MESA-Web Input

This page describes the input parameters appearing on the submission page. For more detailed information about these parameters, consult the full MESA documentation.

Initial Properties

Mass
Initial mass of the star, in solar masses. Must lie in the range [0.1,100].
Metallicity
Initial uniform metallicity of the stellar material, expressed as the mass fraction of metals.
Rotation Rate (ΩZAMS/Ωcrit)i
Initial uniform rotation rate of the star, expressed as the ratio between the rotational angular velocity and the critical angular velocity. Must lie in the range [0.0, 1.0].

Nuclear Reactions

Network
Name of the nuclear reaction network. See MESA-Web Nuclear Reaction Networks for further details.
Custom Nuclear Reaction Rate
Nuclear reaction to customize, expressed in compact notation.
Upload Rate
Name of upload file containing reaction rate data for customized reaction. This file must have the following format:
  • Zero or more lines beginning with a hash (#) mark; these are treated as comments and ignored.
  • Exactly one line consisting of a single integer, giving the number of subsequent T8/rate lines.
  • One or more lines containing a space-separated T8/rate pair, where T8 is the temperature in units of 108 kelvin, and rate is the reaction rate in units of per second.

Interpolation is used to evaluate the rate between the tabulated values.

Mixing

Convection

Mixing Length Alpha (αMLT)
Mixing length, in units of the local pressure scale height. Must be greater than or equal to zero.
Mixing Length Theory Prescription
Implementation of mixing-length theory for convective energy transport; one of:
none
Disable convection, forcing energy transport to be purely radiative
Cox
Prescription described by Chapter 14 of Cox & Giuli (1968)
MLT1
Prescription described by Böhm-Vitense (1958)
MLT2
Prescription described by Böhm & Cassinelli (1971)
Mihalas
Prescription described by Mihalas (1978)
Henyey
Prescription described by Henyey, Vardya, and Bodenheimer (1965)
Boundary Mixing
Prescription for placement and mixing processes at the boundaries of convection zones. Predictive mixing is described in Paxton et al. (2018), and convective premixing (CPM) in Paxton et al. (2019)

Convective Overshoot

Overshoot f
Overshoot scale length parameter, as defined in eqn. 2 of Paxton et al. (2011). Must be greater than or equal to zero.
Overshoot f0
Overshoot boundary offset parameter, as explained below eqn. 2 of Moravveji et al. (2016). Must be greater than or equal to zero.

Semi-Convection

Semi-Convection Alpha (αsemi)
Semi-convection efficiency parameter, as defined in eqn. 12 of Paxton et al. (2013). Must be greater than or equal to zero.

Thermohaline

Thermohaline Alpha (αth)
Thermohaline efficiency parameter, as defined in eqn. 14 of Paxton et al. (2013). Must be greater than or equal to zero.
Thermohaline Mixing Prescription
Implementation of thermohaline mixing; one of:
Kippenhahn
Prescription described by Kippenhahn et al. (1980)
Traxler_Garaud_Stellmach_11
Prescription described by Traxler et al. (2013)
Brown_Garaud_Stellmach_13
Prescription described by Brown et al. (2013)

Winds

Red Giant Branch Wind Prescription
Implementation of wind mass loss on the red giant branch; one of:
Reimers
Prescription described by Reimers (1975)
Blocker
Prescription described by Blöcker (1995)
Kudritzki
Prescription described by Kudritzki et al. (1989)
Nieuwenhuijzen
Prescription described by Nieuwenhuijzen & de Jager (1990)
Vink
Prescription described by Vink et al. (2001)
Grafener
Prescription described by Gräfener & Hamann (2008)
Dutch
Prescription described by Glebbeek et al. (2009)
RGB Wind Scaling Factor
Scaling factor for wind mass loss rate on the red giant branch. Must be greater than or equal to zero.
Asymptotic Giant Branch Wind Prescription
Implementation of wind mass loss on the red giant branch; same options as Red Giant Branch Wind Prescription.
AGB Wind Scaling Factor
Scaling factor for wind mass loss rate on the asymptotic giant branch. Must be greater than or equal to zero.

Numerical Resolution

Spatial (Mass) Resolution - Global

Mesh Delta Coefficient
Spatial grid resolution coefficient. A larger value increases the maximum allowed spacing between grid points, and so decreases the total number of grid points; vice-versa for a smaller value. Doubling the coefficient will roughly (but not exactly) half the number of grid points.

Temporal (Time) Resolution - Global

Variance Control Target
Target value for relative model variation between one timestep and the next. A larger value allows for larger timesteps; vice-versa for a smaller value.
dX_nuc_drop_min_X_limit
Minimum hydrogen mass fraction at which drops in hydrogen abundance, due to nuclear burning, are monitored when choosing timesteps.

Temporal (Time) Resolution - Hydrogen

delta_lg_XH_cntr_min
Logarithm of minimum central hydrogen abundance at which delta_lg_XH_cntr_limit and delta_lg_XH_cntr_hard_limit apply.
delta_lg_XH_cntr_max
Logarithm of maximum central hydrogen abundance at which delta_lg_XH_cntr_limit and delta_lg_XH_cntr_hard_limit apply.
delta_lg_XH_cntr_limit
Limit for change in logarithm of central hydrogen abundance, across a single timestep; timesteps are reduced to attempt to honor this limit.
delta_lg_XH_cntr_hard_limit
Hard limit for change in logarithm of central hydrogen abundance, across a single timestep; timesteps are reduced to guarantee this limit is honored.

Custom Stopping Condition

Quantity
Quantity to monitor to decide when to stop the calculation.
Value
Corresponding value to monitor.

General

Detailed Profile Output Frequency
Number of timesteps between consecutive profile (detailed structure) files.
MESA Release
Release (version) of the MESA code to use for calculations. Leave as the default value unless trying to reproduce legacy calculations.
Email Address
Email address to send Zip archive to, upon job completion (either through the stopping condition being met, or the 2-hour time limit being reached; whichever comes first). See the MESA-Web Output page for details of the contents of the archive.
Updated 2024-03-08 06:26:59