How do star change morphology from a sphere to a bipolar?

Stars have in general spherical shape, however, when these stars evolve into the asymptotic giant branch and planetary nebula phases, these stars can develop many different shapes, such as ellipse and bipolar. It has been long term debate why these stars develop asymmetric shape. One hypothesis is that there is a binary disk in the centre of the stellar system, and this disk makes outflow from the star focusing to perpendicular to the disk, forming a bipolar outflow.

The project is to work on ALMA data of the prominent bipolar planetary nebulae, including NGC 6302. Nicknamed as a ‘butterfly nebula’ or ‘bug nebula’, the planetary nebula NGC 6302 has clear bipolar outflow traced by ionised gas in the Hubble Space Telescope images. High sensitivity and high angular resolution capabilities of ALMA will enable to study the detailed structure within planetary nebulae. Using molecular and ionised lines, students can trace the gas motion in the core of this planetary nebula, and expected to search for a presence of a binary disk in this system, which could have shaped a bipolar outflow of gas.

This project will be funded by the STFC.
Applicants should apply to the Doctor of Philosophy in Physics and Astronomy with a start date of 1st October 2020.
https://www.cardiff.ac.uk/study/postgraduate/research/programmes/programme/physics-and-astronomy

In the research proposal section of your application, please specify the project title and supervisors of this project. If you are applying for more than one project, please list the individual titles of the projects in the text box provided. In the funding section, please select ’I will be applying for a scholarship/grant’ and specify that you are applying for advertised funding from the STFC.

Applicants will need to submit the following documents with their application:
- post high school certificates and transcripts to date
- academic CV
- personal statement
- two academic references. Your references can either be uploaded with your application, or emailed by the referee to [Email Address Removed] or [Email Address Removed]