Tootfinder

MESA Isochrones and Stellar Tracks (MIST) III. The White Dwarf Cooling Sequence
Evan B. Bauer, Aaron Dotter, Charlie Conroy, Tim Cunningham, Minjung Park, Pier-Emmanuel Tremblay
https://arxiv.org/abs/2509.21717

MESA Isochrones and Stellar Tracks (MIST) III. The White Dwarf Cooling Sequence
We present a substantial update to the MESA Isochrones and Stellar Tracks (MIST) library, extending the MIST model grids and isochrones down the white dwarf (WD) cooling sequence with realistic physics for WD cooling timescales. This work provides a large grid of MESA models for carbon-oxygen core WDs with hydrogen atmospheres (spectral type DA/DC), descended from full prior stellar evolution calculations. The model tracks, isochrones, and WD cooling timescale contours are available on the MIST…

PARSEC V2.0: Rotating tracks and isochrones for seven addtional metallicities in the range Z=0.0001-0.03
C. T. Nguyen, G. Costa, A. Bressan, L. Girardi, G. Cescutti, A. J. Korn, G. Volpato, Y. Chen, G. Pastorelli, M. Trabucchi, K. G. Shepherd, G. Ettorre, S. Zaggia
https://arxiv.org/abs/2508.02393 …

PARSEC V2.0: Rotating tracks and isochrones for seven addtional metallicities in the range Z=0.0001-0.03
PARSEC v2.0 rotating stellar tracks were previously presented for six values of metallicity from subsolar to solar values, with initial rotation rates ($ω_\mathrm{i}$, defined as the ratio of angular velocity and its critical value) spanning from the non-rotating case to very near the critical velocity (i.e. $ω_\mathrm{i}=0.99$), and for initial masses covering the $\sim 0.7 M_\odot$ to $14 M_\odot$ interval. Furthermore, we provided the corresponding isochrones converted into several photome…

A novel approach to determining the age of stellar clusters: application to NGC 188
K. Yakut, B. Kalomeni, S. Rappaport
https://arxiv.org/abs/2508.09255 https://

A novel approach to determining the age of stellar clusters: application to NGC 188
We present a new independent determination for the age of one of the oldest open clusters, NGC 188: $6.41 \pm 0.33$ Gyr. We utilize a novel approach where we jointly fit the radial velocities (RVs) and spectral energy distributions (SED) of six binary star systems in the cluster. The joint fit has 21 free parameters: 12 stellar masses, 6 orbital inclination angles, as well as a common cluster age, distance, and extinction, $A_V$. The fit to the SEDs utilizes MIST stellar isochrones, and the fit…

Crowning the Queen: Membership, Age, Rotation, and Activity for the Open Cluster Coma Berenices
M. A. Ag\"ueros (Columbia University, Laboratoire d'astrophysique de Bordeaux), J. L. Curtis (Columbia University), A. N\'u\~nez (Columbia University), C. Burhenne (Rutgers), P. Rothstein (Columbia University), B. J. Shaham (Columbia University), K. Singh (Columbia University), P. Bergeron (Universit\'e de Montr\'eal), M. Kilic (University of Oklahoma), K. R. Covey (West…

Crowning the Queen: Membership, Age, Rotation, and Activity for the Open Cluster Coma Berenices
Despite being only 85 pc away, the open cluster Coma Berenices (Coma Ber) has not been extensively studied. This is due in part to its sparseness and low proper motion, which together made Coma Ber's membership challenging to establish. Gaia data for $\approx$400 previously cataloged candidate cluster stars allowed us to identify $\approx$300 as members. With [Fe/H] measurements for nine members, we found that Coma Ber has a solar metallicity, and then fit isochrones to its color--magnitude dia…

Constraining the helium-to-metal enrichment ratio $\Delta Y/\Delta Z$ from nearby field stars using Gaia DR3 photometry
N. Ricci, G. Valle, M. Dell'Omodarme, P. G. Prada Moroni, S. Degl'Innocenti
https://arxiv.org/abs/2509.24376

Constraining the helium-to-metal enrichment ratio $ΔY/ΔZ$ from nearby field stars using Gaia DR3 photometry
We investigate the feasibility of accurately determining the helium-to-metal enrichment ratio, $ΔY/ΔZ$, from Gaia DR3 photometry for nearby low-mass main sequence field stars. We selected a sample of 2770 nearby MS stars from the Gaia DR3 catalogue, covering a Gaia $M_G$ absolute magnitude range of 6.0 to 6.8 mag. We computed a dense grid of isochrones, with $ΔY/ΔZ$ varying from 0.4 to 3.2. These models were then used to fit the observations using the SCEPtER pipeline. The fitted values ind…