Postdoc: Exploring Interaction Physics of Binary Stars

Organisation/Company KU LEUVEN Research Field Astronomy » Astrophysics Astronomy » Cosmology Researcher Profile Recognised Researcher (R2) Final date to receive applications 5 Aug 2026 - 23:59 (UTC) Country Belgium Type of Contract To be defined Job Status Full-time Offer Starting Date 1 Sep 2026 Is the job funded through the EU Research Framework Programme? Other EU programme Reference Number BAP
- Is the Job related to staff position within a Research Infrastructure? No

We are recruiting two postdoctoral researchers, each focusing on a complementary aspect of the project:
Position A:
Stellar Winds, Mass Loss, and Radiative Transfer Modelling
This position focuses on understanding how stars lose mass and how their winds are accelerated in the late stages of stellar evolution.

The postdoctoral researcher will:

• Derive mass-loss rates and wind properties from high-quality molecular line observations
• Apply and further develop the group’s radiative transfer code POMME to extract detailed physical information from spectral line shapes
• Extend POMME towards a full non-LTE implementation, building on existing developments and integrating fast solvers for the kinetic rate equations
• Investigate dust formation and wind-driving mechanisms by modelling spectral energy distributions, including infrared data
• Analyse a unique sample of well-characterised evolved stars to uncover how mass loss depends on stellar properties such as pulsation, luminosity, temperature, and mass

Position B:
Binary Star Evolution with Gaia
This position focuses on understanding how interactions between stars in binary systems shape their evolution.

The postdoctoral researcher will:

• Develop advanced data-analysis methods to improve orbital and stellar parameters for evolved stars using Gaia DR4 data
• Address challenges related to stellar variability and observational biases by combining astrometric and photometric data
• Analyse large samples of evolved binary stars to map their orbital properties
• Study how processes such as mass transfer, tidal interactions, and angular momentum exchange influence stellar evolution at the population level

Both researchers will play a leading role in their respective research directions, collaborate closely with team members, and contribute to the broader scientific goals of SOPHIA. Postdoc applicants must hold a PhD in astrophysics or an equivalent diploma. Proficiency in English is required.
Position A:
This position is particularly suited for candidates with a strong interest in radiative transfer, computational modelling, spectroscopy, and high-performance scientific coding. Position B:
This position is particularly suited for candidates with an interest in data-intensive astrophysics, statistics, large surveys (e.g. Gaia), and stellar dynamics. The successful postdoctoral applicant will be offered a 1(+1)-year contract (position

A) or 1.5(+1)-year contract (position

B), with the additional 1-year being awarded after positive evaluation. The salary will be commensurate to the standard scale for postdoc researchers in Belgium and will depend on the number of years of experience after PhD. In addition, you will receive a generous package of pay and non-pay benefits, including a holiday bonus, end-of-year bonus, holiday allowance, free hospital insurance, free public transport when commuting, a bicycle allowance, staff discount scheme, access to our sports and cultural facilities at special rates, etc.

The foreseen starting date will be between September 1st 2026 and January 1st 2027 but can be negotiated.
The postdoc will be encouraged to take up training in science and people management, science communication and grant application writing with the aim to develop a personal independent career track as well as engaged in the supervision of bachelor and master students. As part of the employment requirements, postdocs at the IoA have to take up support teaching tasks in one of the Bachelor (in Dutch) or Master (in English) programmes or other service duties, for at maximum of 20% of their working time

The successful postdoctoral applicant will be offered a 1(+1)-year contract (position

A) or…