Nami Mowlavi

Research

 Department of Astronomy
 University of Geneva
 Switzerland

 Tel: +41 22 37 92 194
 Nami.Mowlavi<at>unige.ch
 http://obswww.unige.ch/~mowlavi

CV

Projects

Research

My current research mainly focus on stellar variability. It comprises both observational and theoretical aspects. Some of them are described below.

Selected Research Topics

Periodic variable stars

   Variability tree
 

  Variability tree: the zoo of variable objects (Fig. 1 in Eyer & Mowlavi 2009)

Variable stars can be classified in various types. Among them, periodic variables represent an important category.

The origin of the periodicity can be stellar pulsation, rotation modulation (involving inhomogeneities at the surface of rotating stars), or multiplicity (systems with two or more stars orbiting each other). Each type leads to unique opportunities to study stars. Obviously, the discovery of a new type of variable star is very important.

My research in this area comprises the study of periodic variables in open clusters and of eclipsing binaries in large scale surveys.

Selected publications

  -  Stellar variability in open clusters. I. A new class of variable stars in NGC 3766 (Mowlavi et al. 2013, A&A 554, A108)
ESO Press release
On the interpretation of new late B- and early A-type periodic variable stars in NGC 3766 (Mowlavi et al. 2014, in Putting A Stars into Context, 3-7 June 2013, Moscow, Press-Menu)
On the new late B- and early A-type periodic variable stars (Mowlavi et al. 2014, IAU Symp. 301, 43)


Transient objects

   Example of transients
 

  Light curves of transient stars showing bursts and outbursts (Fig. 16 in Mowlavi 2014).

Some stars exhibit sudden light curve variations that are limited in time. Those transient behaviors result from specific physical processes such as instabilities (of nuclear or physical origin), mass loss, shocks, or energy dissipation. They occur on time scales from seconds to years, and often (but not always) at unpredicted times.

Searching, identifying and analyzing them is an active field of research using large scale surveys.

Selected publications

  -  Searching transients in large-scale surveys - A method based on the Abbe value (Mowlavi 2014, A&A 568, A78)


Stellar age determinations

   Binary age determination
 

  Example of age determination of stars in two binary systems (adapted from Fig. 28 of Mowlavi et al. 2012). The continuous lines are isochrones, i.e. locations of models of similar ages.

How old is a star observed in the sky? How much nuclear fuel has it already consumed? How long will it still live? These are some questions we would like to answer for as many stars as possible. The answers are crucial for many aspects of astrophysics, including our understanding of the formation and evolution of our Galaxy.

Stellar age determination can be attempted on single stars, on stars that are part of binary or multiple systems, or on stars belonging to stellar clusters. Accurate grids of stellar model predictions are key inputs for such determinations. Such models are constructed at the Geneva Observatory.

Selected publications

  -  Stellar mass and age determinations - I. Grids of stellar models (Mowlavi et al. 2012, A&A 541, A41)

Data

Selection of large scale surveys used in my research:

Observations

Many nights spent observing at



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   Last update: 09 Oct 2014, 7:03