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euraxess logohr logoJob offer : 3-year contract (H2020_AdG 2020: Project 101019953 ISSP)

Level : PostDoc, PHD required

Salary : Depending on experience (48.8k€ to 69.1 k€)

Type of position : postdoc position with research activities in stellar physics, fundamental parameters of stars, interferometric observations, asteroseismology data analysis, and stellar atmosphere models

Situation : Université Côte d’Azur – Observatoire de la Côte d’Azur - Laboratoire LAGRANGE – Bâtiment Fizeau du Campus Valrose (Nice) & Calern Observatory for remote observations

Description of Observatoire de la Côte d’Azur

Observatoire de la Côte d’Azur is a French public Center for research in earth sciences and astronomy. With more than 450 persons working at four different locations (Nice Observatory, Université de Nice, Sophia Antipolis, Plateau de Calern), its role is to explore, understand and transfer knowledge about Earth sciences and astronomy, whether in astrophysics, geosciences, or related sciences such as mechanics, signal processing, or optics. OCA is composed of 3 research units (ARTEMIS, GEOAZUR, and LAGRANGE) and 1 support structure (GALILEE). This program will be developed in the Lagrange Laboratory.

The Interferometric Survey of Stellar Parameters (ISSP) ERC-Adv grant, started on 1 Sep 2021 for 5 years, aims at realizing and exploiting an ambitious and homogenous survey of the angular diameters of a thousand stars as faint as magnitude 8 in the visible and as small as 0.2 milliseconds of arc. It takes benefit of the recently commissioned CHARA/SPICA instrument installed on the CHARA Array, Mount Wilson Observatory (USA, CA). The survey is built to address key questions about the relation between planets and stars and to offer to the broader community a unique and primary source of direct information on a representative and large sample of stars all over the HR diagram. The ISSP team is opening this postdoc position to support the scientific programs of the survey, benefiting from 200 nights of observation over the four coming years (~1 week/month, mostly through our remote facility at Observatoire de la Côte d’Azur), and especially about the complementarity between interferometric and asteroseismic measurements of stars.

Description of the position

This position is focused on the S02 and S03 SPICA programs aiming at obtaining direct interferometric measurements of F5-K7 stars known as asteroseismic targets (~100 dwarfs and ~200 giants, respectively). This program is closely related to the ESA PLATO mission for which CHARA/SPICA aims at producing reliable interferometric measurements before the operation (extraction of non-seismic parameters of stars in the PLATO Input Catalog) and during the operation through follow-up programs. Managing these observing programs in coordination with the co-investigators of the ISSP survey will be one of the main tasks of this position. The second main aspect will be to interpret the interferometric measurements and the asteroseismic data together with existing stellar atmosphere models and additional data like spectroscopy and photometry for the optimal extraction of stellar radius and stellar effective temperature. Apart from the case-by-case basis, the overall analysis will permit comparing and understanding the possible difference of estimations, one of the overall objectives being to calibrate seismic scaling relations before the launch of the PLATO mission. It is expected that the methods that will be developed will benefit to the whole ISSP survey.
Some knowledges in asteroseismology and interferometry are important for this position, especially for what concerns the estimation of stellar fundamental parameters. We also expect candidates with a good knowledge of 1D and 3D stellar atmosphere models. While staying in this general framework and taking advantage of the expertise of the ISSP team, the project will be adapted to the background of the candidate. Synergies between the different positions will permit to benefit from the different scientific activities of the ISSP survey.
This team welcomes applicants with diverse backgrounds and experiences. We regard gender equality and diversity as a strength and an asset.
Main activities

Identification of existing asteroseismic data and selection of priority targets.

  • Observations with the CHARA/SPICA instrument and the CHARA Array. Data reduction. Exploitation of the interferometric data for the optimal extraction of stellar fundamental parameters.
  • Use of stellar atmosphere models for the optimal constraints on the stellar parameters.
  • Global analysis of the sample; calibration of seismic scaling relations.
  • Reporting, publications
  • Collaboration on tools with other persons in the team


A knowledge of asteroseismology is important for this position. We expect candidates with a good knowledge of 1D and 3D stellar atmosphere models and with expertise in determining stellar radius and effective temperature. Some knowledge of optical interferometry would be of course ideal, together with an interest in observing.


This position assumes that the candidate will undertake observations, and they will be required to travel to (1) the United States at Mount Wilson in California for some onsite observations, and (2) the remote observatory at the Plateau de Calern site of the Côte d´Azur Observatory for most of the observations.


The initial deadline is fixed to 20 Dec 2022. Interviews will be organized in January 2023, with a starting date for the contract to be discussed during the interview, but the sooner the better.

Application must be sent by email to denis.mourard@oca.eu. The application should contain a detailed CV, a letter of motivation describing the interest for the position and the skills for the activities that are described. Letters of recommendation (maximum 2) should be sent directly by the reference persons to denis.mourard@oca.eu