Carina Nebula is the "Astronomy Picture of the Day":
https://apod.nasa.gov/apod/ap240419.html
Stars in the Carina Nebula were observed as part of the Gaia-ESO Spectroscopic Survey. A total of 67 spectra in high-resolution and 6846 spectra in medium resolution were obtained.
The observed stars are part of the following clusters: NGC 3293 (10 Myr), Trumpler 14 (63 Myr), Trumpler 15 (9 Myr), Trumpler 16 (13 Myr), and Collinder 228 (6.8 Myr).
Maria Luiza L. Dantas, postdoc @saga_team , recently published two papers on radial #migration and #lithium depletion.
You can read about her excellent work, and see how these phenomena are connected, in her most recent blog post:
https://www.mlldantas.com/post/visitors-from-the-heart-of-the-milky-way
An international team of astronomers led by Dr Maria Luiza Linhares Dantas, a postdoctoral researcher at the Nicolaus Copernicus Astronomical Centre (CAMK), have made an exciting discovery of a set of 171 old super-metal-rich stars currently located in the solar vicinity. These stars have an estimated age of about 8 billion years. They have chemical elements in amounts 1.5 to 3 times greater than what is found in the Sun. The team determined that these stars were formed between 2 and 4 kpc away
#Hubble featured image of today is the open cluster NGC 2660
See: https://www.nasa.gov/image-feature/goddard/2022/hubble-spies-sparkling-spray-of-stars-in-ngc-2660
Besides the gorgeous view, we can mention that stars in NGC 2660 were observed by the #GaiaESO Survey
It is one of 62 open clusters discussed in https://arxiv.org/abs/2202.04863
In that work, the relation between chemical abundance ratios and ages is investigated taking into account the Galactocentric radius of the clusters
Image Credit: #NASA, #ESA, and T. von Hippel (Embry-Riddle Aeronautical University)
New #GaiaESO paper on Li abundances in old metal-rich dwarfs:
https://arxiv.org/abs/2211.14132
Work lead by Maria Luiza Dantas, post-doc at the SAGA Team
Several authors found that Li abundances in metal-rich dwarfs decrease with increasing metallicity. That is surprising! Metal-rich stars should be younger than the Sun and formed with more Li, not less
Here, we confirm a previous suggestion that the decrease is explained by a population of old stars that migrated from the inner Galaxy
We test a scenario in which radial migration could affect the Li abundance pattern of dwarf stars in the solar neighbourhood. This may confirm that the Li abundance in these stars can not serve as a probe for the Li abundance in the interstellar medium. We use the high-quality data (including Li abundances) from the 6th internal Data Release of the Gaia-ESO survey. In this sample, we group stars by similarity in chemical abundances via hierarchical clustering. Our analysis treats both measured Li abundances and upper limits. The Li envelope of the previously identified radially migrated stars is well below the benchmark meteoritic value (<3.26 dex); the star with the highest detected abundance has A(Li) = 2.76 dex. This confirms the previous trends observed for old dwarf stars (median ages $\sim$ 8 Gyr), where Li decreases for [Fe/H]$\gtrsim$0. This result acts as supporting evidence that the abundance of Li measured in the upper envelope of old dwarf stars should not be considered a proxy for the interstellar medium Li. Our scenario also indicates that the stellar yields for [M/H]>0 should not be decreased, as recently proposed in the literature. Our study backs the recent studies that claimed that old dwarfs on the hot side of the dip are efficient probes of the ISM abundance of Li, provided atomic diffusion does not lower significantly the initial Li abundance in the atmospheres of metal-rich objects.
SagaTeam