# Multi-epoch VLBI of a double maser super burst

## TL;DR

This study presents a high-cadence, multi-epoch VLBI investigation of rare maser super bursts in two star-forming regions, providing detailed insights into their extreme flux increases and polarization properties.

## Contribution

It offers one of the first detailed, high-resolution observational analyses of maser super bursts using multiple VLBI arrays during a rapid response campaign.

## Key findings

- Detection of flux increases above 30,000 Jy and 18,000 Jy in W49N and G25.65+1.05
- High-resolution polarization data obtained during the bursts
- Multi-epoch VLBI data revealing temporal evolution of maser emission

## Abstract

In a rare and spectacular display, two well-known massive star forming regions, W49N and G25.65+1.05, recently underwent maser 'super burst' - their fluxes suddenly increasing above 30,000 and 18,000 Jy, respectively, reaching several orders of magnitude above their usual values. In quick-response, ToO observations with the EVN, VLBA and KaVA were obtained constituting a 4 week campaign - producing a high-cadence multi-epoch VLBI investigation of the maser emission. The combination of high-resolution, polarisation and flux monitoring during the burst provides one of the best accounts, to date, of the maser super burst phenomenon, aiding their use as astrophysical tools. These proceedings contain the preliminary results of our campaign.