PARAM

Stellar observables

Enter with stellar observed parameters together with their 1σ errors (here assumed to be Gaussian):
Name:
Effective temperature: T _eff = ± K
Metallicity: [Fe/H] = ± dex
Logarithm of surface gravity: logg = ± dex
Luminosity: L = ± L/L_☉
Parallax¹: ϖ = ± mas
Asteroseismic parameters:
Frequency of maximum oscillation power: ν_max = ± μHz
Large frequency separation²: Δν = ± μHz
Period spacing³: ΔP = ± s

¹ Parallax is only taken into consideration when using method 1 step. See more details here.
² For PARSEC models, Δν are computed using scaling relation, while for MESA models, they are computed from the calculations of individual radial-mode frequencies. Read more here.
³ ΔP is only taken into consideration for MESA models.
NOTE: if you do not have a given input parameter, fill in the form with -99.9.

Photometric systems

Choose among the available photometric systems, briefly described here:

and to update the table bellow.

Keep the header and enter apparent magnitudes in the following order:
J J_err H H_err Ks Ks_err 11.847 0.020 11.270 0.020 11.164 0.018

Stellar models

Select the set of evolutionary tracks:
from Bressan et al. (2012), with scaled-solar composition and following the Y=0.2485+1.78Z relation. from Rodrigues et al. (2017), with scaled-solar composition and following the Y=0.2485+1.007Z relation.

Mass-loss on RGB using the Reimers formula with η _Reimers =

Solar values: Δν_☉ = μHz, ν_max _☉ = μHz

Bayesian priors

Select the Bayesian priors:
Flat prior for age in the interval from yr to yr.
Prior on mass -- initial mass function:
Prior on evolutionary stage: Unknown RGB core-He burners (RC)

Methods

Select the Bayesian method:
Method 1 step: it takes into consideration the entire set of parameters and apparent magnitudes to compute the probability density function of all stellar properties, i.e., it does not use the approximation done in the second step of Rodrigues et al. (2014). It can also take into account the parallax as an input parameter. Method 2 steps: it is divided in two steps. First, it computes the probability density function (PDF) of age, mass, radius, mean denstiy, surface gravity, and absolute magnitudes in several passbands, then the absolute magnitude PDFs are combined with apparent magnitudes PDFs (also described as normal distributions), and corrected by values of extinction in the V-band, resulting in a joint PDF of distance modulus and extinction. The maximum of this bidimensional distribution provides the best agreement between distance and extinction for a given set of available apparent magnitudes.

PARAM 1.5

Let's start

Stellar observables

Photometric systems

Stellar models

Bayesian priors

Methods