An international team of astronomers has investigated EX Lupi—a young T-Tauri star in the constellation of Lupus and an archetype of EXor stars. The study, presented in a paper published August 23 on the pre-print server arXiv, provided important insights into the accretion history of this star.
Located some 514 light years away, EX Lupi is a variable star with a mass of about 0.6 solar masses and a radius of 1.6 solar radii. It represents the prototype of young eruptive stars known as EXors—low-mass pre-main sequence (PMS) stars whose episodic eruptions are due to temporarily increased accretion.
EX Lupi has been monitored since 1893, what revealed several large outbursts: in 1945, 1955, and 2008. However, although the star has been extensively observed for over 100 years, its accretion history is still not fully understood.
That is why a group of astronomers led by Mu-Tian Wang of the Nanjing University in China decided to re-analyze the available observational data regarding EX Lupi. They assembled the light curve of EX Lupi from 1895 to 2023 to assess the role of accretion bursts and outbursts in this star.
“With the improved knowledge about the variability link between mass accretion rate and photometry, we return to the century-long photometry data of EX Lupi to measure the mass accreted in bursts and compare that to the mass accreted during quiescence,” the researchers explained.
2023-08-31 09:48:03
Link from phys.org rnrn