR]- Published
- 2024
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