PARAM 1.4 input form

A web interface for the Bayesian estimation of stellar parameters

See da Silva et al (2006), Rodrigues et al. (2014), and Rodrigues et al. (2017) for details.

PARAM 1.5 is online! Please use the new version.
See Rodrigues et al. (2017) to know how you can combine your available parameters for a star in a useful way! :)

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Stellar observablesEnter with the stellar observed parameters together with their 1σ errors (here assumed to be Gaussian):
Name
Teff=± K, [Fe/H]=± dex

Asteroseismic parameters:

Warning: for PARSEC models, Δν are computed using scaling relations, while for MESA models, they come from individual radial-mode frequencies computed along the tracks.

Δν=± μHz, νmax=± μHz

Warning: ΔP is only taken into consideration for MESA models.

Period spacing: ΔP=± s

Spectroscopic log g:
logg=± dex

Luminosity:
L=± L/L☉
Stellar modelsPARSEC isochrones from Bressan et al. (2012), with scaled-solar composition and following the Y=0.2485+1.78Z relation. The solar metal content is Z☉=0.0152. They include the pre-main sequence phase. Δν and νmax are computed using scaling relations as in Rodrigues et al. (2014). ΔP is not taken into consideration yet, only information of the evolutionary stage.
PARSEC version 1.2s: available 0.0001≤Z≤0.06 (-2.2≤[M/H]≤+0.5); for 0.0001≤Z≤0.02 the mass range is 0.1≤M/M☉<350; for 0.03≤Z≤0.04 0.1≤M/M☉<150, and for Z=0.06 0.1≤M/M☉<20 (cf. Tang et al. (2014) for 0.001≤Z≤0.004, and Chen et al. (2015) for other Z). With revised and calibrated surface boundary conditions in low-mass dwarfs (Chen et al. (2014)), and a slightly improved resolution.
MESA isochrones from Rodrigues et al. (2017), with scaled-solar composition and following the Y=0.2485+1.007Z relation. The solar metal content is Z☉=0.01756 (Paxton et al. (2011) and Paxton et al. (2013)). Individual radial-mode frequencies were calculated for each of the models in the grid, hence Δν were computed. ΔP were also computed along the grid of evolutionary tracks. νmax is computed using scaling relation.
MESA: available for 0.00176≤Z≤0.05553 (-1.0≤[M/H]≤+0.5), in the range 0.6≤M/M☉<2.5. With overshooting in low-mass stars.

Mass-loss on RGB using the Reimers formula with ηReimers= .

Solar values: Δν☉= μHz, νmax☉= μHz

Bayesian priorsFlat 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) non-core He burners (RGB/AGB)
This service is mantained by Léo Girardi and Thaíse Rodrigues at the Osservatorio Astronomico di Padova.
Questions, comments and special requests should be directed to leo.girardi@oapd·inaf·it .
Last modified: Wed Jul 9 12:38:04 2025