First VLF detections of ionospheric disturbances due to Soft Gamma ray Repeater SGR J1550-5418 and Gamma Ray Burst GRB 090424

TL;DR

This paper reports the first detection of ionospheric disturbances caused by a Soft Gamma Ray Repeater and a Gamma Ray Burst using VLF signals, expanding understanding of space weather effects.

Contribution

It presents the first observations of ionospheric disturbances from SGR and GRB events using VLF monitoring stations in India, demonstrating a novel detection method.

Findings

Detected ionospheric disturbances linked to SGR J1550-5418 and GRB 090424

Confirmed VLF signals can be used to monitor space weather events

Expanded the global database of GRB and SGR ionospheric effects

Abstract

We present the first report of the detection of sudden ionospheric disturbances (SIDs) due to a Soft Gamma Ray Repeater (SGR) SGR J1550-5418 and a Gamma Ray Burst (GRB) GRB 090424. These detections were made with receiving stations of Indian Centre for Space Physics which were monitoring Very Low Frequency signals (VLFs) from the VTX transmitter located at the southern tip of Indian sub-continent. These positive detections add to the list of a handful of similar detections of other GRBs and SGRs throughout the world.