High-contrast SB2 spectroscopic systems with peculiar early-type component(s)

10 Mar 2024
Job Information

Organisation/Company

Astronomical Institute of the Slovak Academy of Sciences

Department

Stellar Dept.

Research Field

Astronomy » Astrophysics

Researcher Profile

First Stage Researcher (R1)

Country

Slovakia

Application Deadline

15 May 2024 - 23:59 (Europe/Brussels)

Type of Contract

Not Applicable

Job Status

Negotiable

Hours Per Week

40

Offer Starting Date

1 Sep 2024

Is the job funded through the EU Research Framework Programme?

Not funded by an EU programme

Is the Job related to staff position within a Research Infrastructure?

No

Offer Description

Supervisor: Dr. Martin Vaňko ([email protected] )
Affiliation: Astronomical Institute of the Slovak Academy of Sciences, Stellar Department, Tatranská Lomnica
Syllabus
Focus of the research: The easiest proof that a system is a binary star is the presence of eclipses. The second most useful technique is radial-velocity (RV) variations. Such variations are typically detected within spectroscopic surveys, which result in a list of objects catalogued according to their specific stellar attributes. Once such a variation has been detected, targeted and systematic observations must be obtained to characterize the system. In the simplest case, the binary comprises two components of relatively close luminosity which results in two systems of spectral lines in the composed spectrum. When the components differ significantly in luminosity, spectral lines of the fainter secondary component become less evident. The situation gets especially difficult when the secondary is a fast rotator (> 100 km/s). Although the spectral lines of the fast-rotating secondary component are shallow and hard both to identify and model, its light boosts the continuum level, which uniformly reduces the depths of the dominant component’s spectral lines. More rarely, a star might be revealed to be double when discrepancies in the projected rotational velocity, v sin i, determined using spectral lines that have a different sensitivity to the atmospheric effective temperature are detected, e.g., the lines of Mg II at λ 4481 Å and Ca II H and K.
Objectives: Modelling the spectroscopic data of several peculiar, high-contrast, early-type systems on the main sequence with a combination of photometric measurements from the archive of the TESS satellite. The main goal is to determine the RVs and rotational velocities of the studied objects and the possible presence of other components. Our analysis will also be focused on characteristic of possible short-term (tens of minutes) or medium-term (several hours) pulsations of individual components, determination of their atmospheric parameters (surface temperature, metallicity, surface gravity) and absolute parameters (radius, mass, luminosity). Based on the obtained results, the evolutionary status of studied systems will be discussed.
Requirements: good knowledge of English, good knowledge of programming, ability to work independently with literature.
Research field: Binary and multiple stellar systems

Requirements

Research Field

Astronomy » Astrophysics

Education Level

Master Degree or equivalent

Languages

ENGLISH

Level

Good

Research Field

Astronomy » Astrophysics

Additional Information
Work Location(s)

Number of offers available

1

Company/Institute

Astronomical Institute of the Slovak Academy of Sciences

Country

Slovakia

City

Vysoke Tatry

Postal Code

059 60

Street

Tatranska Lomnica

Geofield

Where to apply

E-mail

[email protected]

Contact

City

Vysoke Tatry

Website

http://www.astro.sk

Street

Tatranska Lomnica, PO Box 18

Postal Code

05960

E-Mail

[email protected]
[email protected]

Phone

(+421) 52 79 89 111

STATUS: EXPIRED