ELFT HÍRADÓ

[vidakris AT konkoly.hu]

Szemináriumi meghívó / Invitation to a seminar
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CSFK CSI SZEMINÁRIUM / KONKOLY OBSERVATORY SEMINAR

Date: May 29 (Thursday) 14:00


Koshvendra Singh (Tata Institute of Fundamental Research; India)

Accretion Outbursts: A Question and a Probe to the Inner Dynamics of the 
Young Stellar Objects

The disk-mediated accretion onto the young stellar objects (YSOs, 1-2 Msun) 
is often perturbed by episodes of suddenly enhanced accretion rate, known as 
outbursts. The associated timescales are months to centuries and vary from 
one event to another, posing a significant challenge in characterizing the 
outburst-triggering mechanism. Alongside, as outbursts poke the steady 
star-disk system, they provide an unprecedented opportunity to understand the 
dynamics in the inner ~0.1 au region. EX Lupi, a touchstone YSO, has 
undergone multiple outbursts in the last 100 years. In its recent outbursts 
in 2022 and 2024, we discovered that the `hot spot’ is not fixed, but 
migrates over the stellar surface in tandem with a variation in 
mass-accretion rate. Along with this, the hotspot’s thermal structure changed 
from being uniform (before the outburst) to chromatic (during and 
post-outburst), providing insights into how and where matter accretes onto 
the star. In this seminar, I will discuss th
 e case of EX Lupi’s 2022 outburst and our ongoing modeling approach to 
parameterize the thermal-spatial structure of the hotspot, which opens a new 
window on star-disk interaction.


https://konkoly.hu/k-szeminariumok

The seminar will be held live in the Detre hall with audience, but also 
streamed online via Zoom. If you are unable to attend the presentation in 
person, you can join us via this link
https://us06web.zoom.us/j/82806911982?pwd=SVZpT0syQ1J6dHBvSkF4N2dXNEQ0dz09
or the meeting ID: 828 0691 1982 and passcode: 206265



Everyone is welcome!

Krisztián Vida, Ramon Brasser
organizers
https://konkoly.hu/k-szeminariumok