I am a first year PhD researcher working with the white dwarfs and transients research group. My supervisors are Deanne Coppejans, and Danny Steeghs. I study AM CVn stars (a sub-class of binary white dwarf stars) in the radio spectrum using data from the VLA.

Fundamental questions remain about the accretion and outflow physics of cataclysmic variable stars, and their compact binary counterparts, AM CVn systems. Using observations from the Karl J. Jansky Very Large Array (VLA), I have obtained the deepest radio constraints to date, for two such AM CVn systems: AM CVn and HP Lib. By cross-matching with other large scale surveys such as LOFAR and VLASS, the radio emission properties and mechanisms of AM CVn and CV populations can be better characterised. A key question this study aims to contribute to is whether the emissions observed in CVs are due to flares in the atmosphere of the donor star, as compared to transient jets originating from the accretion disk. Understanding outflows from accreting white dwarfs such as these can propel our undestanding of the Type Ia supernovae progenitors. (Paper in prep)

I completed my MSci at the University of Birmingham with my final year dissertation on machine learning applications for radio astronomy, with a focus on classification of radio objects from MeerKAT. I also work with the GOTO and ePESSTO+ collaborations for follow-up and data analysis on transients.

Research/Publications

First author:

• Constraints on Radio Emissions from AM CVn Systems; Anwesha Sahu et al., in prep
• (MSci Dissertation) Machine Learning Applications for Radio Astronomy, May 2023

Co-author:

• Classifying Optical (Out)bursts in Cataclysmic Variables: The Distinct Observational Characteristics of Dwarf Noave, Micronovae, Stellar Flares and Magnetic Gating; Ilkiewicz et al., 2024
• Evolution of Spin in the Intermediate Polar CC Sculptoris; Paice et al., 2024
• The fast transient AT 2023clx in the nearby LINER galaxy NGC 3799, as a tidal disruption event of a very low-mass star; Charalampopoulos et al., 2024
• Eruptive mass-loss less than a year before the explosion of
  superluminous supernovae: I. The cases of SN 2020xga and SN 2022xgc; A. Gkini et al., in prep
• The partial tidal disruption of a star on a 700-day orbit around a supermassive black hole; Makrygianni et al., in prep
• SN 2023tsz: A helium-interaction driven supernova in a very low mass galaxy; B. Warwick et al., in prep

Research Talks

• I presented a talk on my current project titled 'Upper limits on radio emissions from AM CVn type stars - SNe Ia progenitors' at a Royal Astronomical Society Specialist Discussion Meeting (SDM) on 8 November 2024. The SDM was titled 'Progress in Astrophysics with Type Ia Supernovae third meeting (PATIAS-3)'.

Past Research

• Using the MeerKAT Galactic Plane Survey and the VLA FIRST survey, I constructed a deep learning model to identify and classify radio objects within the MeerKAT GPS using a GAN (generative adversarial network). This project was performed as a preparatory study for an automated classification algorithm to identify radio objects with the Square Kilometre Array (SKA) 
• Due to inaccurate weather outputs from on-site weather stations at the SPECULOOS South Observatory, Paranal, Chile, resulting in a reduction in observation time, I constructed an algorithm which analyses the sky conditions in real-time from an on-site All-Sky camera. This provided accurate sky conditions with accuracies of over 90% which would result in an increase in observation time, thus aiding the detection of transits with longer durations.
• During my third year of my BSc/MSci, I calculated habitable exoplanet occurrence rates around K dwarf stars, using a simulated set of stars from TRILEGAL, and performed asteroseismology investigations, in preparation for the upcoming ESA PLATO mission.

Meetings & Conferences

• AM CVn 5 - 5th International Workshop on AM CVn Binaries. 5-8 September 2023, Armagh Observatory and Planetarium, Northern Ireland, UK
• What was that? - Planning ESO Follow up for transients, variables, and solar system objects in the era of LSST. 22-26 January, ESO Garching
• Machine Learning for Transient Science, University of Warwick, December 2023 (delivered a talk)
• UK Transients 2024, University of Leicester, UK, 3rd June 2024
• 30 years of superluminal motion in GRS 1915+105, Royal Astronomical Society, UK, 10th May 2024
• Celebrating 21 years of Astronomy at Warwick, University of Warwick, UK, 4th - 6th Sept. 2024 (delivered a talk)
• Progress in Astrophysics with Type Ia Supernovae third meeting (PATIAS-3), Royal Astronomical Society, 8th November 2024 (delivered a talk)

Outreach/Engagement

• Astronomy & Astrophysics Representative at the Postgrad Student Staff Liaison Committee, Department of Physics, University of Warwick.
• Speaker for talks at local schools and astronomical societies
• Organiser for Machine Learning for Transient Science, Warwick 2023
• Chair and Outreach Officer, University of Birmingham's Astronomical Society from 2020 - 2023.
• Find out more about my public outreach engagements and watch talks I have delivered on my website, Sitara Tales.
• You can check my LinkedIn for other current/past engagements.

Awards/Scholarships

• Warwick Astrophysics PhD Prize Scholar (2023/24 entry), University of Warwick

Teaching

• Year 1 electronics lab sessions demonstrator
• Year 1 physics undergraduate math support sessions