Related papers: Precise Asteroseismic Ages for the Helmi Streams

While mergers between massive galaxies and their dwarf satellites are well studied, the properties of dwarf - dwarf satellite mergers are not well constrained. Stellar streams trace satellite disruption and, in the dwarf galaxy regime, are…

The availability of asteroseismic constraints for tens of thousands of red giant (RG) stars has opened the door to robust age estimates, enabling time-resolved studies of different populations of stars in the Milky Way. This study leverages…

Using the HST ACS, we have obtained deep optical images reaching well below the oldest main sequence turnoff in fields on the southeast minor-axis of the Andromeda Galaxy, 35 kpc from the nucleus. These data probe the star formation history…

Pisces-Eridanus (Psc-Eri), a nearby ($d$ $\simeq$ 80-226 pc) stellar stream stretching across $\approx$120 degrees of the sky, was recently discovered with Gaia data. The stream was claimed to be $\approx$1 Gyr old, which would make it an…

We provide the first age estimates for two recently discovered white dwarf-red subdwarf systems, LHS 193AB and LHS 300AB. These unusual systems provide a new opportunity for linking the reliable age estimates for the white dwarfs to the…

A candidate diffuse stellar substructure was previously reported in the halo of the nearby dwarf starburst galaxy NGC 4449 by Karachentsev et al. We map and analyze this feature using a unique combination of deep integrated-light images…

Two studies have recently reported the discovery of pronounced Halo substructure in the Sloan Digital Sky Survey (SDSS) commissioning data. Here we show that this Halo substructure is almost in its entirety due to the expected tidal stream…

It has recently been proposed that the dwarf spheroidal galaxies located in the Local Group disks of satellites (DoSs) may be tidal dwarf galaxies (TDGs) born in a major merger at least 5 Gyr ago. Whether TDGs can live that long is still…

Galactic archeology has long been limited by a lack of precise masses and ages for metal-poor stars in the Milky Way's thick disk. However, with TESS providing a growing number of photometric observations, it is possible to calculate masses…

We present a panoramic map of the entire Milky Way halo north of dec~-30 degrees (~30,000 deg^2), constructed by applying the matched-filter technique to the Pan-STARRS1 3Pi Survey dataset. Using single-epoch photometry reaching to g~22, we…

The star formation rate history of the Milky Way is derived using the chromospheric age distribution for 552 stars in the solar neighborhood. The stars sample birthsites distributed over a very large range of distances because of orbital…

Understanding the ages of stars is crucial for unraveling the formation history and evolution of our Galaxy. Traditional methods for estimating stellar ages from spectroscopic data often struggle with providing appropriate uncertainty…

We revisit the problem of low-mass pre-main-sequence (PMS) stellar evolution and its observational consequences for where stars fall on the Hertzsprung-Russell diagram (HRD). In contrast to most previous work, our models follow stars as…

The Eastern Banded Structure (EBS) and Hydra~I halo overdensity are very nearby (d $\sim$ 10 kpc) objects discovered in SDSS data. Previous studies of the region have shown that EBS and Hydra I are spatially coincident, cold structures at…

Determining the evolutionary stage of stars is crucial for understanding the evolution of exoplanetary systems. In this context, Red Giant Branch (RGB) and Red Clump (RC) stars, stages in the later evolution of stars situated before and…

Both observations of arc-like structures and luminosity bursts of stars > 1 Myr in age indicate that at least some stars undergo late infall events. We investigate scenarios of replenishing the mass reservoir around a star via capturing and…

We analyzed the velocity space of the thin and thick-disk Gaia white dwarf population within 100 pc looking for signatures of the Hercules stellar stream. We aimed to identify those objects belonging to the Hercules stream and, by taking…

Stellar streams have become central to studies of the interaction histories of nearby galaxies. To characterize the most prominent parts of the stellar stream around the well-known nearby (d = 17 Mpc) edge-on disk galaxy NGC 5907, we have…

An increasingly popular method to determine stellar ages of red-giant stars for the purpose of Galactic archaeology is asteroseismic grid-based modelling (GBM). In asteroseismic GBM of red-giant stars with solar-like oscillations the large…

We present the first detailed quantitative study of the stellar populations of the Sagittarius (Sgr) streams within the Stripe 82 region, using photometric and spectroscopic observations from the Sloan Digital Sky Survey (SDSS). The star…