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Below we highlight examples of diagrams and figures that were constructed using MESA-Web data. These examples are submitted by students and professionals across the globe as an example of how MESA-Web can aide in the understanding of astrophysical phenomena which can be best understood with hands on, real scientific data!

To submit your work for consideration in being featured on our site please submit (1) .pdf file or .mpeg file of your example, the input parameters used for your MESA-Web model(s), and a brief explanation of the scenario depicted.

All submissions should be send via email to: m e s a - w e b - i n f o (at) asu . edu.

8 June 2015

The first plot below is produced from the history file which lists summary profile of 2327 computed models of which the first 773 correspond to the pre-MS stage and the rest to evolution from ZAMS stage for a period of about 11 Gyr. The ZAMS point (red dot) corresponds to 774th model. The black dot shows the sun aged about 4.69 Gyr as a model for the current age of 4.57 Gyr was not available.

Color-Magnitude (HR) diagram of a 1 solar mass star starting from its pre-MS stage, settling down to steady conditions at the ZAMS stage, slowly moving towards the turn-off point where the star slowly begins to expand and cool down and finally accelerates its expansion to become a red giant later on.

The second plot shown below is a two-in-one plot which draws both log⁡(L/L_⨀ ) and T_eff versus model simulation age in Gyr. The descent to RGB stage has been shown up to < 4500 K as the simulation run had stopped. The details of the interesting pre-MS evolution occurring over 37.3 Myr are shown in Fig 2 below. As before the ZAMS point (red dot) and current point (black dot) are indicated. We can see that the point where the stellar interior conditions become steady is some distance behind the red dot as no model profile (structure) data corresponding to that point was included in the simulation run.

Details of pre-MS evolution of a solar mass star are shown here over a period of some 37.3 Myr after which settling to the ZAMS stage can be seen. The left side ordinate shows the logarithmic luminosity while the right side ordinate shows the effective temperature. The star is in a steady state now as an MS star with conditions changing very slowly over a time scale of ~ 10 Gyr as shown in Fig 3 below.

Here we can see the complete MS phase during which the star slowly becomes hotter reaching a level of about 5800 K after 6.5 Gyr and then starts slow cooling because of expansion although the luminosity is increasing. A rapid increase of luminosity and coincident decrease of temperature starts after 11 Gyr taking the star to its RGB phase. The current state of Sun is also shown (black/blue dots).

Submitted by Mandyam Anandaram,
Bangalore University

20 May 2015

Here I show a Hertzsprung-Russel (HR) diagram for eight solar metallicity stars with initial masses between one to eight solar masses. An HR diagram plots the surface luminosity on the y-axis as a function of descending surface temperature on the x-axis. These diagrams are extremely useful in determining the evolutionary stages of various types clusters. For example, for a relatively young cluster, we may find most stars lie on the main sequence. The contrary can be said for older clusters where stars have turned off of the main sequence and become giants evolving upwards to the the right of the HR diagram.


Submitted by Carl Fields,
Undergraduate Student
Arizona State University
2014 MESA Summer School Graduate
Joint Institute for Nuclear Astrophysics