Updated High-temperature Opacities for the Dartmouth Stellar Evolution Program and Their Effect on the Jao Gap Location
Abstract
The Jao Gap, a 17% decrease in stellar density at M G ~ 10 identified in both Gaia Data Release 2 and Early Data Release 3, presents a new method to probe the interior structure of stars near the fully convective transition mass. The Gap is believed to originate from convective-kissing instability wherein asymmetric production of 3He causes the core convective zone of a star to periodically expand and contract and consequently causes the star luminosities to vary. Modeling of the Gap has revealed a sensitivity in its magnitude to a population metallicity primarily through opacity. Thus far, models of the Jao Gap have relied on OPAL high-temperature radiative opacities. Here we present updated synthetic population models tracing the Gap location modeled with the Dartmouth stellar evolution code using the OPLIB high-temperature radiative opacities. Use of these updated opacities changes the predicted location of the Jao Gap by ~0.05 mag as compared to models that use the OPAL opacities. This difference is likely too small to be detectable in empirical data.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2023
- DOI:
- 10.3847/1538-4357/acb685
- arXiv:
- arXiv:2301.10798
- Bibcode:
- 2023ApJ...944..129B
- Keywords:
-
- Stellar evolution;
- Stellar evolutionary models;
- 1599;
- 2046;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 15 pages, 13 figures